This document provides an introduction and overview of cryogenic rocket engines. It discusses the history of cryogenics and rocket propulsion. Some key points include:
- Cryogenic rocket engines use cryogenic (very cold) liquid fuels that must be kept cold to remain in liquid form, like liquid oxygen and liquid hydrogen.
- The Space Shuttle used cryogenic fuel in its main engines. Only a few countries have mastered cryogenic rocket technology.
- Cryogenic engines provide high performance but require heavy insulation for fuel storage. They are more complex than non-cryogenic designs.
- The document outlines the major components and operating cycles of cryogenic rocket engines. It also discusses the combustion process and fuel injection methods
Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that are stored at very low temperatures below -150°C. The United States first developed cryogenic rocket engines in 1963. Key components include the combustion chamber, injectors, turbo pumps, and nozzle. Cryogenic engines offer high energy density but present challenges like leakage and embrittlement. India successfully launched its first indigenous cryogenic upper stage in 2014. Future engine technologies being researched include ion engines and nuclear thermal rockets.
PRESENTATION ON CRYOGENIC ROCKET ENGINESelf-employed
This document provides information about a seminar on cryogenic rocket engines presented by Jaison Cyril. It discusses what cryogenics is, provides a history of cryogenic rocket engines including the RL10 engine, describes the construction and working principle of cryogenic engines including different power cycles, lists applications and advantages and disadvantages of cryogenic engines. It also summarizes the four phases of combustion in the thrust chamber and discusses potential next generation rocket engines.
Cryogenics is the study of materials at very low temperatures below -150°C. Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that must be stored at extremely cold temperatures to remain liquid. The first country to use a cryogenic engine was the USA in 1963, while Russia developed its own in 1983. India has successfully developed its own cryogenic upper stage powered by the CE-7.5 cryogenic engine. Cryogenic engines offer very high energy density and clean, economical propellants but also present challenges related to storage and handling of the cryogenic liquids.
This document discusses cryogenic rocket engines (CRE). It begins by defining cryogenics as the study of operations and behaviors of materials at temperatures below -150°C. It then discusses that CRE use cryogenic liquid propellants like liquid oxygen and liquid hydrogen, which must be stored at extremely low temperatures. The document outlines the various CRE developed around the world by countries like the US, Japan, France, China, Russia. It also discusses the challenges in developing CRE and India's indigenous developments like the CE7.5 and CE20 engines.
Cryogenic rocket engines use cryogenic fuels such as liquid hydrogen and liquid oxygen that are stored at very low temperatures. They provide several advantages including high energy density and producing only water exhaust, but also have challenges like boil off and leakage due to the extreme cold temperatures required. India's first unmanned lunar mission in 2008 failed when the indigenous cryogenic upper stage engine did not ignite as planned. Future rocket technologies being researched include ion engines, nuclear thermal engines, and other alternatives to further space exploration.
Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that must be stored at very low temperatures to remain in liquid form. The document discusses the history and development of cryogenic rocket engines. It provides details on the major components of cryogenic engines like the combustion chamber, fuel injector, and turbo pumps. It also explains the different cycles used in cryogenic engines like gas generator and staged combustion. The combustion process in the thrust chamber involves rapid mixing and vaporization of the cryogenic fuels.
Cryogenic rocket engines use liquid oxygen and liquid hydrogen propellants that are stored at extremely low cryogenic temperatures. They provide several advantages like high energy density and clean, non-toxic exhaust but also have challenges like boil off rates and leakage of the reactive cryogenic fuels. The document traces the history of cryogenic engines from early US and Soviet designs to current engines used by various countries. It describes the key components and working of cryogenic engines and concludes by discussing future engine technologies still under development.
This document provides an overview of cryogenic rocket engines. It discusses that cryogenic fuels require storage at extremely low temperatures to remain liquid, and the most widely used combination is liquid hydrogen and liquid oxygen. The major components of cryogenic rocket engines are described, including the combustion chamber, injectors, pumps, valves and tanks. Advantages are high energy density and clean, non-toxic exhaust, while challenges include difficulties storing cryogenic liquids for long periods. Common applications are in rockets utilizing these high-performance fuels.
Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that are stored at very low temperatures below -150°C. The United States first developed cryogenic rocket engines in 1963. Key components include the combustion chamber, injectors, turbo pumps, and nozzle. Cryogenic engines offer high energy density but present challenges like leakage and embrittlement. India successfully launched its first indigenous cryogenic upper stage in 2014. Future engine technologies being researched include ion engines and nuclear thermal rockets.
PRESENTATION ON CRYOGENIC ROCKET ENGINESelf-employed
This document provides information about a seminar on cryogenic rocket engines presented by Jaison Cyril. It discusses what cryogenics is, provides a history of cryogenic rocket engines including the RL10 engine, describes the construction and working principle of cryogenic engines including different power cycles, lists applications and advantages and disadvantages of cryogenic engines. It also summarizes the four phases of combustion in the thrust chamber and discusses potential next generation rocket engines.
Cryogenics is the study of materials at very low temperatures below -150°C. Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that must be stored at extremely cold temperatures to remain liquid. The first country to use a cryogenic engine was the USA in 1963, while Russia developed its own in 1983. India has successfully developed its own cryogenic upper stage powered by the CE-7.5 cryogenic engine. Cryogenic engines offer very high energy density and clean, economical propellants but also present challenges related to storage and handling of the cryogenic liquids.
This document discusses cryogenic rocket engines (CRE). It begins by defining cryogenics as the study of operations and behaviors of materials at temperatures below -150°C. It then discusses that CRE use cryogenic liquid propellants like liquid oxygen and liquid hydrogen, which must be stored at extremely low temperatures. The document outlines the various CRE developed around the world by countries like the US, Japan, France, China, Russia. It also discusses the challenges in developing CRE and India's indigenous developments like the CE7.5 and CE20 engines.
Cryogenic rocket engines use cryogenic fuels such as liquid hydrogen and liquid oxygen that are stored at very low temperatures. They provide several advantages including high energy density and producing only water exhaust, but also have challenges like boil off and leakage due to the extreme cold temperatures required. India's first unmanned lunar mission in 2008 failed when the indigenous cryogenic upper stage engine did not ignite as planned. Future rocket technologies being researched include ion engines, nuclear thermal engines, and other alternatives to further space exploration.
Cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that must be stored at very low temperatures to remain in liquid form. The document discusses the history and development of cryogenic rocket engines. It provides details on the major components of cryogenic engines like the combustion chamber, fuel injector, and turbo pumps. It also explains the different cycles used in cryogenic engines like gas generator and staged combustion. The combustion process in the thrust chamber involves rapid mixing and vaporization of the cryogenic fuels.
Cryogenic rocket engines use liquid oxygen and liquid hydrogen propellants that are stored at extremely low cryogenic temperatures. They provide several advantages like high energy density and clean, non-toxic exhaust but also have challenges like boil off rates and leakage of the reactive cryogenic fuels. The document traces the history of cryogenic engines from early US and Soviet designs to current engines used by various countries. It describes the key components and working of cryogenic engines and concludes by discussing future engine technologies still under development.
This document provides an overview of cryogenic rocket engines. It discusses that cryogenic fuels require storage at extremely low temperatures to remain liquid, and the most widely used combination is liquid hydrogen and liquid oxygen. The major components of cryogenic rocket engines are described, including the combustion chamber, injectors, pumps, valves and tanks. Advantages are high energy density and clean, non-toxic exhaust, while challenges include difficulties storing cryogenic liquids for long periods. Common applications are in rockets utilizing these high-performance fuels.
The document discusses the principles and operation of ramjet engines. A ramjet relies on forward air compression through the engine intake to generate thrust, requiring high-speed flight. It has no moving parts for compression. Air entering the intake is slowed in a supersonic diffuser, then combustion and expansion in the engine accelerates the exhaust faster than inlet air to produce thrust. The HyFly program demonstrated a dual-combustion ramjet concept for hypersonic cruise flight at Mach 6 with a liquid hydrocarbon fuel. While ramjets have low drag and can operate at high pressures and temperatures, they also have limitations such as altitude restrictions and lower efficiency compared to engines with mechanical compression like turbojets.
The document discusses cryogenic rocket engines. It begins with definitions of cryogenics and describes how cryogenic rocket engines use liquid oxygen and liquid hydrogen propellants at extremely low temperatures. It then covers the history, principles, major components like the combustion chamber and nozzle, operation, advantages like high energy density, and drawbacks such as boil off rates of cryogenic rocket engines. In conclusion, it discusses how cryogenic rocket engines are promising for future space exploration due to their high performance.
This document provides information about cryogenic rocket engines. It discusses that cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that are stored at very low temperatures. The key components of cryogenic engines include thrust chambers, turbo pumps, gas generators and cryogenic valves. The document explains that cryogenic engines generate thrust via the combustion of cryogenic fuels in the thrust chamber, which accelerates the exhaust gases through a converging-diverging nozzle. It also provides details about the working, advantages and disadvantages of cryogenic rocket propulsion technology.
This document discusses nuclear thermal propulsion for space applications. It begins by introducing the concept and some historical programs in the US and Russia. It then discusses the benefits of nuclear thermal propulsion such as high efficiency and payload capacity compared to chemical rockets. The document goes on to describe three types of nuclear energy sources - fission, radioactive isotope decay, and fusion - that have been investigated for heating propellant. It provides details on nuclear fission and isotope decay rockets and components of a nuclear fission reactor before concluding with a comparison of advantages and disadvantages of nuclear rockets.
Cryogenic rocket engines use cryogenic (extremely cold) liquid fuels like liquid hydrogen and liquid oxygen that provide high performance. They work by pumping the cryogenic liquids into a combustion chamber where they are burned, producing hot gas that is expelled through a nozzle to generate thrust. Some key advantages are high specific impulse (efficiency) and payload capacity, but they also have challenges with storing the cryogenic fuels. The document discusses the history, principles, components, propellants, and working of cryogenic rocket engines. It focuses on the Space Shuttle Main Engine as a prominent example.
This presentation aims at introducing cryogenic fuel and cryogenic engine to non-specialists. It tries to convey in a synthetic form the essential features of cryogenic engineering and to raise awareness on key design and construction issues of cryogenic engine technology at a cryogenic temperature (i.e., .123 K). This basically uses the liquid oxygen and liquid hydrogen as an oxidizer and fuel, which are very clean and non-pollutant fuels compared to other hydrocarbon fuels like: Petrol, Diesel, Gasoline, LPG, CNG, etc., sometimes, liquid nitrogen is also used as an fuel. The efficiency of the rocket engine is more than the jet engine. As per the Newton’s third law of mechanics, the thrust produced in rocket engine is outwards whereas that produced in jet engine is inwards. This paper also deals with the modern trends and expected future outcomes.
This seminar gives idea about spacecraft propulsion i.e., actually what are different latest modes of propulsion are used in space agency and also the introduction of combustion of propellants.
Introduction Cum Need for a Scramjet Engine
History
Working
More information about Scramjet Engines
Hyper X Vehicle
Applications of scramjet engines
Challenges to scramjet engine technology
Conclusion
References
For further explanation:
https://www.youtube.com/watch?v=0Ux7mYSlAfg
Rocket propellants can be either solid or liquid. Solid propellants store fuel and oxidizer together in a solid casing, while liquid propellants store fuel and oxidizer separately in tanks. Liquid propellants provide higher efficiency but require complex pumping systems, while solid propellants are simpler but provide lower efficiency. Rocket performance is measured by specific impulse, with higher values indicating more thrust per unit of propellant. Careful fuel measurement and propellant mixing ratios are required to achieve optimal rocket performance.
Jet propulsion systems use gas turbines for aircraft propulsion. Gas turbines are light, compact, and have a high power-to-weight ratio. They operate on an open cycle where air is compressed, mixed with fuel and combusted, and the hot gases are expanded to produce thrust. Common jet propulsion systems include turbojets, turbofans, and turboprops which partially or fully expand combustion gases in a turbine before exiting through a nozzle.
1) A turbocharger uses the engine's exhaust gases to drive a turbine connected to an air compressor, increasing air intake and allowing more fuel to be burned for higher engine power.
2) Types of superchargers include centrifugal, roots, and vane compressors, while turbochargers consist of a turbine and compressor on a shared shaft.
3) Advantages of superchargers and turbochargers include increased engine power, especially at high altitudes, while disadvantages include added cost, complexity, and risks of detonation.
Hybrid rockets use a liquid oxidizer and solid fuel. They are mechanically simpler than other rocket types and can provide denser fuels. A hybrid rocket consists of a pressure vessel containing liquid oxygen and a combustion chamber housing solid fuel. When thrust is desired, the liquid oxidizer flows into the combustion chamber where it reacts with the solid fuel surface in a boundary layer flame. Hybrid rockets offer higher safety during fabrication and operation compared to solid rockets, and allow for throttling capability not available with other rocket types. While hybrid rockets currently have some performance disadvantages, their safety features make them promising for future propulsion applications.
Jet engines work by taking in air, compressing it, mixing it with fuel and igniting it to produce hot exhaust gases. These gases are then channeled through a turbine which powers the compressor. The fast moving exhaust gases exit through a nozzle to produce thrust that propels aircraft. Early jet engines were developed in the 1900s but came into widespread use after WWII to power military aircraft due to their superior speed over propeller planes. Modern jet engines include variants like turbofans used on most commercial planes.
This document discusses different types of rocket propulsion systems. It describes solid, liquid, gas, and hybrid rocket propellants. Solid propellant rockets have the fuel and oxidizer pre-mixed and stored in the rocket casing. Liquid propellant rockets store the fuel and oxidizer separately and pump them into the combustion chamber. Hybrid rockets combine aspects of solid and liquid rockets. The document also discusses factors to consider when selecting rocket fuels such as physical properties, performance, economic factors, and health and safety issues.
SOLID ROCKET PROPULSION PPT ( SPACE SOLID ROCKET ).pptxAmarnathGhosh8
Rocket propulsion is a class of jet propulsion that produces thrust by ejecting burned propellant. The thrust is generated on the basis of Newton's third law of motion. Rocket propulsion systems can be broadly classified according to the type of energy source (chemical, solar, electric, or nuclear).
This document provides information about jet propulsion and different types of jet engines. It discusses the history of jet engines beginning with designs from ancient Egypt. The key components of a basic jet engine are described including the fan, compressor, combustor, turbine, mixer, and nozzle. Jet engines work by sucking in air, compressing it, adding fuel, combusting the mixture, and expelling the hot gases through a nozzle to produce thrust. The main types of jet engines are then outlined - ramjet, turbojet, turbofan, turboprop, and turboshaft - along with brief descriptions of each.
This Presentation gives a brief idea on turbojet engines, their components, working principle and also on the materials used in both the hot and cold sections of the engine, applications, etc..
Gas turbines operate by compressing air, adding fuel and igniting it to generate high-temperature gas, and expanding this gas through a turbine to power the compressor and provide output shaft work. There are various types including turbojets used in aircraft, turboprops which drive propellers via reduction gears, and turbofans which have a large fan at the front and achieve higher efficiency. Ramjets have no moving parts and rely solely on forward speed for compression, making them unable to produce static thrust.
The document discusses the principles and operation of ramjet engines. A ramjet relies on forward air compression through the engine intake to generate thrust, requiring high-speed flight. It has no moving parts for compression. Air entering the intake is slowed in a supersonic diffuser, then combustion and expansion in the engine accelerates the exhaust faster than inlet air to produce thrust. The HyFly program demonstrated a dual-combustion ramjet concept for hypersonic cruise flight at Mach 6 with a liquid hydrocarbon fuel. While ramjets have low drag and can operate at high pressures and temperatures, they also have limitations such as altitude restrictions and lower efficiency compared to engines with mechanical compression like turbojets.
The document discusses cryogenic rocket engines. It begins with definitions of cryogenics and describes how cryogenic rocket engines use liquid oxygen and liquid hydrogen propellants at extremely low temperatures. It then covers the history, principles, major components like the combustion chamber and nozzle, operation, advantages like high energy density, and drawbacks such as boil off rates of cryogenic rocket engines. In conclusion, it discusses how cryogenic rocket engines are promising for future space exploration due to their high performance.
This document provides information about cryogenic rocket engines. It discusses that cryogenic rocket engines use cryogenic fuels like liquid oxygen and liquid hydrogen that are stored at very low temperatures. The key components of cryogenic engines include thrust chambers, turbo pumps, gas generators and cryogenic valves. The document explains that cryogenic engines generate thrust via the combustion of cryogenic fuels in the thrust chamber, which accelerates the exhaust gases through a converging-diverging nozzle. It also provides details about the working, advantages and disadvantages of cryogenic rocket propulsion technology.
This document discusses nuclear thermal propulsion for space applications. It begins by introducing the concept and some historical programs in the US and Russia. It then discusses the benefits of nuclear thermal propulsion such as high efficiency and payload capacity compared to chemical rockets. The document goes on to describe three types of nuclear energy sources - fission, radioactive isotope decay, and fusion - that have been investigated for heating propellant. It provides details on nuclear fission and isotope decay rockets and components of a nuclear fission reactor before concluding with a comparison of advantages and disadvantages of nuclear rockets.
Cryogenic rocket engines use cryogenic (extremely cold) liquid fuels like liquid hydrogen and liquid oxygen that provide high performance. They work by pumping the cryogenic liquids into a combustion chamber where they are burned, producing hot gas that is expelled through a nozzle to generate thrust. Some key advantages are high specific impulse (efficiency) and payload capacity, but they also have challenges with storing the cryogenic fuels. The document discusses the history, principles, components, propellants, and working of cryogenic rocket engines. It focuses on the Space Shuttle Main Engine as a prominent example.
This presentation aims at introducing cryogenic fuel and cryogenic engine to non-specialists. It tries to convey in a synthetic form the essential features of cryogenic engineering and to raise awareness on key design and construction issues of cryogenic engine technology at a cryogenic temperature (i.e., .123 K). This basically uses the liquid oxygen and liquid hydrogen as an oxidizer and fuel, which are very clean and non-pollutant fuels compared to other hydrocarbon fuels like: Petrol, Diesel, Gasoline, LPG, CNG, etc., sometimes, liquid nitrogen is also used as an fuel. The efficiency of the rocket engine is more than the jet engine. As per the Newton’s third law of mechanics, the thrust produced in rocket engine is outwards whereas that produced in jet engine is inwards. This paper also deals with the modern trends and expected future outcomes.
This seminar gives idea about spacecraft propulsion i.e., actually what are different latest modes of propulsion are used in space agency and also the introduction of combustion of propellants.
Introduction Cum Need for a Scramjet Engine
History
Working
More information about Scramjet Engines
Hyper X Vehicle
Applications of scramjet engines
Challenges to scramjet engine technology
Conclusion
References
For further explanation:
https://www.youtube.com/watch?v=0Ux7mYSlAfg
Rocket propellants can be either solid or liquid. Solid propellants store fuel and oxidizer together in a solid casing, while liquid propellants store fuel and oxidizer separately in tanks. Liquid propellants provide higher efficiency but require complex pumping systems, while solid propellants are simpler but provide lower efficiency. Rocket performance is measured by specific impulse, with higher values indicating more thrust per unit of propellant. Careful fuel measurement and propellant mixing ratios are required to achieve optimal rocket performance.
Jet propulsion systems use gas turbines for aircraft propulsion. Gas turbines are light, compact, and have a high power-to-weight ratio. They operate on an open cycle where air is compressed, mixed with fuel and combusted, and the hot gases are expanded to produce thrust. Common jet propulsion systems include turbojets, turbofans, and turboprops which partially or fully expand combustion gases in a turbine before exiting through a nozzle.
1) A turbocharger uses the engine's exhaust gases to drive a turbine connected to an air compressor, increasing air intake and allowing more fuel to be burned for higher engine power.
2) Types of superchargers include centrifugal, roots, and vane compressors, while turbochargers consist of a turbine and compressor on a shared shaft.
3) Advantages of superchargers and turbochargers include increased engine power, especially at high altitudes, while disadvantages include added cost, complexity, and risks of detonation.
Hybrid rockets use a liquid oxidizer and solid fuel. They are mechanically simpler than other rocket types and can provide denser fuels. A hybrid rocket consists of a pressure vessel containing liquid oxygen and a combustion chamber housing solid fuel. When thrust is desired, the liquid oxidizer flows into the combustion chamber where it reacts with the solid fuel surface in a boundary layer flame. Hybrid rockets offer higher safety during fabrication and operation compared to solid rockets, and allow for throttling capability not available with other rocket types. While hybrid rockets currently have some performance disadvantages, their safety features make them promising for future propulsion applications.
Jet engines work by taking in air, compressing it, mixing it with fuel and igniting it to produce hot exhaust gases. These gases are then channeled through a turbine which powers the compressor. The fast moving exhaust gases exit through a nozzle to produce thrust that propels aircraft. Early jet engines were developed in the 1900s but came into widespread use after WWII to power military aircraft due to their superior speed over propeller planes. Modern jet engines include variants like turbofans used on most commercial planes.
This document discusses different types of rocket propulsion systems. It describes solid, liquid, gas, and hybrid rocket propellants. Solid propellant rockets have the fuel and oxidizer pre-mixed and stored in the rocket casing. Liquid propellant rockets store the fuel and oxidizer separately and pump them into the combustion chamber. Hybrid rockets combine aspects of solid and liquid rockets. The document also discusses factors to consider when selecting rocket fuels such as physical properties, performance, economic factors, and health and safety issues.
SOLID ROCKET PROPULSION PPT ( SPACE SOLID ROCKET ).pptxAmarnathGhosh8
Rocket propulsion is a class of jet propulsion that produces thrust by ejecting burned propellant. The thrust is generated on the basis of Newton's third law of motion. Rocket propulsion systems can be broadly classified according to the type of energy source (chemical, solar, electric, or nuclear).
This document provides information about jet propulsion and different types of jet engines. It discusses the history of jet engines beginning with designs from ancient Egypt. The key components of a basic jet engine are described including the fan, compressor, combustor, turbine, mixer, and nozzle. Jet engines work by sucking in air, compressing it, adding fuel, combusting the mixture, and expelling the hot gases through a nozzle to produce thrust. The main types of jet engines are then outlined - ramjet, turbojet, turbofan, turboprop, and turboshaft - along with brief descriptions of each.
This Presentation gives a brief idea on turbojet engines, their components, working principle and also on the materials used in both the hot and cold sections of the engine, applications, etc..
Gas turbines operate by compressing air, adding fuel and igniting it to generate high-temperature gas, and expanding this gas through a turbine to power the compressor and provide output shaft work. There are various types including turbojets used in aircraft, turboprops which drive propellers via reduction gears, and turbofans which have a large fan at the front and achieve higher efficiency. Ramjets have no moving parts and rely solely on forward speed for compression, making them unable to produce static thrust.
Project report on ammc's fabricated by friction stir processSelf-employed
The document discusses friction stir processing (FSP) which is a solid state technique used to modify the microstructure and mechanical properties of aluminium and its alloys. FSP is used to fabricate an aluminium metal matrix composite (AMMC) reinforced with nano Al2O3 particles. The objectives are to characterize the mechanical, structural and tribological properties of the fabricated AMMC. AA5083-H111 aluminium alloy will be processed using optimized FSP parameters such as tool design, rotational speed and transverse speed. The synthesized nano Al2O3 powder will be added to AA5083-H111 and stirred to produce the AMMC. Tests will then evaluate the microhardness, tensile strength
Cryogenic technology involves producing and studying materials and behaviors at very low temperatures below -150°C. It has various applications including rocket engines, power transmission, food storage, medical uses, sensors, and electronics. The presenter discusses the history and development of cryogenic technology, applications like its use in rocket engines, advantages like high energy density, limitations like low temperatures and leakages, and the future prospects of this field. India has independently developed cryogenic engine technology after initial difficulties in obtaining it from Russia in the 1990s.
Cryogenic rocket engines use liquid oxygen and hydrogen propellants which offer the highest energy efficiency for rockets requiring large thrust. The United States first developed these engines in the 1960s, while the Soviet Union did not succeed until 1987. India sought to import cryogenic engine technology in the 1990s but faced sanctions from the US and later Russia backed out of the deal. As a result, ISRO had to indigenously develop the technology which took 16 years to achieve success with the GSLV launch in 2010. Cryogenic engines provide clean, economical propulsion but also technical challenges like boil off and leakage of the extremely cold and reactive propellants.
Los Grupos de Apoyo y Orientación a Madres de todos los Orígenes ofrecen servicios a madres en situación de vulnerabilidad o riesgo de exclusión social en Cataluña. En 2016, atendieron a 6,235 madres directamente y 12,623 personas indirectamente a través de grupos de apoyo, detección de violencia doméstica, y acceso a servicios de salud, formación, vivienda y apoyo legal. Los fondos provinieron de agencias gubernamentales y se colaboró con hospitales y organizaciones para proporcionar una variedad
This document summarizes the cryogenic engine used for India's first geo-synchronous satellite launch vehicle. The engine used liquid oxygen and liquid hydrogen propellants, providing an high specific impulse of 450 seconds for improved efficiency. Key specifications of the cryogenic engine are provided such as its thrust rating, chamber pressure, nozzle area ratio, and mass. While cryogenic engines offer benefits like non-toxic propellants and high performance, they also pose challenges including the need for complex low-temperature storage and transfer systems as well as ignition challenges. The launch discussed ultimately failed, but future success is hoped for to help launch increasingly heavier satellites.
The document summarizes audience feedback collected at various stages of creating a professional music video. In the initial target audience survey, respondents indicated they enjoyed the crowd scenes and club-like venue. For the rough cut, over half said the video lacked narrative, prompting the filmmakers to add one. Feedback also influenced technical decisions and improved the website, digipak, and final products. The document shows how audience input helped guide and strengthen the project.
6.a fuzzy based sfcl for fault current limiter in distribution system (2)EditorJST
In the modern power system, as the utilization of electric power is very wide, and it is very easy for occurring any fault or disturbance, which causes a high short circuit current flows. More over the increase in the power generation results in an increase in the system fault current levels. The high current due to this fault large mechanical forces and these forces causes overheating of the equipment. If the large size equipment are used in power system then they need a large protection scheme from severe fault conditions. Generally, the maintaince of electrical power system reliability is more important. But the elimination of fault is not possible in power systems, so, the only alternate solution is to reduce the fault current levels. For this a fuzzy based Super Conducting Fault Current Limiter is the best electric equipment which is used for reducing the severe fault current levels. In this paper, we simulated the unsymmetrical faults with fuzzy based superconducting fault current limiter. In our analysis we had the following conclusions.
NASA SLS Cryogenic Engine - Complete ExplanationGokul Lakshmanan
The document discusses key aspects of NASA's Space Launch System (SLS) heavy-lift rocket. It describes the SLS core stage cryogenic engines, which use leftover Space Shuttle engines initially. It also covers construction details, rocket engine nozzle design principles, rocket engine cycles like staged combustion used by SLS, liquefying and storing cryogenic fuels, combustion zones in the thrust chamber, and regenerative cooling of engines using propellants.
Ammc's fabricated by friction stir processSelf-employed
The document discusses friction stir processing of aluminum metal matrix composites. It begins with an introduction to friction stir processing, describing how it uses a non-consumable tool to plastically deform metal and create a fine-grained microstructure without melting. The objectives and literature review on aluminum metal matrix composites are then summarized. Details are provided on the friction stir processing technique, selection of AA5083-H111 aluminum alloy, its properties and applications.
The document provides an evaluation of an FMP project involving a podcast. It summarizes the student's research, planning, time management, technical qualities, aural qualities, and audience appeal for the podcast product. It also includes feedback from peers, which suggested adding background music to the main audio recording to make it less dull. The student agreed that background music could improve the podcast based on the peer feedback.
The document discusses cryogenic rocket engines. It begins with an introduction to cryogenics and its uses, including for storing liquefied gases. It then discusses the history of cryogenics and its applications to rocket fuel and engines. Key points covered include:
- Cryogenic fuels like liquid oxygen and nitrogen are used in rocket engines.
- Cryogenic engines must keep fuel very cold to remain liquid inside the engine components and lines.
- Major components of cryogenic engines include the combustion chamber, fuel injectors, pumps, valves and tanks.
- The US, Russia, China, France, Japan and India have developed cryogenic rocket technology.
- Examples of cryogenic engines include those used in the Space Shut
Cryogenic engines use cryogenic fuels or oxidizers that are liquefied and stored at very low temperatures. They have high performance due to the rapid expansion of the liquid fuels to gas in the combustion chamber, producing thrust. Components are cooled to prevent boiling in the fuel lines. Some disadvantages are bulky cryogenic fuel tanks requiring heavy insulation, but their high fuel efficiency outweighs this. The Space Shuttle used cryogenic engines for lift-off. Key components include the combustion chamber, fuel injector, and rocket nozzle. Fuel and oxidizer are injected and mixed for combustion, producing hot exhaust gas that is accelerated through the nozzle to generate thrust.
Cryogenic rocket engines use cryogenic (very cold) liquid fuels like liquid hydrogen and liquid oxygen that are stored at extremely low temperatures. They provide several advantages like high energy density and clean, non-polluting exhaust but also have challenges like boil-off losses and material compatibility issues. The document outlines the history, construction, power cycles like gas-generator and pressure-fed, combustion process in the thrust chamber, and advantages and disadvantages of cryogenic rocket engines.
Cryogenics is the study of low temperatures and the production of low temperatures using liquefied gases like liquid nitrogen and liquid helium. Liquid rocket engines that use cryogenic fuels like liquid hydrogen and liquid oxygen provide some of the highest performance but also require bulky cryogenic fuel tanks and heavy insulation. There are two main types of liquid rocket engines - pressure-fed engines which use tank pressure to pump propellants and are simpler but provide lower performance, and pump-fed engines which use turbopumps to provide higher pressures and performance but are more complex. Cryogenic engines have been used successfully in applications like space shuttles and rockets where high performance outweighs the challenges of storing cryogenic fuels.
Cryogenic technology involves producing and working with extremely low temperatures below -150°C. It is used for rocket propellants like liquid oxygen and hydrogen, which must be kept cold to remain liquid and offer high energy efficiency for rocket engines. The United States developed the first cryogenic rocket engines in the 1960s. Cryogenic engines work by partially burning hydrogen with oxygen in a gas generator to power turbo pumps, then fully combusting the propellants in the thrust chamber to generate temperatures over 3,000°C and produce thrust by accelerating the propellants out of the nozzle. While cryogenic fuels provide high energy density and reduce fuel needs, their tanks require heavy insulation and the fuels tend to be bulky. Going forward, cry
This document summarizes an advanced rocket motors technical seminar. It discusses the principle of operation of rocket engines including components like propellant, combustion chamber, ignition system, and nozzle. It describes different types of rocket engines such as solid-propellant, liquid-propellant, and hybrid engines. Solid engines provide large thrust simply but cannot be throttled while liquid engines can be throttled and restarted but are more complex. Hybrid engines combine benefits of solid and liquid engines with a solid fuel and liquid oxidizer. The seminar discusses applications and advantages and disadvantages of each type.
Cryogenic rocket engines use liquid oxygen and liquid hydrogen propellants, which are cooled to extremely low temperatures below their freezing points. This allows them to be stored densely in rocket fuel tanks. The first operational cryogenic engine was developed by NASA in 1961. Cryogenic engines work by pumping the liquid propellants into a combustion chamber where they ignite and expand, producing thrust through a nozzle. They offer high energy efficiency but also technical challenges due to boil off and leakage risks at very low temperatures. Future rocket technologies may use alternative propulsion methods like ion engines or nuclear thermal rockets.
Cryogenic rocket engines use cryogenic, or very cold liquefied gases, as propellants. They are typically fueled by liquid hydrogen and liquid oxygen which must be stored at temperatures below -423°F and -297°F respectively to remain in liquid form. Cryogenic engines offer advantages like being able to control and restart the fuel flow, but require complex turbopumps and thermal insulation to handle the extreme cold temperatures. Major components include thrust chambers, fuel injectors, turbopumps, igniters, valves, tanks, and de Laval nozzles. The Space Shuttle's main engines were cryogenic, using this technology to produce high exhaust velocities and thrust.
Rocket engines produce thrust by accelerating and ejecting stored propellants at high speeds through a nozzle. They obtain high thrust-to-weight ratios but have the lowest fuel efficiency of all jet engines. Key components include the combustion chamber, where propellants combust at high pressures and temperatures, and the supersonic nozzle, which converts the hot gas energy into kinetic energy of the exhaust jet for propulsion. Rocket performance is optimized by maximizing exhaust velocity and specific impulse through high combustion temperatures, low-mass propellants, and nozzle designs that adapt to changing ambient pressures.
This document discusses cryogenic rocket engines. It begins with an introduction to cryogenics and cryogenic fuels that can be used for rocket engines. It then discusses the history of rocketry development by Russia and the US. Current rockets use liquid-fueled cryogenic engines, with the first being the RL10 in the 1960s. Cryogenic engines use supercooled liquid fuels like liquid oxygen and hydrogen that provide high energy density. Key components include the combustion chamber, injectors, pumps, valves and tanks. Cryogenic fuels allow for compact fuel storage on rockets. While powerful, cryogenic engines also present challenges like leakage and embrittlement issues. In conclusion, cryogenic rocketry is important for space exploration due to
1. Cryogenic rocket engines use liquid hydrogen at -253°C and liquid oxygen at -183°C as propellants, which must be kept at extremely low cryogenic temperatures to remain liquid.
2. These engines provide the highest efficiency of any rocket engine and have been used to launch many satellites.
3. Development of cryogenic engine technology started in the 1960s by countries including the US, Russia, Japan, France, and later India. Perfection of the technology proved challenging and took decades to master.
Cryogenics is the study of production and behavior of materials at very low temperatures below -150°C. Some important cryogenic fluids include liquid hydrogen, helium, oxygen, nitrogen and air. Key applications of cryogenics include rocket propulsion, magnetic resonance imaging, superconductivity, frozen food storage and more. Cryogenic technology enables efficient rocket engines using liquid hydrogen and oxygen propellants. India has developed its own cryogenic engine GSLV Mk III to launch satellites using this technology. Future prospects include more efficient ion engines and alternative nuclear or solar thermal rocket concepts.
Four-Stroke and Two-Stroke Marine Engines Comparison and ApplicationIJERA Editor
The document compares four-stroke and two-stroke marine engines. It provides details on the history and development of different marine engine types over time, from early propulsion relying on wind and oars to modern internal combustion engines. The four-stroke engine cycle includes intake, compression, power, and exhaust strokes within two revolutions of the crankshaft. The two-stroke engine completes the intake, compression, power, and exhaust steps within one revolution, making it more efficient but also risking exhaust of unburned fuel. Marine vessels favor two-stroke engines due to better fuel usage, efficiency, and power-to-weight ratio compared to four-stroke engines.
This document summarizes a seminar report on cryogenic rocket engines. It discusses how cryogenic rocket engines use liquid oxygen and hydrogen as fuel and oxidizer, which burn cleaner than hydrocarbon fuels. The report provides background on cryogenic technology, the history of cryogenic rocket engine development in the US and other countries in the 1960s. It describes the construction and working of cryogenic rocket engines, including components like the gas generator, turbo pumps, and thrust chamber. The report notes advantages of cryogenic fuels in providing high energy per unit mass and being clean-burning.
The document discusses the principles behind rocket engines and space exploration. It explains that rocket engines work by expelling mass at high speeds in one direction, which creates an equal and opposite reaction that propels the rocket in the other direction. It also describes the differences between solid and liquid fuel rockets, and how multi-stage rockets work by jettisoning empty stages to reduce mass and allow upper stages to accelerate the remaining rocket.
The document discusses the design and analysis of an engine for compressed air vehicles. It begins with an introduction to compressed air vehicles and how they work using stored compressed air instead of combustion. The engine design is modified from a typical 4-stroke internal combustion engine, with changes to the piston, cylinder, and camshaft to operate on compressed air. Experiments were conducted modifying a 100cc petrol engine to run on compressed air, achieving speeds up to 30kmph. The document outlines the basic operation of a 4-stroke engine and discusses modifications made to the camshaft profile to optimize the engine for compressed air. It also summarizes the results of other studies on compressed air engines and vehicles. Expected benefits are that compressed air vehicles would
This document discusses solid rocket propulsion. It describes the key components of a solid rocket motor, including the thermal insulation, nozzle, ignition system, and solid propellant grain. Solid propellant grains can be composite, containing an oxidizer like ammonium perchlorate and a fuel like aluminum powder held together by a binder. Performance criteria for rockets include thrust, specific impulse, total impulse, and effective exhaust velocity. Solid rockets provide high thrust but have low control and cannot easily be shut down or restarted.
This document discusses rocket propulsion and solid rocket motors. It defines propulsion as initiating or changing the motion of a body. Rocket propulsion works by ejecting propellant to create a reaction force and induce motion. Solid rocket motors use solid propellants composed of fuel, oxidizer, and binder. They provide high thrust but have low control and cannot be shut down and restarted. Performance is measured by parameters like specific impulse, total impulse, and effective exhaust velocity.
The document provides an introduction to compressed air engines. It discusses how compressed air engines store compressed air in tanks and use the expansion of the air to drive pistons, instead of fuel combustion. The document then reviews the history of compressed air vehicles from 1828 to the 1870s. It also describes the key components of compressed air engines, including compressors, air tanks, valves, pistons, connecting rods, and crankshafts. The crankshaft and camshaft components are explained in more detail.
This document summarizes testing of a 1,500 lbf thrust liquid oxygen/liquid methane rocket engine. The engine was developed through a collaboration between Armadillo Aerospace and NASA and tested at both sea level and simulated altitude conditions. Key findings included:
1) The engine was successfully ignited using both a gas torch and pyrotechnic igniter at sea level and vacuum.
2) Performance data was obtained for the engine using a dual-bell nozzle configuration at altitudes from 90,000 to 50,000 feet.
3) Armadillo Aerospace conducted the first tests of a self-pressurizing liquid oxygen/liquid methane propulsion system, eliminating the need for helium pressurization
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
2. Operations Strategy in a Global Environment.ppt
Cyogenic rocket engine report
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CONTENTS
1. Introduction
2. history
3. Space propulsion system
4. Classification of space propulsion system
5. Rocket engine power cycle
6. Combustion in thrust chamber
7. Fuel injection
8. Phase of combustion in thrust chamber
9. Different type of cryogenic engine
10. Conclusion
11. reference
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CHAPTER-1
INTRODUCTION
Cryogenics originated from two Greek words “kyros” which means cold or freezing and “genes”
which means born or produced. Cryogenics is the study of very low temperatures or the production
of the same. Liquefied gases like liquid nitrogen and liquid oxygen are used in many cryogenic
applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally
purchasable around the world. Liquid helium is also commonly used and allows for the lowest
temperatures to be reached. These gases can be stored on large tanks called Dewar tanks, named
after James Dewar, who first liquefied hydrogen, or in giant tanks used for commercial applications.
The field of cryogenics advanced when during world war two, when metals were frozen to
low temperatures showed more wear resistance. In 1966, a company was formed, called Cyro-Tech,
which experimented with the possibility of using cryogenic tempering instead of Heat Treating, for
increasing the life of metal tools. The theory was based on the existing theory of heat treating, which
was lowering the temperatures to room temperatures from high temperatures and supposing that
further descent would allow more strength for further strength increase. Unfortunately for the newly-
born industry the results were unstable as the components sometimes experienced thermal shock
when cooled too fast. Luckily with the use of applied research and the with the arrival of the modern
computer this field has improved significantly, creating more stable results.
Another use of cryogenics is cryogenic fuels. Cryogenic fuels, mainly oxygen and nitrogen have
been used as rocket fuels. The Indian Space Research Organization (ISRO) is set to flight-test the
indigenously developed cryogenic engine by early 2006, after the engine passed a 1000 second
endurance test in 2003. It will form the final stage of the GSLV for putting it into orbit 36,000 km from
earth.
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Cryogenic Engines are rocket motors designed for liquid fuels that have to be held at very low
"cryogenic" temperatures to be liquid - they would otherwise be gas at normal temperatures.
The engine components are also cooled so the fuel doesn't boil to a gas in the lines that
feed the engine. The thrust comes from the rapid expansion from liquid to gas with the gas
emerging from the motor at very high speed. The energy needed to heat the fuels comes from
burning them, once they are gasses. Cryogenic engines are the highest performing rocket motors.
One disadvantage is that the fuel tanks tend to be bulky and require heavy insulation to store the
propellant. Their high fuel efficiency, however, outweighs this disadvantage.
The Space Shuttle's main engines used for liftoff are cryogenic engines. The Shuttle's
smaller thrusters for orbital maneuvering use non-cryogenic hypergolic fuels, which are compact
and are stored at warm temperatures. Currently, only the United States, Russia, China, France,
Japan and India have mastered cryogenic rocket technology.
All the current Rockets run on Liquid-propellant rockets. The first operational cryogenic rocket
engine was the 1961 NASA design the RL-10 LOX LH2 rocket engine, which was used in the Saturn
1 rocket employed in the early stages of the Apollo moon landing program.
The major components of a cryogenic rocket engine are:
• the thrust chamber or combustion chamber
• pyrotechnic igniter
• fuel injector
• fuel turbo-pumps
• gas turbine
• cryo valves
• Regulators
• The fuel tanks
• rocket engine
• nozzle
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Among them, the combustion chamber & the nozzle are the main components of the rocket
engine.
CHAPTER-2
HISTORY
The only known claim to liquid propellant rocket engine experiments in the nineteenth century
was made by a Peruvian scientist named Pedro Paulet. However, he did not immediately publish
his work. In 1927 he wrote a letter to a newspaper in Lima, claiming he had experimented with a
liquid rocket engine while he was a student in Paris three decades earlier.
Historians of early rocketry experiments, among them Max Valier and Willy Ley, have given
differing amounts of credence to Paulet's report. Paulet described laboratory tests of liquid rocket
engines, but did not claim to have flown a liquid rocket.
The first flight of a vehicle powered by a liquid-rocket took place on March 16, 1926 at Auburn,
Massachusetts, when American professor Robert H. Goddard launched a rocket which used liquid
oxygen and gasoline as propellants. The rocket, which was dubbed "Nell", rose just 41 feet during
a 2.5-second flight that ended in a cabbage field, but it was an important demonstration that liquid
rockets were possible.
CHAPTER-3
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SPACE PROPULSION SYSTEM
Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites.
There are many different methods. Each method has drawbacks and advantages, and spacecraft
propulsion is an active area of research. However, most spacecraft today are propelled by forcing a
gas from the back/rear of the vehicle at very high speed through a supersonic de Laval nozzle. This
sort of engine is called a rocket engine.
All current spacecraft use chemical rockets (bipropellant or solid-fuel) for launch, though
some have used air-breathing engines on their first stage. Most satellites have simple reliable
chemical thrusters. Soviet bloc satellites have used electric propulsion for decades, and newer
Western geo-orbiting spacecraft are starting to use them for north-south station keeping.
Interplanetary vehicles mostly use chemical rockets as well, although a few have used ion thrusters
to great success.
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CHAPTER-4
Classification of Space Propulsion System
CHAPTER-5
ROCKET ENGINE POWER CYCLE
Gas pressure feed system
A simple pressurized feed system is shown schematically below. It consists of a high-
pressure gas tank, a gas starting valve, a pressure regulator, propellant tanks, propellant valves,
and feed lines. Additional components, such as filling and draining provisions, check valves, filters,
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flexible elastic bladders for separating the liquid from the pressurizing gas, and pressure sensors or
gauges, are also often incorporated. After all tanks are filled, the high-pressure gas valve is remotely
actuated and admits gas through the pressure regulator at a constant pressure to the propellant
tanks. The check valves prevent mixing of the oxidizer with the fuel when the unit is not in an right
position. The propellants are fed to the thrust chamber by opening valves. When the propellants are
completely consumed, the pressurizing gas can also scavenge and clean lines and valves of much
of the liquid propellant residue. The variations in this system, such as the combination of several
valves into one or the elimination and addition of certain components, depend to a large extent on
the application. If a unit is to be used over and over, such as space-maneuver rocket, it will include
several additional features such as, possibly, a thrust-regulating device and a tank level gauge.
Gas-Generator Cycle
The gas-generator cycle taps off a small amount of fuel and oxidizer from the main flow to feed a
burner called a gas generator. The hot gas from this generator passes through a turbine to generate
power for the pumps that send propellants to the combustion chamber. The hot gas is then either
dumped overboard or sent into the main nozzle downstream. Increasing the flow of propellants into
the gas generator increases the speed of the turbine, which increases the flow of propellants into
the main combustion chamber (and hence, the amount of thrust produced). The gas generator must
burn propellants at a less-than-optimal mixture ratio to keep the temperature low for the turbine
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blades. Thus, the cycle is appropriate for moderate power requirements but not high-power systems,
which would have to divert a large portion of the main flow to the less efficient gas-generator flow.
Staged Combustion Cycle
In a staged combustion cycle, the propellants are burned in stages. Like the gasgenerator
cycle, this cycle also has a burner, called a preburner, to generate gas for a turbine. The pre-burner
taps off and burn a small amount of one propellant and a large amount of the other, producing an
oxidizer-rich or fuel-rich hot gas mixture that is mostly unburned vaporized propellant. This hot gas
is then passed through the turbine, injected into the main chamber, and burned again with the
remaining propellants. The advantage over the gas-generator cycle is that all of the propellants are
burned at the optimal mixture ratio in the main chamber and no flow is dumped overboard. The
staged combustion cycle is often used for high-power applications. The higher the chamber
pressure, the smaller and lighter the engine can be to produce the same thrust. Development cost
for this cycle is higher because the high pressures complicate the development process.
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CHAPTER-6
COMBUSTION IN THRUST CHAMBER
The thrust chamber is the key subassembly of a rocket engine. Here the liquid propellants
are metered, injected, atomized, vaporized, mixed, and burned to form hot reaction gas products,
which in turn are accelerated and ejected at high velocity. A rocket thrust chamber assembly has an
injector, a combustion chamber, a supersonic nozzle, and mounting provisions. All have to withstand
the extreme heat of combustion and the various forces, including the transmission of the thrust force
to the vehicle.
There also is an ignition system if non-spontaneously ignitable propellants are used.
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FUEL INJECTION
The functions of the injector are similar to those of a carburetor of an internal combustion
engine. The injector has to introduce and meter the flow of liquid propellants to the combustion
chamber, cause the liquids to be broken up into small droplets (a process called atomization), and
distribute and mix the propellants in such a manner that a correctly proportioned mixture of fuel and
oxidizer will result, with uniform propellant mass flow and composition over the chamber cross
section. This has been accomplished with different types of injector designs and elements.
The injection hole pattern on the face of the injector is closely related to the internal manifolds
or feed passages within the injector. These provide for the distribution of the propellant from the
injector inlet to all the injection holes. A large complex manifold volume allows low passage velocities
and good distribution of flow over the cross section of the chamber. A small manifold volume allows
for a lighter weight injector and reduces the amount of "dribble" flow after the main valves are shut.
The higher passage velocities cause a more uneven flow through different identical injection holes
and thus a poorer distribution and wider local gas composition variation.
Dribbling results in afterburning, which is an inefficient irregular combustion that gives a little "cutoff"
thrust after valve closing. For applications with very accurate terminal vehicle velocity requirements,
the cutoff impulse has to be very small and reproducible and often valves are built into the injector
to minimize passage volume. Impinging-stream-type, multiple-hole injectors are commonly used
with oxygenhydrocarbon and storable propellants. For unlike doublet patterns the propellants are
injected through a number of separate small holes in such a manner that the fuel and oxidizer
streams impinge upon each other. Impingement forms thin liquid fans and aids atomization of the
liquids into droplets, also aiding distribution. The two liquid streams then form a fan which breaks up
into droplets.
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Unlike doublets work best when the hole size (more exactly, the volume flow) of
the fuel is about equal to that of the oxidizer and the ignition delay is long enough to allow
the formation of fans. For uneven volume flow the triplet pattern seems to be more
effective.
The non-impinging or shower head injector employs non-impinging streams of
propellant usually emerging normal to the face of the injector. It relies on turbulence and
diffusion to achieve mixing. The German World War II V-2 rocket used this type of injector.
This type is now not used, because it requires a large chamber volume for good
combustion.
Sheet or spray-type injectors give cylindrical, conical, or other types of spray
sheets; these sprays generally intersect and thereby promote mixing and atomization. By
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varying the width of the sheet (through an axially moveable sleeve) it is possible to throttle
the propellant flow over a wide range without excessive reduction in injector pressure
drop. This type of variable area concentric tube injector was used on the descent engine
of the Lunar Excursion Module and throttled over a 10:1 range of flow with only a very
small change in mixture ratio.
The coaxial hollow post injector has been used for liquid oxygen and gaseous hydrogen
injectors by most domestic and foreign rocket designers. It works well when the liquid
hydrogen has absorbed heat from cooling jackets and has been gasified. This gasified
hydrogen flows at high speed (typically 330 m/sec or 1000 ft/sec); the liquid oxygen flows
far more slowly (usually at less than 33 m/sec or 100 ft/sec) and the differential velocity
causes a shear action, which helps to break up the oxygen stream into small droplets.
The injector has a multiplicity of these coaxial posts on its face.
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CHAPTER-8
PHASES OF COMBUSTION IN THRUST CHAMBER
Rapid Combustion Zone
In this zone intensive and rapid chemical reactions occur at increasingly higher
temperature; any remaining liquid droplets are vaporized by convective heating and gas
pockets of fuel-rich and fuel-lean gases are mixed. The mixing is aidedby local turbulence
and diffusion of the gas species. The further breakdown of the propellant chemicals into
intermediate fractions and smaller, simpler chemicals and the oxidation of fuel fractions
occur rapidly in this zone. The rate of heat release increases greatly and this causes the
specific volume of the gas mixture to increase and the local axial velocity to increase by
a factor of 100 or more.
The rapid expansion of the heated gases also forces a series of local transverse
gas flows from hot high-burning-rate sites to colder low-burning-rate sites. The liquid
droplets that may still persist in the upstream portion of this zone do not follow the gas
flow quickly and are difficult to move in a transverse direction. Therefore, zones of fuelrich
or oxidizer-rich gases will persist according to the orifice spray pattern in the upstream
injection zone. The gas composition and mixture ratio across the chamber section
become more uniform as the gases move through this zone, but the mixture never
becomes truly uniform.
As the reaction product gases are accelerated, they become hotter (due to further
heat releases) and the lateral velocities become relatively small compared to the
increasing axial velocities. The combustion process is not a steady flow process. Some
people believe that the combustion is locally so intense that it approches localized
explosions that create a series of shock waves. When observing any one specific location
in the chamber, one finds that there are rapid fluctuations in pressure, temperature,
density, mixture ratio, and radiation emissions with time.
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Injection/Atomization Zone
Two different liquids are injected with storable propellants and with liquid
oxygen/hydrocarbon combinations. They are injected through orifices at velocities
typically between 7 and 60 m/sec or about 20 to 200 ft/sec. The injector design has a
profound influence on the combustion behavior and some seemingly minor design
changes can have a major effect on instability. The pattern, sizes, number, distribution,
and types of orifices influence the combustion behavior, as do the pressure drop, manifold
geometry, or surface roughness in the injection orifice walls.
The individual jets, streams, or sheets break up into droplets by impingement of
one jet with another (or with a surface), by the inherent instabilities of liquid sprays, or by
the interaction with gases at a different velocity and temperature. In this first zone the
liquids are atomized into a large number of small droplets. Heat is transferred to the
droplets by radiation from the very hot rapid combustion zone and by convection from
moderately hot gases in the first zone. The droplets evaporate and create local regions
rich either in fuel vapor or oxidizer vapor.
This first zone is heterogeneous; it contains liquids and vaporized propellant as
well as some burning hot gases. With the liquid being located at discrete sites, there are
large gradients in all directions with respect to fuel and oxidizer mass fluxes, mixture ratio,
size and dispersion of droplets, or properties of the gaseous medium. Chemical reactions
occur in this zone, but the rate of heat generation is relatively low, in part because the
liquids and the gases are still relatively cold and in part because vaporization near the
droplets causes fuel-rich and fuel-lean regions which do not burn as quickly. Some hot
gases from the combustion zone are re-circulated back from the rapid combustion zone,
and they can create local gas velocities that flow across the injector face.
The hot gases, which can flow in unsteady vortexes or turbulence patterns, are
essential to the initial evaporation of the liquids. The injection, atomization and
vaporization processes are different if one of the propellants is a gas. For example, this
occurs in liquid oxygen with gaseous hydrogen propellant in thrust chambers or
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precombustion chambers, where liquid hydrogen has absorbed heat from cooling jackets
and has been gasified. Hydrogen gas has no droplets and does not evaporate. The gas
usually has a much higher injection velocity (above 120 m/sec) than the liquid propellant.
This cause shear forces to be imposed on the liquid jets, with more rapid droplet
formation and gasification. The preferred injector design for gaseous hydrogen and liquid
oxygen is different from the individual jet streams used with storable propellants.
Stream Tube Combustion Zone
In this zone oxidation reactions continue, but at a lower rate, and some additional
heat is released. However, chemical reactions continue because the mixture tends to be
driven toward an equilibrium composition. Since axial velocities are high (200 to 600
m/sec) the transverse convective flow velocities become relatively small. Streamlines are
formed and there is relatively little turbulent mixing across streamline boundaries. Locally
the flow velocity and the pressure fluctuate somewhat. The residence time in this zone is
very short compared to the residence time in the other two zones. The streamline type,
inviscid flow, and the chemical reactions toward achieving chemical equilibrium persist
not only throughout the remainder of the combustion chamber, but are also extended into
the nozzle. Actually, the major processes do not take place strictly sequentially, but
several seem to occur simultaneously in several parts of the chamber. The flame front is
not a simple plane surface across the combustion chamber
There is turbulence in the gas flow in all parts of the combustion chamber. The
residence time of the propellant material in the combustion chamber is very short, usually
less than 10 milliseconds. Combustion in a liquid rocket engine is very dynamic, with the
volumetric heat release being approximately 370 MJ/m3-sec, which is much higher than
in turbojets. Further, the higher temperature in a rocket causes chemical reaction rates to
be several times faster (increasing exponentially with temperature) than in turbojet.
The four phases of combustion in the thrust chamber are
1. Primary Ignition
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2. Flame Propagation
3. Flame Lift off
4. Flame Anchoring
Primary Ignition
begins at the time of deposition of the energy into the shear layer and ends when
the flame front has reached the outer limit of the shear layer starts interaction
with the recirculation zone.
phase typically lasts about half a millisecond
it is characterised by a slight but distinct downstream movement of the flame .
The flame velocity more or less depends on the pre-mixedness of the shear layer
only.
Flame Propagation
This phase corresponds to the time span for the flame reaching the edge of the
shear layer, expands into in the recirculation zone and propagates until it has
consumed all the premixed propellants.
This period lasts between 0.1 and 2 ms.
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It is characterised by an upstream movement of the upstream flame front until it
reaches a minimum distance from the injector face plate.
It is accompanied by a strong rise of the flame intensity and by a peak in the
combustion chamber pressure.
The duration of this phase as well as the pressure and emission behaviour during
this phase depend strongly on the global characteristics of the stationary cold flow
before ignition.
Flame Lift Off
phase starts when the upstream flame front begins to move downstream away
from the injector because all premixed propellants in the recirculation zone have
been consumed until it reaches a maximum distance.
This period lasts between 1 and 5 ms.
The emission of the flame is less intense showing that the chemical activity has
decreased.
The position where the movement of the upstream flame front comes to an end,
the characteristic times of convection and flame propagation are balanced.
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Flame Anchoring.
This period lasts from 20 ms to more than 50 ms, depending on the injection
condition.
It begins when the flame starts to move a second time upstream to injector face
plate and ends when the flame has reached stationary conditions.
During this phase the flame propagates upstream only in the shear layer .
Same as flame lift-off phase the vaporisation is enhanced by the hot products
which are entrained into the shear layer through the recirculation zone.
The flame is stabilised at a position where an equilibrium exists between the local
velocity of the flame front and the convective flow velocity.
This local flame velocity is depending on the upstream LOX-evaporation rates,
i.e., the available gaseous O2, mixing of O2 and H2, hot products and radicals in
the shear layer.
At the end of this phase, combustion chamber pressure and emission intensity are
constant.
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CHAPTER-9
DIFFERENT TYPES OF CRYOGENIC ENGINES
HM-7B Rocket Engine
HM-7 cryogenic propellant rocket engine has been used as an upper stage engine
on all versions of the Ariane launcher. The more powerful HM-7B version was used on
Ariane's 2, 3 and 4 and is also used on the ESC-A cryogenic upper stage of Ariane 5.
Important principles used in the HM-7 combustion chamber were adopted by NASA under
license and it is this technology that formed the basis of today's US space shuttle main
engines - the first reusable rocket engine in the world.
The HM7 engine was built upon the development work of the 40kN HM-4 engine.
In 1973, the Ottobrunn team started development of the HM-7 thrust chamber for the third
stage of Ariane 1. Six years later, the HM-7 engine was successfully qualified with the
first launch of Ariane 1 in December 1979.
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With the introduction of Ariane 2 and Ariane 3, it became necessary to increase
the performance of the HM-7 engine. This was achieved by raising the combustion
chamber pressure from 30 to 35 bar and extending the nozzle, thereby raising the specific
impulse. The burn time was also increased from 570 to 735 seconds. The upgraded
engine was thus designated HM-7B and was qualified in 1983. When subsequently used
on Ariane 4, the burn time was increased to 780 seconds.
In February 2005, the HM-7B successfully powered the new cryogenic upper stage
of Ariane 5, designate ESC-A (Etage Superior Cryo-technique A). This flight was a tribute
to the performance and flight proven reliability of an engine first developed 30 years ago.
With the ESC-A upper stage, the payload performance of Ariane 5 is increased to 10
tonnes. In order to inherit the proven reliability of the HM-7B engine from over one
hundred Ariane 4 flights, engine changes were kept to a minimum. The main change
being a 20% increase in burn time from 780 seconds to 950 seconds on Ariane 5 ESC-
A.
Use of HM-7B on Ariane 5 is a first step toward increasing the payload
performance of Ariane 5. A second step will be the introduction of the new Vinci expander
cycle engine to an ESC-B cryogenic upper stage, increasing the payload performance to
12 tonnes
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The HM7B engine is a gas generator liquid oxygen / liquid hydrogen engine that
powers the Ariane 4 third stage. The HM7 engine built upon the development work of the
40 kN thrust HM4. The HM7 development program began in 1973 as part of Europe's
effort to develop an indigenous launch capability. Final qualification of the
HM7 engine occurred in 1979 and the engine went on to power the third stage of the
Ariane 1. SEP continued to perfect and upgrade the engine, increasing the specific
impulse by 4 seconds by increasing chamber pressure and lengthening the nozzle. The
new engine, the HM7B, powered the third stage of the Ariane 2,3 and 4. As of June 1st,
1995, SEP had produced 111 HM7B engines, with a cumulated total of 171,700 seconds
of operation, including 47,400 in flight.
300 N Cryogenic Engine:
This 300 N cryogenic propellant engine has a vacuum Isp of 415 seconds - the
highest value ever achieved in Europe for an engine of such small size.
Being pressure-fed, the engine assembly is relatively simple and avoids the need
for a turbo-pump. The thrust chamber and throat region of the engine are regenerative
cooled using hydrogen propellant. The nozzle extension is radiation cooled.
The engine incorporates a splash-plate injector having a star shaped configuration.
Ignition and subsequent re-ignition is achieved using Tri-ethyl aluminum (TEA) - which is
hypergolic with the oxygen propellant. The number of re-ignitions is a function of the
volume of Tri-ethyl aluminum accommodated. The engine nominally provides for 1
ignition and 3 re-ignitions using just 1.5 cc of Tri-ethyl aluminum. The use of a chemical
ignition system enables a very compact design.
The engine needs no pre-cooling prior to ignition. Only the propellant feed lines to
the engine propellant valves need be pre-cooled.
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Engine construction materials are mainly stainless steel, Nimonic 75
(ChromiumNickel Alloy) and copper.
Applications
The 300 N cryogenic engines enable the simplicity of a pressure fed propulsion
system whilst offering the performance of a turbo-pump propulsion system.
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Being pressure fed, the engine does not require an additional turbo-pump, with
its associated complexity.
The 300 N cryogenic engines may be used as a main engine in dedicated stages
for orbital insertion, orbital transfer, orbital, and interplanetary applications, including:
Upper stages
Kick stages
Vernier stages
Transfer stages
The 300 N cryogenic engines may also be used as a thruster, or thruster cluster with
existing cryogenic turbo-pump propulsion systems and stages for such applications as
performance augmentation, upgrades, roll control.
Vulcain Rocket Engine
Vulcain (also known as HM-60) was the first main engine of the Ariane 5 cryogenic
first stage (EPC). The development of Vulcain, assured by a European collaboration,
began in 1988 with the Ariane 5 rocket program. It first flew in 1996 powering the ill-fated
flight 501 without being the cause of the disaster, and had its first successful flight in 1997
(flight 502). In 2002 the upgraded Vulcain 2 with 20% more thrust first flew on flight 517,
although a problem with the engine turned the flight into a failure. The cause was due to
flight loads being much higher than expected, as the inquiry board concluded.
Subsequently, the nozzle has been redesigned, reinforcing the structure and
improving the thermal situation of the tube wall, enhancing hydrogen coolant flow as well
as applying thermal barrier coating to the flame-facing side of the coolant tubes, reducing
heat load. The first successful flight of the (partially redesigned) Vulcain 2 occurred in
2005 on flight 521. The Vulcain engines are gas-generator cycle cryogenic rocket engines
fed with liquid oxygen and liquid hydrogen.
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They feature regenerative cooling through a tube wall design, and the Vulcain 2
introduced a particular film cooling for the lower part of the nozzle, where exhaust gas
from the turbine is re-injected in the engine They power the first stage of the Ariane 5
launcher, the EPC (Étage Principal Cryo technique, main cryogenic stage) and provide
8% of the total lift-off thrust (the rest being provided by the two solid rocket boosters).
The engine operating time is 600 s in both configurations.
The coaxial injector elements cause the LOX and LH2 propellants to be mixed
together. LOX is injected at the centre of the injector, around which the LH2 is injected.
These propellants are mainly atomized and mixed by shear forces generated by the
velocity differences between LOX and LH2. The final acceleration of hot gases, up to
supersonic velocities, is achieved by gas expansion in the nozzle extension, thereby
increasing the thrust.
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Applications:
• main engine of the Ariane 5 cryogenic first stage
(EPC)
VINCI Rocket Engine:
Vinci is a European Space Agency cryogenic rocket engine currently under
development. It is designed to power the new upper stage of Ariane 5, ESC-B, and will
be the first European re-ignitable cryogenic upper stage engine, raising the launcher's
GTO performances to 12 t. Vinci is an expander cycle rocket engine fed with liquid
hydrogen and liquid oxygen. Its biggest improvement from its predecessor, the HM-7 is
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the capability of restarting up to five times. It is also the first European expander cycle
engine, removing the need for a gas generator to drive the fuel and oxydizer pumps. It
features a carbon ceramic extendable nozzle in order to have a large, 2.15 m diameter
nozzle extension with minimum length: the retracted nozzle part is deployed only after
the upper stage separates from the rest of the rocket; after extension, the engine's overall
length increases from 2.3 m to 4.2 m.
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Applications:
• upper stage of Ariane 5
CHAPTER-10
CONCLUSION
The area of Cryogenics in Cryogenic Rocket Engines is a vast one and it cannot
be described in a few words. As the world progress new developments are being made
more and more new developments are being made in the field of Rocket Engineering.
Now a day cryo propelled rocket engines are having a great demand in the field of space
exploration. Due to the high specific impulse obtained during the ignition of fuels they are
of much demand.
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CHAPTER-11
REFERENCES
“Rocket propulsion elements” by G. P. Sutton, 7th edition.
“Advances in propulsion” by K. Ramamurthy.
“Rocket and Spacecraft Propulsion” by M. J. Turner.
“Ignition of cryogenic H2/LOX sprays” by O. Gurliat, V. Schmidt, O.J. Haidn, M.
Oschwald.
National Aeronautics and Space Administration, United States Of America
Vikram Sarabhai Space Centre, Thiruvananthapuram