This document summarizes numerical modeling and simulation results pertaining to high-speed combustion in scramjets from various researchers. It reviews work using large eddy simulation to model supersonic reacting flows, addressing issues like turbulence modeling. It also summarizes simulations using LES with subgrid eddy mixing and combustion models that showed good agreement with experimental data. Further, it discusses LES studies of hydrogen-fueled scramjet combustion incorporating finite-rate chemistry models.
Numerical Modelling of Trans-Triple Point Temperature Near-Field Sonic Dispersion of CO2 from High Pressure Dense Phase Pipelines, Chris Wareing, University of Leeds. Presented at CO2 Properties and EoS for Pipeline Engineering, 11th November 2014
The document discusses a study using computational fluid dynamics (CFD) and temperature sensitive paint (TSP) to analyze the aerothermodynamic response of three hypersonic vehicle geometries - the Reference Flight System model G (RFSG), a Generic Hypersonic Vehicle (GHV), and the Hypersonic International Flight Research Experimentation Program-Flight 1 (HIFiRE-1) payload geometry. The study aims to validate the aero-thermal capabilities of the Mach 6 wind tunnel at Wright-Patterson Air Force Base by comparing TSP temperature distributions from wind tunnel tests to results from the CFD codes CBAero and UNLATCH. Preliminary TSP temperature distributions for the HIFiRE
The document summarizes a lab experiment that tested the efficiency of parallel and counter-flow heat exchangers. Equations were developed to calculate efficiency based on inlet and outlet temperatures and flow rates. The results showed that parallel flow had higher efficiency values than counter-flow, with efficiencies ranging from 22-56% for parallel flow and 4-13% for counter-flow. The higher efficiency of parallel flow was due to its larger temperature differences and faster mass flow rates.
This presentation investigates the hypersonic high enthalpy flow in a leading edge configuration using computational techniques, specifically using computational fluid dynamics.
Flow separation in/over a hypersonic space vehicle is an important phenomenon which occurs due to flow interaction with various geometric elements of the vehicle. This however can lead to adverse pressure gradient and localised intense heating resulting in detrimental consequences for the successful performance of the vehicle. It is therefore critical and necessary to understand the separation phenomenon and its characteristics. In the last several decades, experimental, analytical and computational techniques have been used to investigate flow separation in hypersonic flow. Despite these efforts, large gaps still remain in our understanding of the aerothermodynamics of flow separation. Typically, flow separation can be examined with simple geometric configurations representing a generic region of separated flow over a vehicle. These could range from geometries such as compression corners, flat plate with steps to blunt bodies such as cylinders and spheres. However, most of these configurations exhibit a pre-existing boundary layer prior to separation thus increasing the complexity of the interaction. A simple geometry capable of producing separation at the leading-edge without any pre-existing boundary layer is therefore considered here. This geometry was originally proposed by Chapman in 1958 for supersonic flows at high Reynolds numbers and is investigated here numerically under laminar low density hypersonic conditions using N-S and DSMC methods.
This document describes a thesis analyzing natural convection in a vertical microchannel using computational fluid dynamics (CFD). The thesis examines:
1) Fully developed flow conditions in a vertical parallel-plate microchannel with asymmetric wall temperatures, considering both velocity slip and temperature jump at the walls.
2) A more general approach to analyze entrance region conditions, without assumptions of fully developed flow.
3) Governing equations of continuity, momentum and energy to model the natural convection problem using the boundary layer approximations.
This document is an unofficial academic record for John M. Harris from Texas A&M University. It shows that he is pursuing a Bachelor of Science in Chemical Engineering with a minor in Mathematics. It lists the courses he has taken and transferred in from other institutions, along with the grades and credits. His overall GPA is 3.579 based on 247 quality points earned from 69 GPA hours at Texas A&M. He is currently enrolled in 4 courses for the Spring 2017 semester.
Numerical Modelling of Trans-Triple Point Temperature Near-Field Sonic Dispersion of CO2 from High Pressure Dense Phase Pipelines, Chris Wareing, University of Leeds. Presented at CO2 Properties and EoS for Pipeline Engineering, 11th November 2014
The document discusses a study using computational fluid dynamics (CFD) and temperature sensitive paint (TSP) to analyze the aerothermodynamic response of three hypersonic vehicle geometries - the Reference Flight System model G (RFSG), a Generic Hypersonic Vehicle (GHV), and the Hypersonic International Flight Research Experimentation Program-Flight 1 (HIFiRE-1) payload geometry. The study aims to validate the aero-thermal capabilities of the Mach 6 wind tunnel at Wright-Patterson Air Force Base by comparing TSP temperature distributions from wind tunnel tests to results from the CFD codes CBAero and UNLATCH. Preliminary TSP temperature distributions for the HIFiRE
The document summarizes a lab experiment that tested the efficiency of parallel and counter-flow heat exchangers. Equations were developed to calculate efficiency based on inlet and outlet temperatures and flow rates. The results showed that parallel flow had higher efficiency values than counter-flow, with efficiencies ranging from 22-56% for parallel flow and 4-13% for counter-flow. The higher efficiency of parallel flow was due to its larger temperature differences and faster mass flow rates.
This presentation investigates the hypersonic high enthalpy flow in a leading edge configuration using computational techniques, specifically using computational fluid dynamics.
Flow separation in/over a hypersonic space vehicle is an important phenomenon which occurs due to flow interaction with various geometric elements of the vehicle. This however can lead to adverse pressure gradient and localised intense heating resulting in detrimental consequences for the successful performance of the vehicle. It is therefore critical and necessary to understand the separation phenomenon and its characteristics. In the last several decades, experimental, analytical and computational techniques have been used to investigate flow separation in hypersonic flow. Despite these efforts, large gaps still remain in our understanding of the aerothermodynamics of flow separation. Typically, flow separation can be examined with simple geometric configurations representing a generic region of separated flow over a vehicle. These could range from geometries such as compression corners, flat plate with steps to blunt bodies such as cylinders and spheres. However, most of these configurations exhibit a pre-existing boundary layer prior to separation thus increasing the complexity of the interaction. A simple geometry capable of producing separation at the leading-edge without any pre-existing boundary layer is therefore considered here. This geometry was originally proposed by Chapman in 1958 for supersonic flows at high Reynolds numbers and is investigated here numerically under laminar low density hypersonic conditions using N-S and DSMC methods.
This document describes a thesis analyzing natural convection in a vertical microchannel using computational fluid dynamics (CFD). The thesis examines:
1) Fully developed flow conditions in a vertical parallel-plate microchannel with asymmetric wall temperatures, considering both velocity slip and temperature jump at the walls.
2) A more general approach to analyze entrance region conditions, without assumptions of fully developed flow.
3) Governing equations of continuity, momentum and energy to model the natural convection problem using the boundary layer approximations.
This document is an unofficial academic record for John M. Harris from Texas A&M University. It shows that he is pursuing a Bachelor of Science in Chemical Engineering with a minor in Mathematics. It lists the courses he has taken and transferred in from other institutions, along with the grades and credits. His overall GPA is 3.579 based on 247 quality points earned from 69 GPA hours at Texas A&M. He is currently enrolled in 4 courses for the Spring 2017 semester.
A Novel Technique in Software Engineering for Building Scalable Large Paralle...Eswar Publications
Parallel processing is the only alternative for meeting computational demand of scientific and technological advancement. Yet first few parallelized versions of a large application code- in the present case-a meteorological Global Circulation Model- are not usually optimal or efficient. Large size and complexity of the code cause making changes for efficient parallelization and further validation difficult. The paper presents some novel techniques to enable change of parallelization strategy keeping the correctness of the code under control throughout the modification.
On assessing the accuracy of offshore wind turbine reliability based designabelkrusnik02
This document discusses assessing the accuracy of design loads derived using the environmental contour method for offshore wind turbines. It compares design loads from this method to exact solutions using full integration over the failure domain. The environmental contour method makes two key assumptions that are often violated: 1) the limit state surface is well approximated by a tangent hyperplane at the design point, and 2) only a single failure mode is considered. This can introduce errors since wind turbine failure can occur under different operating conditions. The document examines these sources of error using an offshore wind turbine located at two Danish sites, Rødsand and Horns Rev, and their differing environmental conditions.
Consequence assessment methods for incidents from lngaob
This document summarizes methods for assessing consequences of incidents involving releases from liquefied natural gas carriers. It recommends using an orifice model to estimate release rates, Webber's methodology to model pool spreading accounting for frictional forces, and heat transfer theory to calculate heat flux to boiling pools. For fires, it recommends using a solid flame model. It also provides injury and damage criteria for assessing impacts to people and structures from thermal radiation. The document notes limitations in current models and calls for additional research, particularly spill tests, to improve accuracy.
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Ten most popular software for prediction of cyclonic stormsMrinmoy Majumder
In recent years the frequency and intensity of cyclones and hurricanes have been increased manifold compared to the last decade. As a result, the necessity for the development of computer models to predict the track, intensity, and time of occurrence of cyclonic storms has increased to avoid loss of life and prevention of damages to public properties. In this presentaion I had tried to highlight the ten most used models in this aspect which are responsible for saving millions of life and their livelihood.
Combustion and Mixing Analysis of a Scramjet Combustor Using CFDijsrd.com
This document summarizes a computational fluid dynamics (CFD) study of combustion and mixing in a scramjet combustor. The study uses ANSYS Fluent software to model flow inside a scramjet combustor geometry for hydrogen, diesel, and methane fuels. The objectives are to determine the flow field and maximize thrust at a Mach number of 2. Key findings include that combustion increases recirculation behind the flameholder strut compared to mixing alone, and shockwaves from the strut facilitate combustion ignition in regions with fuel-air mixing. Meshing of the combustor geometry and strut are discussed.
Comparison of Two Dispersion Models_A Bulk Petroleum Storage Terminal Case St...BREEZE Software
"This study presents a comparison of the pollutant concentration predictions from the
AERMOD and ISC air dispersion models in the context of
fugitive storage tank emissions at a bulk petroleum storage terminal."
Aerodynamic Analysis of the Liebeck L2573 High-Lift AirfoilTodd Ramsey
The document analyzes the L2573 high-lift airfoil using computational fluid dynamics software to determine lift, drag, and moment coefficients and compare to previous published results. Flow separation was visualized beginning around 14 degrees angle of attack. Coefficient values matched closely with the original published data. The airfoil was designed to generate a lift coefficient of 0.68 near 5 degrees angle of attack, avoiding flow separation at the design point through boundary layer control.
This document summarizes research on modeling extreme hurricane winds and insured losses in the United States. The researchers use extreme value theory and Bayesian statistical methods to estimate return levels of hurricane winds for different regions and time periods. They find higher return levels are associated with warmer climate conditions. The same methods are applied to model insured hurricane losses and estimate extreme potential losses under different climate scenarios.
This document describes the development of a new MATLAB/GUI-based thermochemical code called Combustion-Toolbox. The code can perform various thermochemical calculations including chemical equilibrium, shock waves, and detonations. It uses NASA's thermodynamic database and has been validated against other codes. The Combustion-Toolbox provides a graphical user interface and can perform parametric sweeps to analyze combustion problems and estimate properties like adiabatic flame temperature and detonation velocity as a function of equivalence ratio.
Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas...IOSR Journals
This document presents a new natural gas compressibility factor correlation developed specifically for Niger Delta gas fields in Nigeria. Laboratory PVT reports from 22 gas reservoirs in the Niger Delta were compiled into a database and used to evaluate existing compressibility factor correlations. A new correlation was then developed using the database. The performance of the new correlation was found to have the lowest standard error and absolute error compared to other evaluated correlations when calculating z-factors for different Niger Delta reservoir systems. Statistical analysis also showed the new correlation had the highest correlation coefficients and best matched experimental and other estimated z-factor values. It was concluded that the new developed correlation and that of Papay correlation are the most appropriate for calculating natural gas compressibility factors in Niger Delta gas fields
Computational and Experimental Study of the Aerodynamics of a Micro Air VehicleErin Williams
The final presentation of my Final Year Project (Dissertation) to complete the final year of my Aerospace Engineering MEng. For more information about this project see the 'Projects' section of my LinkedIn profile.
Dr. Kei Lau is an expert in aerothermodynamics and hypersonic vehicle design. He has extensive experience with theoretical and experimental analysis techniques as well as computational fluid dynamics and thermal analysis. His work has focused on issues like boundary layer transition and thermal protection system design for programs such as the National Aero-Space Plane. High-fidelity simulation tools are needed to reduce uncertainty in hypersonic vehicle design, including computational fluid dynamics, conjugate heat transfer analysis, and finite element structural analysis.
A strategy for an efficient simulation of countcorrent flows in the iron blas...Josué Medeiros
This document summarizes a strategy for efficiently simulating countercurrent gas and solids flows in an iron blast furnace. Key aspects of the strategy include:
1) Modeling the gas flow using an anisotropic Ergun equation that accounts for layered porous media and can be solved using a computationally efficient algorithm.
2) Modeling the slow descending solids flow using an irrotational flow assumption and conservation of mass.
3) Modeling heat transfer between the gas and solids using energy balance equations that account for convection and heat exchange, with appropriate enthalpy-temperature relationships.
4) Accounting for the stagnant central "deadman" zone and high-flow "race
This document provides a review of turbulent combustion modeling closures for large eddy simulations (LES), with a focus on models applicable to propulsion applications. It identifies three classes of models that can provide broad-based modeling: flamelet-library/presumed PDF models, linear eddy based (LEM) models, and transported PDF or filtered density function (FDF) based models. The document discusses the fundamental physical assumptions of these models, particularly regarding the presumed size of the turbulent scalar manifold. It also provides novel results from direct numerical simulations testing some assumptions using flames with detailed and reduced chemistry models.
The document describes the monitoring instrumentation used for a helium liquefier system at the University of North Florida Physics Department. It discusses a hygrometer and purity meter that detect impurities like water moisture in stored helium gas and indicate when maintenance is needed. It also describes setting up and collaborating on a LabVIEW program to ensure proper operation of these instruments for efficient liquefaction of helium gas.
This document presents explicit analytical solutions for pressure across oblique shock and expansion waves in supersonic flow. It begins by introducing the need for explicit pressure-deflection solutions in solving aerodynamic problems. It then presents:
1) Exact explicit solutions for pressure coefficient and ratio across weak and strong oblique shock waves as functions of deflection angle.
2) Third-order accurate explicit unitary solutions for pressure coefficient and ratio across oblique shocks and expansions as functions of deflection angle.
3) Numerical validation showing good agreement of the new explicit solutions with exact solutions for a range of Mach numbers and deflection angles.
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
The document summarizes an exergy and exergo-economic analysis of the Montazer Ghaem gas turbine power plant in Iran. The analysis finds that the combustion chamber has the highest exergy destruction due to the large temperature difference between the flame and operating fluid. The gas turbine's performance and efficiency are significantly affected by ambient temperature. An increase in ambient temperature decreases the net power output and exergy efficiency. The exergo-economic analysis determines that the combustion chamber also has the largest cost of exergy destruction.
1. The document numerically investigates turbulent air flow in a coaxial jet burner using Reynolds Averaged Navier Stokes (RANS) modeling.
2. It compares predicted results of air axial velocity, air swirl velocity, and turbulent kinetic energy at different axial positions to experimental measurements from a previous study.
3. The simulation results show good agreement with experimental data, except at side regions where air velocity is under estimated, demonstrating RANS is a reasonably accurate approach for modeling industrial turbulent flows.
A Novel Technique in Software Engineering for Building Scalable Large Paralle...Eswar Publications
Parallel processing is the only alternative for meeting computational demand of scientific and technological advancement. Yet first few parallelized versions of a large application code- in the present case-a meteorological Global Circulation Model- are not usually optimal or efficient. Large size and complexity of the code cause making changes for efficient parallelization and further validation difficult. The paper presents some novel techniques to enable change of parallelization strategy keeping the correctness of the code under control throughout the modification.
On assessing the accuracy of offshore wind turbine reliability based designabelkrusnik02
This document discusses assessing the accuracy of design loads derived using the environmental contour method for offshore wind turbines. It compares design loads from this method to exact solutions using full integration over the failure domain. The environmental contour method makes two key assumptions that are often violated: 1) the limit state surface is well approximated by a tangent hyperplane at the design point, and 2) only a single failure mode is considered. This can introduce errors since wind turbine failure can occur under different operating conditions. The document examines these sources of error using an offshore wind turbine located at two Danish sites, Rødsand and Horns Rev, and their differing environmental conditions.
Consequence assessment methods for incidents from lngaob
This document summarizes methods for assessing consequences of incidents involving releases from liquefied natural gas carriers. It recommends using an orifice model to estimate release rates, Webber's methodology to model pool spreading accounting for frictional forces, and heat transfer theory to calculate heat flux to boiling pools. For fires, it recommends using a solid flame model. It also provides injury and damage criteria for assessing impacts to people and structures from thermal radiation. The document notes limitations in current models and calls for additional research, particularly spill tests, to improve accuracy.
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Ten most popular software for prediction of cyclonic stormsMrinmoy Majumder
In recent years the frequency and intensity of cyclones and hurricanes have been increased manifold compared to the last decade. As a result, the necessity for the development of computer models to predict the track, intensity, and time of occurrence of cyclonic storms has increased to avoid loss of life and prevention of damages to public properties. In this presentaion I had tried to highlight the ten most used models in this aspect which are responsible for saving millions of life and their livelihood.
Combustion and Mixing Analysis of a Scramjet Combustor Using CFDijsrd.com
This document summarizes a computational fluid dynamics (CFD) study of combustion and mixing in a scramjet combustor. The study uses ANSYS Fluent software to model flow inside a scramjet combustor geometry for hydrogen, diesel, and methane fuels. The objectives are to determine the flow field and maximize thrust at a Mach number of 2. Key findings include that combustion increases recirculation behind the flameholder strut compared to mixing alone, and shockwaves from the strut facilitate combustion ignition in regions with fuel-air mixing. Meshing of the combustor geometry and strut are discussed.
Comparison of Two Dispersion Models_A Bulk Petroleum Storage Terminal Case St...BREEZE Software
"This study presents a comparison of the pollutant concentration predictions from the
AERMOD and ISC air dispersion models in the context of
fugitive storage tank emissions at a bulk petroleum storage terminal."
Aerodynamic Analysis of the Liebeck L2573 High-Lift AirfoilTodd Ramsey
The document analyzes the L2573 high-lift airfoil using computational fluid dynamics software to determine lift, drag, and moment coefficients and compare to previous published results. Flow separation was visualized beginning around 14 degrees angle of attack. Coefficient values matched closely with the original published data. The airfoil was designed to generate a lift coefficient of 0.68 near 5 degrees angle of attack, avoiding flow separation at the design point through boundary layer control.
This document summarizes research on modeling extreme hurricane winds and insured losses in the United States. The researchers use extreme value theory and Bayesian statistical methods to estimate return levels of hurricane winds for different regions and time periods. They find higher return levels are associated with warmer climate conditions. The same methods are applied to model insured hurricane losses and estimate extreme potential losses under different climate scenarios.
This document describes the development of a new MATLAB/GUI-based thermochemical code called Combustion-Toolbox. The code can perform various thermochemical calculations including chemical equilibrium, shock waves, and detonations. It uses NASA's thermodynamic database and has been validated against other codes. The Combustion-Toolbox provides a graphical user interface and can perform parametric sweeps to analyze combustion problems and estimate properties like adiabatic flame temperature and detonation velocity as a function of equivalence ratio.
Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas...IOSR Journals
This document presents a new natural gas compressibility factor correlation developed specifically for Niger Delta gas fields in Nigeria. Laboratory PVT reports from 22 gas reservoirs in the Niger Delta were compiled into a database and used to evaluate existing compressibility factor correlations. A new correlation was then developed using the database. The performance of the new correlation was found to have the lowest standard error and absolute error compared to other evaluated correlations when calculating z-factors for different Niger Delta reservoir systems. Statistical analysis also showed the new correlation had the highest correlation coefficients and best matched experimental and other estimated z-factor values. It was concluded that the new developed correlation and that of Papay correlation are the most appropriate for calculating natural gas compressibility factors in Niger Delta gas fields
Computational and Experimental Study of the Aerodynamics of a Micro Air VehicleErin Williams
The final presentation of my Final Year Project (Dissertation) to complete the final year of my Aerospace Engineering MEng. For more information about this project see the 'Projects' section of my LinkedIn profile.
Dr. Kei Lau is an expert in aerothermodynamics and hypersonic vehicle design. He has extensive experience with theoretical and experimental analysis techniques as well as computational fluid dynamics and thermal analysis. His work has focused on issues like boundary layer transition and thermal protection system design for programs such as the National Aero-Space Plane. High-fidelity simulation tools are needed to reduce uncertainty in hypersonic vehicle design, including computational fluid dynamics, conjugate heat transfer analysis, and finite element structural analysis.
A strategy for an efficient simulation of countcorrent flows in the iron blas...Josué Medeiros
This document summarizes a strategy for efficiently simulating countercurrent gas and solids flows in an iron blast furnace. Key aspects of the strategy include:
1) Modeling the gas flow using an anisotropic Ergun equation that accounts for layered porous media and can be solved using a computationally efficient algorithm.
2) Modeling the slow descending solids flow using an irrotational flow assumption and conservation of mass.
3) Modeling heat transfer between the gas and solids using energy balance equations that account for convection and heat exchange, with appropriate enthalpy-temperature relationships.
4) Accounting for the stagnant central "deadman" zone and high-flow "race
This document provides a review of turbulent combustion modeling closures for large eddy simulations (LES), with a focus on models applicable to propulsion applications. It identifies three classes of models that can provide broad-based modeling: flamelet-library/presumed PDF models, linear eddy based (LEM) models, and transported PDF or filtered density function (FDF) based models. The document discusses the fundamental physical assumptions of these models, particularly regarding the presumed size of the turbulent scalar manifold. It also provides novel results from direct numerical simulations testing some assumptions using flames with detailed and reduced chemistry models.
The document describes the monitoring instrumentation used for a helium liquefier system at the University of North Florida Physics Department. It discusses a hygrometer and purity meter that detect impurities like water moisture in stored helium gas and indicate when maintenance is needed. It also describes setting up and collaborating on a LabVIEW program to ensure proper operation of these instruments for efficient liquefaction of helium gas.
This document presents explicit analytical solutions for pressure across oblique shock and expansion waves in supersonic flow. It begins by introducing the need for explicit pressure-deflection solutions in solving aerodynamic problems. It then presents:
1) Exact explicit solutions for pressure coefficient and ratio across weak and strong oblique shock waves as functions of deflection angle.
2) Third-order accurate explicit unitary solutions for pressure coefficient and ratio across oblique shocks and expansions as functions of deflection angle.
3) Numerical validation showing good agreement of the new explicit solutions with exact solutions for a range of Mach numbers and deflection angles.
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
The document summarizes an exergy and exergo-economic analysis of the Montazer Ghaem gas turbine power plant in Iran. The analysis finds that the combustion chamber has the highest exergy destruction due to the large temperature difference between the flame and operating fluid. The gas turbine's performance and efficiency are significantly affected by ambient temperature. An increase in ambient temperature decreases the net power output and exergy efficiency. The exergo-economic analysis determines that the combustion chamber also has the largest cost of exergy destruction.
1. The document numerically investigates turbulent air flow in a coaxial jet burner using Reynolds Averaged Navier Stokes (RANS) modeling.
2. It compares predicted results of air axial velocity, air swirl velocity, and turbulent kinetic energy at different axial positions to experimental measurements from a previous study.
3. The simulation results show good agreement with experimental data, except at side regions where air velocity is under estimated, demonstrating RANS is a reasonably accurate approach for modeling industrial turbulent flows.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes previous numerical studies of detonation waves in premixed hydrogen-air mixtures and assesses the accuracy of simplified chemical reaction mechanisms. It describes the classical ZND detonation wave structure and compares numerical results to ZND theory. Several chemical mechanisms of varying complexity are evaluated using zero-dimensional combustion simulations and one-dimensional detonation wave simulations. Comparisons to experimental detonation speeds help validate the chemical models. The document discusses limitations of previous studies and aims to better understand the effects of chemical kinetics models on computed detonation wave structures.
The document summarizes the development of a new small-bore light gas gun (LGG) launcher. Experimental analysis showed that the current dual-pressure breech design did not allow the sabot to reach its full potential velocity. 3D simulations of the breech's internal ballistics informed a redesign to a three-pressure system. The simulations indicated that increasing the gas flow rate through larger valve diameters and using a three-pressure breech with separate chambers for the driving pressure and launching piston would optimize performance and allow for more controlled collision velocities. Future work will include implementing and testing the new three-pressure breech design.
Numerical Simulation of Flow in a Solid Rocket Motor: Combustion Coupled Pres...inventionjournals
Acomputational study is performed for the simulation of reactive fluid flow in a solid rocket motor chamber with pressure dependent propellant burning surface regression. The model geometry consists of a 2D end burning lab-scale motor. Complete conservation equations of mass, momentum, energy and species are solved with finite rate chemistry. The pressure dependent regressive boundary in the combustion chamber is treated by use of remeshing techniques. Hydrogen and propane combustion processes are examined. Time dependent pressure and burning rate variations are illustrated comprehensively. Temperature and species mass fraction variations are given within the flame zone. Temperature, velocity and density distributions are compared for both constant burning rate and pressure dependent burning rate simulations.
Characteristics of shock reflection in the dual solution domainSaif al-din ali
This document summarizes a numerical study that investigates the use of laser energy deposition to induce transitions between regular and Mach shock reflections in supersonic flow over dual wedge configurations. The study validated its numerical approach by comparing results to an experiment involving laser deposition in front of a sphere. Simulations then examined how varying the position and amount of laser energy deposition could influence transition characteristics in the dual solution domain over wedge configurations. Key findings included how transition time and occurrence depended on deposition parameters and position relative to the shock waves and wedges.
Characteristics of shock reflection in the dual solution domainSaif al-din ali
This document summarizes a numerical study that investigated the effects of laser energy deposition on shock reflection transitions in supersonic flow. The study used computational fluid dynamics simulations to model laser energy being deposited in front of symmetrical wedges, creating a dual solution domain where different shock reflection patterns can occur. The results showed that laser energy deposition could induce transitions between regular and Mach shock reflections, and that the transition characteristics depended on the location and amount of energy deposited. Depositing more energy required more time for transition, and transition did not occur above a certain energy level or when depositing on the centerline.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes an experimental investigation into the regression rate behavior of hydroxyl-terminated polybutadiene (HTPB) solid fuel burning with oxygen in a hybrid rocket motor. Key findings include:
1) Real-time x-ray radiography was used to obtain instantaneous solid fuel regression rate data at many axial locations in the motor. Regression rates had a strong dependence on axial location near the head-end of the motor.
2) Thermocouple measurements indicated fuel surface temperatures between 930 and 1190 K. The estimated activation energy of 11.5 kcal/mole suggests the overall regression process is governed by physical desorption of high-molecular weight fragments from the fuel surface.
Cfd analysis of turbulence in a gas turbine combustor with reference to the c...IAEME Publication
This document discusses computational fluid dynamics (CFD) analysis of turbulence in a gas turbine combustor with reference to exit phenomena. It summarizes several studies that have used experimental and computational methods to model combustor exit profiles and their effects on secondary flows in turbine vanes. The document outlines CFD models of different combustor configurations, including variations in cooling schemes, dilution jets, and exit slots. Results show that dilution jets and exit slots can create non-uniformities in temperature, pressure and velocity at the combustor exit which influence the development of secondary flows in downstream vanes. Understanding these interactions is important for improving turbine performance and cooling effectiveness.
Cfd analysis of turbulence in a gas turbine combustor with reference to the c...IAEME Publication
This document discusses computational fluid dynamics (CFD) analysis of turbulence in a gas turbine combustor with reference to exit phenomena. It analyzes the interaction between the combustor and turbine regarding increased temperatures and heat transfer. The objective is to better understand non-uniformities in the flow field at the combustor exit in terms of temperature, pressure and velocity in the spanwise and pitchwise directions. The analysis uses CFD to model different combustor configurations and evaluate the effects on the exit flow field and downstream turbine vane.
An Offshore Natural Gas Transmission Pipeline Model and Analysis for the Pred...IOSRJAC
The purpose of this paper is to model and analyze an existing natural gas transmission pipeline – the 24-inch, 5km gas export pipeline of the Amenam-Kpono field, Niger Delta, Nigeria – to determine properties such as pressure, temperature, density, flow velocity and, in particular, dew point, occurring at different segments of the pipeline, and to compare these with normal pipeline conditions in order to identify the segments most susceptible to condensation/hydrate formation so that cost-effective and efficient preventive/remedial actions can be taken. The analysis shows that high pressure and low temperature favor condensation/hydrate formation, and that because these conditions are more likely in the lower half of the pipeline system, remedial/preventive measures such as heating/insulation and inhibition injection should be channeled into that segment for cost optimization..
Arbitrary Lagrange Eulerian Approach for Bird-Strike Analysis Using LS-DYNAdrboon
In this third and last sequence paper we focus on developing a model to simulate bird-strike events using Lagrange and Arbitrary Lagrange Eulerian (ALE) in LS-DYNA. We developed a standard work for the two-and three-dimensional models for bird-strike events. We modeled the bird as a cylinder fluid and the fan blade as a plate. The case study was that of frontal impact of soft-bodies on rigid plates based on the Lagrangian Bird Model. Results show very good agreement with available test data and within 7% error when compared with the Lagrange and SPH methods. The developed ALE approach is suitable for bird-strike events in tapered plates.
This document summarizes a study on using computational fluid dynamics (CFD) to model and analyze the heat transfer performance of ceramic heat exchangers with different duct cross-sectional shapes (rectangular, elliptical, cylindrical). CFD was used to calculate parameters like temperature distribution, velocity distribution, heat transfer rate, and effectiveness. The predicted heat transfer rate from CFD analysis was found to be 15% higher than theoretical calculations. Analysis showed that cylindrical ducts had the highest effectiveness at 62%, followed by elliptical at 55% and rectangular at 52%. The document also provides background on the need to improve energy efficiency and reduce emissions, and discusses objectives, assumptions, and modeling steps of the CFD analysis.
international research journal of engineering and technology 3 nov.pdfnareshkotra
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining a proper peer review and the use of recommended electronic formats for an article delivery expedites the process of All submitted research articles are subjected to an immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as assure that they are likely to be the level of interest and importance of appropriate for the journal.
This document summarizes a study on using computational fluid dynamics (CFD) to model and analyze the heat transfer performance of ceramic heat exchangers with different duct cross-sectional shapes (rectangular, elliptical, cylindrical). CFD was used to calculate parameters like temperature distribution, velocity distribution, heat transfer rate, and effectiveness. The predicted heat transfer rate from CFD analysis was found to be 15% higher than theoretical calculations. Analysis showed that cylindrical ducts had the highest effectiveness at 62%, followed by elliptical at 55% and rectangular at 52%. The document also provides background on the need to improve energy efficiency and reduce emissions, and discusses objectives, assumptions, and methodology of the CFD modeling and analysis.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining rigorous peer review the use of recommended electronic formats for article delivery expedites the process All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
This document summarizes a numerical investigation into the effects of roughness on near-bed turbulence characteristics in oscillatory flows. Direct numerical simulations were performed for two particle sizes corresponding to large gravel and small sand particles. A double-averaging technique was used to study the wake field spatial inhomogeneities introduced by the roughness. Preliminary results showed additional production and transport terms in the double-averaged Reynolds stress budgets, indicating alternate turbulent energy transfer pathways. Budgets of normal Reynolds stress components revealed redistribution of energy from the streamwise to other components due to pressure work. The large gravel particles significantly modulated near-bed flow structures and isotropization, while elongated horseshoe structures formed for the sand case due to high shear. Redistribution of energy
This document summarizes research on supersonic combustion ramjet (scramjet) technologies conducted between 2004 and 2012. It focuses on three key areas: 1) fuel control and injection of gaseous, supercritical, and multiphase fuels, 2) ignition, flameholding, and flame propagation in supersonic flows, and 3) laser diagnostic measurements. The research aims to advance the scientific understanding needed to design high-speed air-breathing propulsion systems.
This dissertation examines high-fidelity simulations and modeling of compressible reacting flows. Direct numerical simulations are performed of a supersonic reacting mixing layer to explore the physics of supersonic combustion. An efficient compressible flamelet/progress variable combustion model is introduced and validated using the DNS databases. The combustion model is then applied to simulate a hydrogen jet in supersonic cross-flow and the HIFiRE scramjet configuration.
This thesis examines the three-dimensional reacting flow analysis of a cavity-based scramjet combustor through computational fluid dynamics (CFD) modeling. The author develops a CFD code to solve the Navier-Stokes equations coupled with finite rate chemical reactions. An ethylene-air combustion model is used. Grid refinement studies and comparisons of numerical schemes are performed. The effects of fuel injection angle and additional downstream injectors on mixing efficiency are also investigated. The goal is to analyze reacting flows in scramjet combustors and explore methods to improve performance.
This document summarizes large eddy simulations of supersonic non-reactive and reactive flows performed with an immersed boundary method on two configurations. The first test case is a Mach 3.5 flow over a cylinder, which showed excellent agreement with theory. The second case is a supersonic hydrogen-air burner, where comparisons to experimental data for species mass fractions and temperature also led to good agreement. The impact of burner geometry on the velocity and species fields was studied using the immersed boundary method.
This document summarizes large eddy simulations of a supersonic hydrogen-air burner performed with the SiTComB numerical code. Three mesh resolutions were considered: 2, 30, and 113 million points. The 30 million point case improved predictions of flame lift-off height compared to 2 million points, but further refinement to 113 million points was needed to match experimental results. Autoignition delays calculated with a reduced kinetic scheme agreed well with detailed chemistry models.
This report summarizes experimental studies of premixed flame structure and propagation in compressible turbulent flows. Major accomplishments include: 1) Development of subsonic and supersonic experimental facilities to generate premixed flows with controllable turbulence over a range of Mach numbers. 2) Characterization of the turbulent flows using diagnostics such as hot-wire anemometry, PIV and OH-PLIF. 3) Analysis of laser-ignited flame kernel growth in the turbulent premixed flows, showing good agreement with low speed studies but deviation with increasing Mach number. The results provide new insight into premixed combustion in highly turbulent compressible conditions.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
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
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
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.
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.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
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%.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
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
Literature Review Basics and Understanding Reference Management.pptx
Scramjet
1. 9/8/2017 Review of Numerical Modeling and Simulation Results Pertaining to High-speed Combustion in Scramjets
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Review of Numerical Modeling and Simulation Results
Pertaining to High-speed Combustion in Scramjets
Ryan J. Clark* and S. O. Bade Shrestha†
Western Michigan University, Kalamazoo, Michigan, 49008
This paper is a reviewof numerical modeling of high-speedcombustion as it pertains to
scramjets. Simulation results are presentedfrom numerous researchers that have devoted
their time andeffort to numerically investigate high-speedcombustion in scramjets. In
addition to their findings validation work is presented, showing the validity of ANSYS
Fluent 12.1 in the application of high-speedcombustion in scramjets.
I. Introduction
OR approximately sixty years there has been a global effort to expand upon the understanding of supersonic
combustion through fundamental and experimental research. There are numerous fluid dynamic phenomena to
independently research within the area of supersonic combustion, specifically with the development of the scramjet
engine. Though much advancement has been made in the development of the scramjet, further understanding of the
fluid dynamic processes in high-speed combustion in the scramjet is required if it is to reach its long-termgoals
(e.g., implementation in responsive space access; long-range, prompt global strike; and future high speed
transportation). This paper reviews past numerical simulation research pertaining to scramjet combustion and
presents simulation results validating the use of ANSYS Fluent 12.1 in the application of scramjet combustion. It
begins with introducing past reviews conducted by the Air Force, NASA, and others, followed by a summary of
numerical simulations on scramjet combustion conducted in recent years.
II. Review
In 1996 a review was conducted as a joint effort by the Air Force Office of Scientific Research, the Air Force
Wright Laboratory Aero Propulsion and Power Directorate, and the NASA Langley Research Center1. The purpose
of their review was much more extensive than the one being presented within this work. Their review discussed the
scramjet in its entirety. The review by the Air Force and NASA concluded with a list of areas that need further
research. In regards to combustion there was an expressed need for the following: further research with emphasis on
unsteady analysis of combustion instability; improved turbulence modeling techniques of high speed reacting flows
to accurately predict the interactions between turbulence and chemical reactions; further research implementing
turbulence models based on the probability density functions; and advancements in large eddy simulation (LES)
with the development of subgrid scale models appropriate to high-speed compressible flow1.
A more recent review of scramjet combustion, including the mixing process, was presented in the 2010 issue of
the AIAA Journal. This review consisted of a summary of five papers which established the standing of scramjet
combustion and mixing as of 20102. The first summary was of the work conducted by Ingenito and Bruno, who
investigated supersonic reacting flow for the case of hydrogen injection at Mach 2.5 into an airstreamflowing at
Mach 2, using the NASA-Langley combustor model3. Three-dimensional, large eddy simulations were implemented
using a subgrid scale model, ISCM, which was developed specifically for supersonic combustion. More specifically,
F
Downloaded by UNIVERSITY OF OKLAHOMA on August 18, 2013 | http://arc.aiaa.org | DOI: 10.2514/6.2013-3724
49th AIAA/ASME/SAE/ASEE Joint PropulsionConference
July 14 - 17, 2013, San Jose, CA
AIAA 2013-3724