The document discusses vibration control techniques for marine diesel engines. It describes how tuned mass dampers can be used to reduce engine vibration levels by altering the natural frequencies of the engine structure. A tuned mass damper works by adding a mass with flexible elements that produces counteracting forces against the engine's vibrations. The document provides details on how tuned mass dampers were used successfully to reduce vibrations on Wärtsilä 9L46 engines by tuning the damper to match specific excitation frequencies from the engine. Analysis of engine dynamics and testing of tuned mass damper prototypes were required to design effective vibration control solutions.
Suspension Systems & Components design & AnalysisVinay Tiwari
The document discusses suspension systems and components. It outlines the objectives of suspension systems which include providing good ride and handling performance, ensuring steering control is maintained during maneuvering, and providing isolation from high frequency vibrations. It describes types of independent and dependent suspensions and components such as springs, dampers, wishbones. It covers analyses like mobility, kinematics and forces in suspension members for different load conditions. Different suspension configurations are discussed including MacPherson strut, double wishbone, solid axle leaf spring systems.
El documento describe el funcionamiento del motor de cuatro tiempos, el cual realiza sus funciones en cuatro tiempos o ciclos: admisión, compresión, ignición/explosión y escape. Explica las partes principales de este tipo de motor como el cilindro, pistón, biela y cigüeñal, así como las ventajas e inconvenientes frente a un motor de dos tiempos. Además, brinda detalles sobre el inventor Nikolaus Otto y los usos actuales de los motores de cuatro tiempos.
El documento describe los sistemas de inyección electrónica a gasolina. Explica que estos sistemas son más eficientes que los carburadores, reduciendo la contaminación y mejorando la economía de combustible y el rendimiento. También clasifica los sistemas de inyección según cuatro características y describe los componentes clave como la bomba de combustible, filtros, regulador de presión, riel de combustible, inyectores y sensores.
Design, Analysis and Simulation of Double Wishbone Suspension System for Form...IRJET Journal
This document describes the design, analysis, and simulation of a double wishbone suspension system for a formula student racing vehicle. The authors first discuss the basic parameters and requirements for the suspension system. They then describe the detailed design of the knuckle, wishbones, and helical coil spring. Finite element analysis is conducted on these components using ANSYS to analyze stresses and deformations. Finally, dynamic simulation of the full suspension system is performed using ADAMS software to analyze how kinematic parameters like camber angle and roll steer change with wheel travel. The results of the simulation match the designed parameters and help validate the suspension system design.
El documento describe los diferentes componentes y sistemas de frenos en vehículos. Explica los tipos de frenos, la dinámica del frenado incluyendo fuerza de frenado y deceleración, y cómo se genera la fuerza a través de frenos de tambor y de disco. También cubre los sistemas de accionamiento, circuitos hidráulicos y neumáticos, y efectos sobre la estabilidad como la basculación. Incluye prácticas sobre comparar la fuerza de frenado con discos de diferentes diámetros y identificar componentes del fre
This presentation discusses internal combustion engines. It provides an introduction and overview of external combustion engines and internal combustion engines. It then focuses on internal combustion engines, describing their main parts like the cylinder block, cylinder head, piston, connecting rod, crankshaft, valves, spark plug, injector, manifold, and camshaft. It also defines important engine terminology and classifications of internal combustion engines. The advantages of internal combustion engines are listed as having higher efficiency than external combustion engines while also being more compact and having a lower initial cost.
The document discusses the advancement of internal combustion engines. It covers topics like the classification of IC engines based on combustion and strokes. Major areas of advancement discussed include engine design, material selection, timing controls, fuels and fuel injection systems, and pollution control. Some specific technologies covered are variable valve timing, direct injection, superchargers, turbochargers, six-stroke engines, and methods to reduce air pollution from engines like catalytic converters. The goals of engine advancement are listed as higher power, better fuel efficiency, lower emissions and weight.
i. Introduction:
ii. Definition of Turbo machine,
iii. Parts of Turbo machines,
iv. Comparison with positive displacement machines,
v. Classification of Turbo machine,
vi. Dimensionless parameters and their significance,
vii. Unit and specific quantities,
viii. Model studies and its numerical.
(Note: Since dimensional analysis is covered in Fluid Mechanics subject, questions on dimensional analysis may not be given. However, dimensional parameters and model studies may be given more weightage.)
Simple Numerical; on Model Analysis.
previous year question papers solved
Suspension Systems & Components design & AnalysisVinay Tiwari
The document discusses suspension systems and components. It outlines the objectives of suspension systems which include providing good ride and handling performance, ensuring steering control is maintained during maneuvering, and providing isolation from high frequency vibrations. It describes types of independent and dependent suspensions and components such as springs, dampers, wishbones. It covers analyses like mobility, kinematics and forces in suspension members for different load conditions. Different suspension configurations are discussed including MacPherson strut, double wishbone, solid axle leaf spring systems.
El documento describe el funcionamiento del motor de cuatro tiempos, el cual realiza sus funciones en cuatro tiempos o ciclos: admisión, compresión, ignición/explosión y escape. Explica las partes principales de este tipo de motor como el cilindro, pistón, biela y cigüeñal, así como las ventajas e inconvenientes frente a un motor de dos tiempos. Además, brinda detalles sobre el inventor Nikolaus Otto y los usos actuales de los motores de cuatro tiempos.
El documento describe los sistemas de inyección electrónica a gasolina. Explica que estos sistemas son más eficientes que los carburadores, reduciendo la contaminación y mejorando la economía de combustible y el rendimiento. También clasifica los sistemas de inyección según cuatro características y describe los componentes clave como la bomba de combustible, filtros, regulador de presión, riel de combustible, inyectores y sensores.
Design, Analysis and Simulation of Double Wishbone Suspension System for Form...IRJET Journal
This document describes the design, analysis, and simulation of a double wishbone suspension system for a formula student racing vehicle. The authors first discuss the basic parameters and requirements for the suspension system. They then describe the detailed design of the knuckle, wishbones, and helical coil spring. Finite element analysis is conducted on these components using ANSYS to analyze stresses and deformations. Finally, dynamic simulation of the full suspension system is performed using ADAMS software to analyze how kinematic parameters like camber angle and roll steer change with wheel travel. The results of the simulation match the designed parameters and help validate the suspension system design.
El documento describe los diferentes componentes y sistemas de frenos en vehículos. Explica los tipos de frenos, la dinámica del frenado incluyendo fuerza de frenado y deceleración, y cómo se genera la fuerza a través de frenos de tambor y de disco. También cubre los sistemas de accionamiento, circuitos hidráulicos y neumáticos, y efectos sobre la estabilidad como la basculación. Incluye prácticas sobre comparar la fuerza de frenado con discos de diferentes diámetros y identificar componentes del fre
This presentation discusses internal combustion engines. It provides an introduction and overview of external combustion engines and internal combustion engines. It then focuses on internal combustion engines, describing their main parts like the cylinder block, cylinder head, piston, connecting rod, crankshaft, valves, spark plug, injector, manifold, and camshaft. It also defines important engine terminology and classifications of internal combustion engines. The advantages of internal combustion engines are listed as having higher efficiency than external combustion engines while also being more compact and having a lower initial cost.
The document discusses the advancement of internal combustion engines. It covers topics like the classification of IC engines based on combustion and strokes. Major areas of advancement discussed include engine design, material selection, timing controls, fuels and fuel injection systems, and pollution control. Some specific technologies covered are variable valve timing, direct injection, superchargers, turbochargers, six-stroke engines, and methods to reduce air pollution from engines like catalytic converters. The goals of engine advancement are listed as higher power, better fuel efficiency, lower emissions and weight.
i. Introduction:
ii. Definition of Turbo machine,
iii. Parts of Turbo machines,
iv. Comparison with positive displacement machines,
v. Classification of Turbo machine,
vi. Dimensionless parameters and their significance,
vii. Unit and specific quantities,
viii. Model studies and its numerical.
(Note: Since dimensional analysis is covered in Fluid Mechanics subject, questions on dimensional analysis may not be given. However, dimensional parameters and model studies may be given more weightage.)
Simple Numerical; on Model Analysis.
previous year question papers solved
El documento describe los sistemas de inyección Diesel, incluyendo una breve historia de su desarrollo. Explica que las primeras bombas de inyección Diesel se fabricaron en 1927 y desde entonces se han ido perfeccionando, llegando a versiones más silenciosas, económicas, limpias y seguras. También describe los principales componentes de los sistemas de inyección, como bombas en línea, bombas distribuidoras y nuevas tecnologías como Common Rail.
The document discusses turbochargers and superchargers. It begins by explaining how engine power depends on air intake and efficiency. It then describes three methods to increase air consumption: increasing displacement, running at higher speeds, and increasing charge density. Superchargers and turbochargers both increase charge density by compressing air intake. A supercharger is mechanically driven while a turbocharger uses exhaust gas energy. The document outlines the components, working principles, advantages, disadvantages, and selection process for turbochargers. It also presents experimental results showing increased torque, power, and reduced exhaust temperatures from a turbocharged tractor engine compared to naturally aspirated.
Engine friction is mainly due to sliding and rotating parts. It can be categorized into direct frictional losses, pumping losses, power losses to drive components like the scavenging pump, and power losses to drive auxiliary components. Several factors affect mechanical friction, like engine design, speed, load, temperature, oil viscosity, and lubrication system design. Proper lubrication is essential to reduce friction and wear between engine components. The key types of lubrication systems are mist, wet sump, and dry sump systems. Engine oil must have appropriate properties like viscosity, viscosity index, corrosion resistance, and stability.
Single Speed Transmission for Electric VehiclesSameer Shah
This document summarizes Sameer Shah's seminar report on designing a single speed transmission for electric vehicles. The report describes the design process for a helical gear transmission with a gear ratio of 12.25:1 to meet the torque requirements of an electric vehicle. Structural simulation was performed on the gears to validate they could withstand the expected loads. The gears would be manufactured using hobbing or shaping and finished through grinding or honing. Lubrication would be provided by Omega 690 gear oil for its low temperature fluidity and high temperature strength.
El documento describe los tipos y funcionamiento de los inyectores common rail utilizados en motores diésel. Existen dos tipos principales de inyectores: electromagnéticos y piezoeléctricos. Los inyectores electromagnéticos usan una bobina de accionamiento para abrir y cerrar, mientras que los piezoeléctricos usan placas cerámicas que se dilatan y contraen mediante impulsos eléctricos para controlar de forma precisa la inyección de combustible. Ambos tipos funcionan bajo altas presiones
The document is a seminar report submitted for a master's degree in mechanical engineering. It discusses air pollution from internal combustion engines and methods to control emissions. It covers topics like types of pollutants from gasoline and diesel engines, their harmful effects, measurement techniques, and solutions like improving engine design, using cleaner fuels, and installing post-combustion control devices.
This document is a project report on automatic transmission systems submitted by Saswat DaS to his professors at C.V Raman Global University. It provides an overview of automatic transmissions, including their components like planetary gear sets, hydraulic systems, and computer controls. It describes different types of automatic transmissions like continuously variable transmission, dual clutch transmission, and torque converter transmission. It also discusses advantages like smooth shifting and disadvantages like higher costs compared to manual transmissions. The conclusion is that while manual transmissions have been around longer, automatic transmissions are eliminating the need for a clutch pedal and are the future of transmissions.
This document discusses different fuel injection systems for diesel engines, including air injection systems, solid injection systems, and electronic injection systems. It describes the common rail direct injection (CRDI) system, individual pump system, and distributor system as types of solid fuel injection. The document also covers fuel injection pumps, including the jerk type and distributor type pumps. Finally, it discusses different types of nozzles used in injectors, such as pintle, single hole, multiple hole, and pintaux nozzles.
This presentation provide complete study of governor for GTU as well as PU and other university students. It covers basic terminologies, characteristics of governor, diagram, derivations etc. for proper understanding.
Dokumen tersebut membahas latar belakang pemilihan judul skripsi tentang perawatan dan perbaikan sistem rem cakram. Dibahas pula rumusan masalah, tujuan, dan batasan masalah yang akan dibahas dalam skripsi tersebut.
A two-stroke engine has a compression and combustion stroke in each revolution, while a four-stroke engine has separate intake, compression, combustion, and exhaust strokes. In a two-stroke, oil is mixed with gasoline to lubricate parts. Two-stroke engines are lighter and more powerful but less efficient and produce more pollution than four-stroke engines due to exhausting unburned fuel. The piston acts as both a valve and plunger in two-stroke engines.
PERFORMANCE ENHANCEMENT OF SINGLE SLOPE SOLAR STILL USING NANOPARTICLES MIXED...antjjournal
The present paper reports on an experiment to improve the productivity of solar still using nano-particles.Solar distillation is a relatively simple treatment of brackish or impure water. In this solar energy is used to evaporate water then this vapour is condensed as pure water. This process removes salts and other impurities. Latest trend to improve the efficiency of the solar still is use of nano-particles like metal oxides. These particles increase surface area of absorption to solar radiation. In this work the Al2O3 nanoparticles
mixed black paint is used to enhance the productivity of solar still. The solar radiations are transmitted through the glass cover and captured by a black painted inner bottom surface of the solar still. Water absorbs the heat and is converted into vapour within the chamber of the solar still.Single slop solar
still is used from past decades but in this study effect of nano-particles on productivity of solar still is
analyzed. Experimental work is performed for the single slope solar still (SS-SS) under climatic conditions
of Jaipur. The use of the nano-particles mixed with black paint increases the temperature of the solar still
basin. The productivity and efficiency of solar still at water depth 0.01 m with nano-particles are 3.48 litre
and 38.65% respectively which are maximum values compared to water depths 0.02 m and 0.03 m. Results
of the study gives 38.09% increment in productivity and 12.18% increment in thermal efficiency when
nano-particles of size 50 nm to 100 nm mixed black paint used at water depth .01 m. To check the
significance of difference in productivity of solar still with and without nano-particle mixed black paint, a
paired t-Test is performed which is conforms that the productivity enhancement due to nano-particle mixed
black paint is significant at 95% confidence interval.
El sistema de frenos convierte la energía cinética de un vehículo en movimiento en calor para detener las ruedas. Funciona mediante la ley de Pascal y la fricción. La ley de Pascal transmite la presión del fluido de frenos a través del sistema hidráulico, mientras que la fricción entre los componentes del freno y las ruedas detiene el movimiento al convertir la energía cinética en calor. El cilindro maestro es el corazón del sistema y transmite la fuerza del pedal del freno al fluido
A spoiler is an automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across a body of a vehicle in motion, usually described as turbulence or drag
Rotordynamics is the branch of engineering that studies the vibrations of rotating shafts. There are three main modes of vibration during rotation - torsional, longitudinal, and lateral vibrations, with lateral vibrations being the greatest concern. Factors like unbalance, misalignment, and bearing failures can cause rotor failure. Critical speeds occur when the rotational speed matches the natural frequency of the system, potentially leading to resonance. Stability and unbalance response are also major areas of concern in rotordynamics analysis.
This document summarizes fuel systems for spark ignition (SI) engines. It discusses the requirements of a good fuel system, including proper air-fuel ratios for different engine operating conditions. It then describes the basic components and functioning of carburetor systems, including single jet and complete carburetors. It notes the limitations of simple carburetors and discusses additional systems in complete carburetors to overcome these limitations, such as compensating jets, emulsion tubes, back suction controls, auxiliary valves/ports, idling systems, power enrichment systems, and chokes. It briefly introduces throttle body fuel injection and multi-point fuel injection as alternatives to carburetion before petrol/electronic injection systems.
Unit 9 implementing the reliability strategyCharlton Inao
This document discusses implementing reliability strategies and engineering. It begins by explaining the importance of reliability in fields like aviation, defense, and energy where failure could lead to dangerous situations. It then discusses mechanical reliability and common failure modes. Reliability engineering is introduced as the study of reliability and life-cycle management. Several high-profile system failures are listed to emphasize the need for reliability in design. The document outlines various areas of reliability engineering and provides definitions of key terms. It gives examples of reliability calculations and discusses maintainability, availability, and quality. Analytical reliability techniques are also summarized, along with key points and steps to implement a reliability strategy.
Application of CAE Methods to Increase Efficiency in Powertrain DevelopmentSimulationX
The document describes efforts by Jaguar Land Rover, ZF, and ITI GmbH to develop a complete powertrain torsional system model using SimulationX to increase efficiency in powertrain development. A multi-body dynamics model of the engine is coupled to a torque converter damper and 8-speed automatic transmission model. Analysis of the model shows good correlation to test data and allows investigation of noise and vibration issues and optimization of modal placement early in the design process.
This document provides a theory and experimental procedure for demonstrating an undamped vibration absorber. The theory section explains how attaching an auxiliary mass-spring system to a vibrating object can reduce vibrations by extracting the energy that causes them. If the absorber's natural frequency matches the object's frequency, the object's amplitude can be reduced to zero. The experiment uses a beam with a motor to induce vibrations, and an absorber attached below to reduce the beam's amplitude at different motor speeds by adjusting the absorber's mass positions. The goal is to determine the absorber configuration that minimizes the beam's vibrations.
El documento describe los sistemas de inyección Diesel, incluyendo una breve historia de su desarrollo. Explica que las primeras bombas de inyección Diesel se fabricaron en 1927 y desde entonces se han ido perfeccionando, llegando a versiones más silenciosas, económicas, limpias y seguras. También describe los principales componentes de los sistemas de inyección, como bombas en línea, bombas distribuidoras y nuevas tecnologías como Common Rail.
The document discusses turbochargers and superchargers. It begins by explaining how engine power depends on air intake and efficiency. It then describes three methods to increase air consumption: increasing displacement, running at higher speeds, and increasing charge density. Superchargers and turbochargers both increase charge density by compressing air intake. A supercharger is mechanically driven while a turbocharger uses exhaust gas energy. The document outlines the components, working principles, advantages, disadvantages, and selection process for turbochargers. It also presents experimental results showing increased torque, power, and reduced exhaust temperatures from a turbocharged tractor engine compared to naturally aspirated.
Engine friction is mainly due to sliding and rotating parts. It can be categorized into direct frictional losses, pumping losses, power losses to drive components like the scavenging pump, and power losses to drive auxiliary components. Several factors affect mechanical friction, like engine design, speed, load, temperature, oil viscosity, and lubrication system design. Proper lubrication is essential to reduce friction and wear between engine components. The key types of lubrication systems are mist, wet sump, and dry sump systems. Engine oil must have appropriate properties like viscosity, viscosity index, corrosion resistance, and stability.
Single Speed Transmission for Electric VehiclesSameer Shah
This document summarizes Sameer Shah's seminar report on designing a single speed transmission for electric vehicles. The report describes the design process for a helical gear transmission with a gear ratio of 12.25:1 to meet the torque requirements of an electric vehicle. Structural simulation was performed on the gears to validate they could withstand the expected loads. The gears would be manufactured using hobbing or shaping and finished through grinding or honing. Lubrication would be provided by Omega 690 gear oil for its low temperature fluidity and high temperature strength.
El documento describe los tipos y funcionamiento de los inyectores common rail utilizados en motores diésel. Existen dos tipos principales de inyectores: electromagnéticos y piezoeléctricos. Los inyectores electromagnéticos usan una bobina de accionamiento para abrir y cerrar, mientras que los piezoeléctricos usan placas cerámicas que se dilatan y contraen mediante impulsos eléctricos para controlar de forma precisa la inyección de combustible. Ambos tipos funcionan bajo altas presiones
The document is a seminar report submitted for a master's degree in mechanical engineering. It discusses air pollution from internal combustion engines and methods to control emissions. It covers topics like types of pollutants from gasoline and diesel engines, their harmful effects, measurement techniques, and solutions like improving engine design, using cleaner fuels, and installing post-combustion control devices.
This document is a project report on automatic transmission systems submitted by Saswat DaS to his professors at C.V Raman Global University. It provides an overview of automatic transmissions, including their components like planetary gear sets, hydraulic systems, and computer controls. It describes different types of automatic transmissions like continuously variable transmission, dual clutch transmission, and torque converter transmission. It also discusses advantages like smooth shifting and disadvantages like higher costs compared to manual transmissions. The conclusion is that while manual transmissions have been around longer, automatic transmissions are eliminating the need for a clutch pedal and are the future of transmissions.
This document discusses different fuel injection systems for diesel engines, including air injection systems, solid injection systems, and electronic injection systems. It describes the common rail direct injection (CRDI) system, individual pump system, and distributor system as types of solid fuel injection. The document also covers fuel injection pumps, including the jerk type and distributor type pumps. Finally, it discusses different types of nozzles used in injectors, such as pintle, single hole, multiple hole, and pintaux nozzles.
This presentation provide complete study of governor for GTU as well as PU and other university students. It covers basic terminologies, characteristics of governor, diagram, derivations etc. for proper understanding.
Dokumen tersebut membahas latar belakang pemilihan judul skripsi tentang perawatan dan perbaikan sistem rem cakram. Dibahas pula rumusan masalah, tujuan, dan batasan masalah yang akan dibahas dalam skripsi tersebut.
A two-stroke engine has a compression and combustion stroke in each revolution, while a four-stroke engine has separate intake, compression, combustion, and exhaust strokes. In a two-stroke, oil is mixed with gasoline to lubricate parts. Two-stroke engines are lighter and more powerful but less efficient and produce more pollution than four-stroke engines due to exhausting unburned fuel. The piston acts as both a valve and plunger in two-stroke engines.
PERFORMANCE ENHANCEMENT OF SINGLE SLOPE SOLAR STILL USING NANOPARTICLES MIXED...antjjournal
The present paper reports on an experiment to improve the productivity of solar still using nano-particles.Solar distillation is a relatively simple treatment of brackish or impure water. In this solar energy is used to evaporate water then this vapour is condensed as pure water. This process removes salts and other impurities. Latest trend to improve the efficiency of the solar still is use of nano-particles like metal oxides. These particles increase surface area of absorption to solar radiation. In this work the Al2O3 nanoparticles
mixed black paint is used to enhance the productivity of solar still. The solar radiations are transmitted through the glass cover and captured by a black painted inner bottom surface of the solar still. Water absorbs the heat and is converted into vapour within the chamber of the solar still.Single slop solar
still is used from past decades but in this study effect of nano-particles on productivity of solar still is
analyzed. Experimental work is performed for the single slope solar still (SS-SS) under climatic conditions
of Jaipur. The use of the nano-particles mixed with black paint increases the temperature of the solar still
basin. The productivity and efficiency of solar still at water depth 0.01 m with nano-particles are 3.48 litre
and 38.65% respectively which are maximum values compared to water depths 0.02 m and 0.03 m. Results
of the study gives 38.09% increment in productivity and 12.18% increment in thermal efficiency when
nano-particles of size 50 nm to 100 nm mixed black paint used at water depth .01 m. To check the
significance of difference in productivity of solar still with and without nano-particle mixed black paint, a
paired t-Test is performed which is conforms that the productivity enhancement due to nano-particle mixed
black paint is significant at 95% confidence interval.
El sistema de frenos convierte la energía cinética de un vehículo en movimiento en calor para detener las ruedas. Funciona mediante la ley de Pascal y la fricción. La ley de Pascal transmite la presión del fluido de frenos a través del sistema hidráulico, mientras que la fricción entre los componentes del freno y las ruedas detiene el movimiento al convertir la energía cinética en calor. El cilindro maestro es el corazón del sistema y transmite la fuerza del pedal del freno al fluido
A spoiler is an automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across a body of a vehicle in motion, usually described as turbulence or drag
Rotordynamics is the branch of engineering that studies the vibrations of rotating shafts. There are three main modes of vibration during rotation - torsional, longitudinal, and lateral vibrations, with lateral vibrations being the greatest concern. Factors like unbalance, misalignment, and bearing failures can cause rotor failure. Critical speeds occur when the rotational speed matches the natural frequency of the system, potentially leading to resonance. Stability and unbalance response are also major areas of concern in rotordynamics analysis.
This document summarizes fuel systems for spark ignition (SI) engines. It discusses the requirements of a good fuel system, including proper air-fuel ratios for different engine operating conditions. It then describes the basic components and functioning of carburetor systems, including single jet and complete carburetors. It notes the limitations of simple carburetors and discusses additional systems in complete carburetors to overcome these limitations, such as compensating jets, emulsion tubes, back suction controls, auxiliary valves/ports, idling systems, power enrichment systems, and chokes. It briefly introduces throttle body fuel injection and multi-point fuel injection as alternatives to carburetion before petrol/electronic injection systems.
Unit 9 implementing the reliability strategyCharlton Inao
This document discusses implementing reliability strategies and engineering. It begins by explaining the importance of reliability in fields like aviation, defense, and energy where failure could lead to dangerous situations. It then discusses mechanical reliability and common failure modes. Reliability engineering is introduced as the study of reliability and life-cycle management. Several high-profile system failures are listed to emphasize the need for reliability in design. The document outlines various areas of reliability engineering and provides definitions of key terms. It gives examples of reliability calculations and discusses maintainability, availability, and quality. Analytical reliability techniques are also summarized, along with key points and steps to implement a reliability strategy.
Application of CAE Methods to Increase Efficiency in Powertrain DevelopmentSimulationX
The document describes efforts by Jaguar Land Rover, ZF, and ITI GmbH to develop a complete powertrain torsional system model using SimulationX to increase efficiency in powertrain development. A multi-body dynamics model of the engine is coupled to a torque converter damper and 8-speed automatic transmission model. Analysis of the model shows good correlation to test data and allows investigation of noise and vibration issues and optimization of modal placement early in the design process.
This document provides a theory and experimental procedure for demonstrating an undamped vibration absorber. The theory section explains how attaching an auxiliary mass-spring system to a vibrating object can reduce vibrations by extracting the energy that causes them. If the absorber's natural frequency matches the object's frequency, the object's amplitude can be reduced to zero. The experiment uses a beam with a motor to induce vibrations, and an absorber attached below to reduce the beam's amplitude at different motor speeds by adjusting the absorber's mass positions. The goal is to determine the absorber configuration that minimizes the beam's vibrations.
This document contains lecture notes on mechanical vibrations. It covers topics such as two degree of freedom systems, principal modes, double pendulums, torsional systems with damping, coupled systems, vibration absorbers, centrifugal pendulum absorbers, vibration isolators, and dampers. Examples of two degree of freedom systems include two masses connected by springs. Equations of motion are derived using mass and stiffness matrices. Torsional vibrations in shafts can be caused by inertia forces or shock loads. Centrifugal pendulum absorbers have a natural frequency that varies with rotational speed, making them well-suited for applications like engines.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Study of Wind Turbine based Variable Reluctance Generator using Hybrid FEMM-M...Yayah Zakaria
Based on exhaustive review of the state of the art of the electric generators fitted to Wind Energy Conversion System (WECS), this study is focused on an innovative machine that is a Variable Reluctance Generator (VRG). Indeed, its simple and rugged structure (low cost), its high torque at low speed (gearless), its fault-tolerance (lowest maintenance), allow it to be a potential candidate for a small wind power application at variable wind
speed. For better accuracy, a finite element model of a studied doubly salient VRG is developed using open source software FEMM to identify the electromagnetic characteristics such as linkage flux, torque or inductance versus rotor position and stator excitation. The obtained data are then transferred into look-up tables of MATLAB/Simulink to perform various simulations. Performance of the proposed wind power system is analyzed for several parameters and results are discussed.
Study of Wind Turbine based Variable Reluctance Generator using Hybrid FEMM-M...IJECEIAES
Based on exhaustive review of the state of the art of the electric generators fitted to Wind Energy Conversion System (WECS), this study is focused on an innovative machine that is a Variable Reluctance Generator (VRG). Indeed, its simple and rugged structure (low cost), its high torque at low speed (gearless), its fault-tolerance (lowest maintenance), allow it to be a potential candidate for a small wind power application at variable wind speed. For better accuracy, a finite element model of a studied doubly salient VRG is developed using open source software FEMM to identify the electromagnetic characteristics such as linkage flux, torque or inductance versus rotor position and stator excitation. The obtained data are then transferred into look-up tables of MATLAB/Simulink to perform various simulations. Performance of the proposed wind power system is analyzed for several parameters and results are discussed.
This document summarizes the design aspects of an active electromagnetic suspension system for automotive applications. Key points include:
- The system combines a brushless tubular permanent magnet actuator with a passive spring to provide active roll and pitch control for improved stability, safety and passenger comfort.
- Measurements of vehicle acceleration on a test track were used to derive static and dynamic specifications for the actuator, including a continuous force of 1 kN and peak force of 4 kN for roll control.
- The actuator must also be capable of providing variable damping equivalent to a passive damper, absorbing an average of 762 N of force from road vibrations.
- The proposed design aims to have a form factor compatible
This document discusses the design of an active electromagnetic suspension system for automotive applications. Key points:
- An active suspension system is proposed using a brushless tubular permanent magnet actuator in parallel with a passive spring. This provides additional stability during maneuvers like cornering and braking.
- Specifications for the actuator are derived based on measurements of forces during test drives. The actuator needs to produce peak forces of 4 kN and continuous forces of 1 kN to eliminate roll and pitch. It also needs to absorb road vibrations up to 2.05 kN.
- A quarter-car test setup is used to validate the improved performance of the active suspension system. Measurements show the roll angle is
This document discusses dimensioning a drive system, including:
1. The general steps of dimensioning including selecting the motor and frequency converter.
2. Common load types like constant torque, quadratic torque, and constant power loads.
3. How a motor's thermal loadability decreases at lower speeds for self-ventilated motors, but separate cooling allows overloading at low speeds.
Application of Numerical and Experimental Simulations for the Vibrating Syste...IJERD Editor
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Wartsila sp-a-id-4s-engines-c
1. [ MARINE / IN DETAIL ]
[MARINE/INDETAIL]
Engine dynamics and vibration control
AUTHORS : Hannu Tienhaara, Head of Calculation & Simulation, R&D, Wärtsilä in Finland
Heikki Mikonaho, Strength & Structural Dynamics, R&D, Wärtsilä in Finland
Fig. 1 – A Wärtsilä 8L46 engine with ABB TPL turbocharger.
The increasing demand for lowering
the noise and vibration levels of
engines has forced manufacturers to
make use of advanced analysis and
simulation tools.
In most cases, the practical means to
reduce vibration is simply to detune the
lowest natural frequencies away from the
main dynamic excitation frequencies.
When detuning natural frequencies, the
most effective course is to concentrate on
the heavy structures built on to the engine
and its mounting. A good example is the
turbocharger, because its influence on the
vibration system is very dominating due
to its relatively large mass (Figure 1).
In certain problematic situations, a
tuned mass damper can be used to change
the vibration system dramatically.
As regards reducing vibration on the
Wärtsilä 9L46 engine, a study ended
up with two different solutions: For the
current production engines, a new firing
order was introduced offering a better
distribution of the excitation forces at
certain harmonic orders. This solution
requires the use of a special balancing
device in order to cope with the increased
first order free couples. However, changing
the firing order on a 9-cylinder engine is
not a feasible solution for existing engines
already in the field. For these engines
the tuned mass damper was chosen as
being the most suitable solution.
A tuned mass damper is a device
whereby an additional mass is mounted
with flexible elements on the vibrating
machine. The damper is tuned in
such a way that its own vibration is
producing a counter force against the
main structure’s vibration. Normally a
damper is tuned to dampen a certain
natural frequency, but in the case of a
constant speed engine, it can also be
tuned to a specific excitation frequency.
The two biggest challenges in designing
and tuning this kind of a system are:
1)Handling a wide range of running
speeds and several natural frequencies
and mode shapes.
2)Making a reliable construction
capable of operating for thousands of
running hours without maintenance.
Dynamic system
The relationship between the excitation,
the structural properties, and the response
can be expressed as per the diagram in
Figure 2. The vibration response is a
result of the dynamic properties of the
structure and the excitation force.
A vibration system is normally
presented mathematically by the well-
known general equation of motion:
(1)
where M, C and K are matrices of mass,
damping and stiffness, f(t) is the vector
of applied force (excitation), and x(t) is
the vector of displacement (response)
and its time derivatives, velocity and
acceleration accordingly. The matrices
M, C and K represent the dynamic
characteristics of the structure. Reducing
vibration levels can be achieved by
modifying one or several of these
characteristics, or the excitation vector f(t).
The matrix M is not only the total
mass, but represents also the mass
distribution over the whole structure.
The same applies to the stiffness
matrix K. From the vibration point of
view, it may be very important where
the mass or stiffness is located.
C denotes the damping, which in
practice is not only a uniform number.
In real structures the damping normally
varies depending on the frequency and
mode shape, as well as on the location. In
complex structures like engines, several
different damping types can be found.
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2. WÄRTSILÄ TECHNICAL JOURNAL 02.2008
57indetail
Finally, there is the vector f(t)
representing the force or excitation vector.
Means of modifying the force vector
in order to reduce vibration response
can be, for example, a balancing device
where some additional forces are
included in the system, or changing the
firing order when the forces are applied
in a different order to the system.
Vibration analysis
In the vibration analysis of an engine
or a diesel generating set (genset), the
following parts can be included:
1) Eigenfrequency and mode shape analysis
2) Calculation and analysis of major
excitation forces
3) Dynamic response analysis.
Eigenfrequency analysis
Normally, the first step in making a
structural vibration analysis of a diesel
engine is a calculation of its natural
frequencies and mode shapes.
A typical calculated lowest torsion
mode is shown in Figure 3.
Excitations
The calculation and analysis of excitation
forces are an essential element in vibration
optimization. The major excitations caused
by gas and mass forces, taking into account
the firing sequence of the engine, are
calculated and analyzed. Modern multi-
body dynamics (MBD) simulation tools
offer an accurate and relatively fast way
of calculating the mechanical excitation
forces acting on the engine block.
The excitations of diesel engines are
periodic. For this reason, it is natural
to analyze the excitations as well as
the vibration measurements within
the frequency domain.
The main excitation sources of a medium
speed diesel engine can be categorized as
shown in Figure 4, [1]. The origin of mass
forces is the crank mechanism, which has
both rotating and oscillating components.
On the lowest integer harmonic
orders, the mass forces induce mainly
rigid body motions of the whole engine
structure. However, some bending of the
engine block due to mass forces, is also
visible, especially on long engines. The
gas forces resulting from the cylinder
pressure cause a torque variation at
each cylinder. This torque variation is
transferred to the engine block through
the main bearings and via the lateral force
Fig. 2 – Diagram of the relationship between excitation, structure and response.
Fig. 3 – Typical lowest natural mode shape of torsion of a Wärtsilä 8L46 engine.
Fig. 4 – The main categories of excitation forces.
Excitation
– Frequency, amplitude,
direction, location, etc.
Structural properties
– Natural frequencies, natural
mode shapes, damping
Vibration response
Amplitude, frequency, mode
Excitation type
Excitation
source Oscillating
Appearance
in a multi-
cylinder
engine block
Vibration at the
first harmonic order
Rigid body vibration
and bending
Vibration at lowest
full orders, mainly
orders 1 and 2
Rigid body, bending
and some torsion
- All harmonic orders,
including half orders
- Mainly torsion
based deflections
on the engine
SIMPLE ..................................................... COMPLEX
Main excitations of a 4-stroke engine
Gas forces
Cylinder pressureRotating
(Unbalance)
Mass forces
3. [ MARINE / IN DETAIL ]
[MARINE/INDETAIL]
Fig. 5 – Relative comparison of torsional excitations of a 9-cylinder engine
with two firing orders.
Vectorsumoftorsion
Harmonic order
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
1 - 2 - 4 - 6 - 8 - 9 - 7 - 5 - 3
1 - 7 - 4 - 2 - 8 - 6 - 3 - 9 - 5
Fig. 6 – Influence of an added spring-mass-damper system on the resonance
frequencies and response amplitudes of the main structure.
Fig. 7 – The prototype of the tuned mass damper.
of the piston against the cylinder liner.
When analyzing these excitations, it
is necessary to take into account, not
only the excitation strength at different
frequencies, but also the similarity of the
excitation mode and natural mode shapes
within the frequency range in question.
As regards gas-force-induced torsion
excitations, it is relatively easy to quickly
compare different firing orders by
means of a vector summation. Figure
5 shows the difference in torsion
excitations with two different firing
orders on a 9-cylinder engine.
Forced response analysis
When using MBD software to simulate
engine vibrations, the simulation model
itself performs the calculation of the
excitation forces and their application
on the correct locations in the model.
The analysis is done in a time domain,
normally using condensed models of
the structure.
The direct time integration method,
using Finite Element Software, is very time
consuming and often not feasible. Its most
important advantage is that it can take
the structural nonlinearities into account.
A linear analysis in a frequency domain
is fast and sufficiently accurate providing
that the FEM model is presenting the
structural characteristics reliably.
Tuned mass damper
The use of a passive tuned mass damper
is a known method for reducing
vibrations resulting from earthquakes
in high buildings. It has also been used
to eliminate vibration problems on ship
structures, for example, and to solve
different kinds of machinery vibration
problems, but not necessarily so much
for reducing diesel engine vibrations.
The designation “tuned mass damper”
refers to the construction, consisting of a
vibrating mass with a natural frequency,
tuned to the desired frequency. Figure
6 shows the principal effect of a tuned
mass damper. The device is also known
as a vibration absorber in situations
where the damping factor is very small,
such as when just a steel spring is used
without any additional damping.
The blue line shows the vibration
response of the main structure m0 due to
ground movement or applied force. It has
a natural frequency at frequency f0 where
the increased vibration amplitude can
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4. WÄRTSILÄ TECHNICAL JOURNAL 02.2008
59indetail
be seen. The red line shows the response
of the same main structure after adding
mass m1 to the system with the spring k1
and damping c1, as shown in the Figure.
When the damper is correctly tuned, it
can reduce vibrations dramatically within
the area of the resonance frequency.
From Figure 6 it can also be seen that
by adding a damper to the system, the
vibration of the main structure outside
the intended damping area increases.
This is one disadvantage of the damper,
which must be taken into account. One
must remember, particularly in the
case of medium speed diesel engines
where the main excitation frequencies
are spread over a wide frequency range,
that at some harmonic orders the
vibration level is increased by the damper.
However, with proper tuning of the mass,
stiffness and damping parameters, it is
possible to reduce this phenomenon.
As it has been clearly shown, the correct
dimensioning of the added mass m1, the
stiffness k1 as well as the damping c1,
is essential in order to achieve the best
possible damper performance. As a rule
of thumb, it can be considered that the
added mass required to achieve a proper
damping effect, is about 5% of the modal
mass of the vibration mode in question.
The spring coefficient k1 and the damping
factor c1 are then chosen so that the
damped natural frequency of the mass m1
will match the frequency to be dampened.
Engine vibration control by
using a tuned mass damper
Contrary to the above theoretical example,
in the case of a real engine, the problem
is somewhat more complicated. Firstly,
finding the correct parameters is not an
easy task when the engine has a wide range
of rotating speeds and several harmonic
orders exciting resonances. Secondly,
finding theoretically the best possible
location and direction for the damper
requires a thorough analysis of the system
using the finite element method. Thirdly,
actual structures usually consist of several
natural mode shapes that contribute to
excessive vibration levels. By choosing a
suitable direction for the damper, it is still
possible to have some influence on more
than one mode shape.
Damper development
The tuned mass damper developed
by Wärtsilä consists of vibrating mass
discs supported by steel springs. Both
are located, together with damping oil,
inside a cylindrical steel frame. All the
damper parameters, mass, stiffness and
damping, can be separately adjusted.
The damping coefficient is changed by
altering the oil flow inside the damper.
The damper is shown in Figure 7.
Vibration simulation and tuning
Comprehensive simulations were carried
out during the development of the mass
damper. The main parts of the engine
model were built in Ideas, and the meshing
was done in Hypermesh. The engine
vibrations with the tuned mass damper
were simulated using Abaqus and Modysol
software.
Modysol is a software package developed
by VTT, the Technical Research Center
of Finland.
The dynamic excitation forces were
calculated using an in-house software called
Dynex.
Optimizing the location of the damper
is essential to minimizing its effective mass.
After several simulations it was noticed
that, in the case of an in-line Wärtsilä
46 engine, the top of the turbocharger
is the most feasible location in order to
minimize the required vibrating mass.
A 9-cylinder four-stroke engine with
a firing order of 1-2-4-6-8-9-7-5-3,
gives high excitation forces for the first
torsion mode at harmonic orders 4.0
and 5.0, as shown in Figure 8. Between
those excitations, the harmonic order
4.5, which corresponds to the firing
frequency, gives a strong rolling excitation.
With the damper mounted so that the
movement of the effective mass is in the
engine transversal direction, it is not very
efficient in damping the vibrations in the
vertical direction. According to vibration
measurements, the vertical vibration is,
however, not very critical in this case.
It is clear, therefore, that there are two
possibilities for tuning the damper: to
concentrate on the 1st
torsion mode at
29 Hz, or on the horizontal bending mode
at 42 Hz. The former option was proven to
be the better one, and was finally chosen.
The same principles are used in the
tuning of the damper for the Wärtsilä 8L46
engine. The most significant excitations are
at the harmonic orders 3.5 and 4.5, as well
as at the order 4.0, which corresponds to
the firing frequency of an 8-cylinder engine.
Fig. 9 – A tuned mass damper mounted
on a turbocharger.
Fig. 8 – The most critical natural frequencies and excitations for
the 1
st
torsion mode on a Wärtsilä 9L46 engine with a firing order
of 1-2-4-6-8-9-7-5-3.
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
Natural frequencies
5. [ MARINE / IN DETAIL ]
[MARINE/INDETAIL]
Fig. 10 – Reduction of vibration levels on the turbocharger using the tuned
mass damper. Wärtsilä 9L46 engine.
Overall RMS (2–200 Hz): 80.2 mm/s
RMSVelocity[mm/s]RMSVelocity[mm/s]RMSVelocity[mm/s]
Frequency [Hz]
Frequency [Hz]
Frequency [Hz]
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
0 20 40 60 80 100
0 20 40 60 80 100
0 20 40 60 80 100
LONGITUDINAL
TRANSVERSAL
VERTICAL
Overall RMS (2–200 Hz): 66.6 mm/s
Overall RMS (2–200 Hz): 63.2 mm/s
Fig. 11 – Comparison of overall vibration levels on a Wärtsilä 9L46 engine’s
turbocharger and silencer with and without a mass damper.
120
100
80
60
40
20
0
r.m.s.velocity[mm/s]
Without damper
With damper
TCcompressor
L
TCcompressor
T
TCcompressor
V
TC
silencer
L
TC
silencer
T
TC
silencer
V
Field testing and results
In addition to comprehensive simulations
on both the 8-cylinder and 9-cylinder
Wärtsilä 46 engines, the mass damper
has passed full scale field testing on
real engines, as shown in Figure 9.
The field testing was carried out in order
to verify the functionality of the damper
with the optimum tuning parameters,
as well as to assess the performance over
long term operation. The reduction of
the vibration levels on the turbocharger
compressor casing are shown in Figure
10. From these measurements it can be
seen that with the damper well tuned,
the vibration can be reduced at more
than one harmonic order. In this case,
vibrations at all the three major excitation
harmonics are reduced in both transversal
and longitudinal directions. Vibration is
increased only at the harmonic order 4.0
in the vertical direction, but also there the
overall vibration level is slightly reduced.
This can be seen in Figure 11 where L, T
and V denote the longitudinal, transversal
and vertical directions, respectively.
Figure 12 indicates the overall r.m.s.
velocity vibration levels on the same
turbocharger during the engine sweep run.
The running speed was changed from 360
up to 500 rpm with a propeller loading.
Another example, shown in Figures
13 and 14, is taken from the vibration
test results of an 8-cylinder engine.
The figures show the results, with and
without the tuned mass damper, on
the engine’s foot, charge air cooler,
and turbocharger (Figure 14).
At the writing of this article, altogether
15 dampers have been delivered. The
cumulative running hours for these
dampers is 82,000 h. However, some of
these dampers have already accumulated
12,000 running hours without any service
operation.
CONCLUSION
When optimizing the vibration
performance of a medium speed diesel
engine, as many different contributing
aspects as possible should be taken into
account. A thorough vibration analysis
includes the eigenfrequency and mode
shape analysis, the analysis of excitation
forces, and finally, as a combination, the
dynamic forced response simulation
The final result is always a compromise
between many different criteria. For
example, the firing order giving the
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6. WÄRTSILÄ TECHNICAL JOURNAL 02.2008
61indetail
Without damper
With damper
100
90
80
70
60
50
40
30
20
10
0
20 25 30 35 40 45 50
r.m.s.velocity[mm/s]
smallest free forces is most probably not
the best one from the point of view of the
internal bending moment or torsional
vibration. Similarly, the stiffening of the
structure in order to move one natural
frequency away from a critical excitation,
may create another natural frequency
in another excitation frequency area.
When it is not possible to tune
the natural frequencies of the engine
structure properly to avoid vibrations,
and when modifying the excitation
forces is not feasible, a tuned mass
damper can be a good solution.
An accurate prediction of the
performance of a tuned mass damper
requires special simulation tools,
making it possible to include the local
damping within the simulation model.
On the basis of the simulations and
tests described in this article, the best
and most effective location for the tuned
mass damper is on the turbocharger. At
that location the displacement amplitudes
are normally much higher than on other
parts of the engine, which is essential
for the damper to work efficiently.
When the damper is properly tuned,
it can reduce vibration levels at more
than one excitation frequency. In the
cases presented here, considerable
vibration reduction was achieved at
three major excitation harmonics.
NOMENCLATURE
C Damping matrix
M Mass matrix
K Stiffness matrix
f(t) Force vector
x(t) Displacement vector
L Longitudinal
T Transversal
V Vertical
c0 Damping of the main structure
mounting
c1 Damping of the damper mass mounting
k0 Stiffness of the main structure
mounting
k1 Stiffness of the damper mass mounting
m0 Mass of the main structure
m1 Added damper mass
r.m.s. Root Mean Square
REFERENCES
[1] TIENHAARA, HANNU, “Guidelines for
engine dynamics and vibration”, Wärtsilä
Marine News, 1/2004
Fig. 12 – Vibration on the turbocharger in the vertical direction.
Wärtsilä 9L46 engine.
Fig. 14 – Vibration results on an 8-cylinder engine’s turbocharger
with and without a damper.
Fig. 13 – Vibration results on an 8-cylinder engine with and without a damper.
r.m.s.velocity[mm/s]
30
25
20
15
10
5
0
Engine
foot L
Engine
foot T
Engine
foot V
Charge
air cooler
Charge
air cooler
Charge
air cooler
Without damper
With damper
Without damper
With damper
120
100
80
60
40
20
0
r.m.s.velocity[mm/s]
Turbo charger L Turbo charger T Turbo charger V