To study the economic advantages of hydrogen internal combustion engine, an experimen- tal study was carried out using a 2.0 L port fuel-injected （PFI） hydrogen internal combustion engine. Influences of fuel-air equ...To study the economic advantages of hydrogen internal combustion engine, an experimen- tal study was carried out using a 2.0 L port fuel-injected （PFI） hydrogen internal combustion engine. Influences of fuel-air equivalence ratio φ, speed, and ignition advance angle on heat efficiency were determined. Test results showed that indicated thermal efficiency （ ITE ） firstly increased with fuel- air equivalence ratio, achieved the maximum value of 40. 4% （ φ = 0.3 ）, and then decreased when was more than 0. 3. ITE increased as speed rises. Mechanical efficiency increased as fuel-air equiva- lence ratio increased, whereas mechanical efficiency decreased as speed increased, with maximum mechanical efficiency reaching 90%. Brake thermal efficiency （BTE） was influenced by ITE and me- chanical efficiency, at the maximum value of 35% （φ =0.5, 2 000 r/min）. The optimal ignition ad- vance angle of each condition resulting in the maximum BTE was also studied. With increasing fuel- air equivalence ratio, the optimal ignition angle became closer to the top dead center （ TDC ）. The test results and the conclusions exhibited a guiding role on hydrogen internal combustion engine opti- mization.展开更多
With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acous...With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acoustic transfer vector（ATV） technique and coupled boundary element model and finite element model （BEM-FEM） approach.Analyses of vibration exciting loads,computing structural dynamic characteristics and dynamic responses have led to theoretical results,which are tested on an L6 diesel engine to validate this proposed technique in engineering practice.展开更多
Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide req...Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2 D drafting, 3 D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work.展开更多
Friction and lubrication simulation analysis of internal combustion engine bearings are studied. A series of software implementary precepts for mathematical modeling, to analytic calculating and realizing simulation o...Friction and lubrication simulation analysis of internal combustion engine bearings are studied. A series of software implementary precepts for mathematical modeling, to analytic calculating and realizing simulation outcome are brought forward. As a dynamic simulating technique is introduced into the process of engine bearing design, simulation models of the oil film are built and the emulational analysis of the shaft center track is carried out. A software program package “Engine Bearing Friction and Lubrication Dynamic Simulation System” is developed to realize the real time simulation of the working status of bearing during the design process. Through developing virtualized products, the defects of the product design can be found in time and improve the products at once. Thus the purpose of predicting and controlling the cost, quality and design period of the products can be achieved.展开更多
The structure, separation principle and feasibility research for a new type of vehicle air filter called the high speed rotary positive air filter were described. The analysis of the experimental data showed that the ...The structure, separation principle and feasibility research for a new type of vehicle air filter called the high speed rotary positive air filter were described. The analysis of the experimental data showed that the principle and structure of it were feasible and it possessed high separation efficiency and great self cleaning ability. Compared with the conventional air filter it also has lower air intake loss. So it is worth further practical research.展开更多
A contact bolt model is proposed as a new modeling technique to investigate the complex structure with bolted joints for modal analysis and compared with the coupled bolt model, and the test results are given. Among t...A contact bolt model is proposed as a new modeling technique to investigate the complex structure with bolted joints for modal analysis and compared with the coupled bolt model, and the test results are given. Among these models, the coupled bolt model provides the best accurate responses compared with the experimental results. The contact bolt model shows the best effectiveness and usefulness in view of operational time. The bolt models proposed in this study are adopted for a dynamic characteristic analysis of a large diesel engine consisting of several parts which are connected by many bolts. The dynamic behavior of the entire engine structure was investigated by experiment. The coupled bolt model and the contact bolt model were applied to model the assembly of engine with high preload. The experimental results are in good agreement with the finite element method （FEM） results. Compared with the other models, the contact bolt model presented in this paper is more effective and useful in view of operational time and experience of analysts.展开更多
To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generatio...To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generation： the initial mesh generation and the mesh pre-treatment. In the second step （pre-treatment）, the connectivity of those cells is generated by a new algorithm added to the KIVA-3V code after the initial mesh generated. In dynamic mesh management phase, a new rezoning algorithm is developed and the basic principle is that the rezoning starts from the moving part. The movement of the adjustment is treated as an ＂earth quake wave＂ propagating to the surrounding vertexes. The amount of coordinate adjustment of the surrounding vertexes is determined by the movement of the epicenter and the distance between the vertexes and the ＂epicenter＂. Finally, a real IC engine mesh is generated and managed aceording to the new method. It gives a new theory and a new method for creating and managing the mesh in IC engine.展开更多
基金Supported by the National Natural Science Foundation of China(51276019)
文摘To study the economic advantages of hydrogen internal combustion engine, an experimen- tal study was carried out using a 2.0 L port fuel-injected （PFI） hydrogen internal combustion engine. Influences of fuel-air equivalence ratio φ, speed, and ignition advance angle on heat efficiency were determined. Test results showed that indicated thermal efficiency （ ITE ） firstly increased with fuel- air equivalence ratio, achieved the maximum value of 40. 4% （ φ = 0.3 ）, and then decreased when was more than 0. 3. ITE increased as speed rises. Mechanical efficiency increased as fuel-air equiva- lence ratio increased, whereas mechanical efficiency decreased as speed increased, with maximum mechanical efficiency reaching 90%. Brake thermal efficiency （BTE） was influenced by ITE and me- chanical efficiency, at the maximum value of 35% （φ =0.5, 2 000 r/min）. The optimal ignition ad- vance angle of each condition resulting in the maximum BTE was also studied. With increasing fuel- air equivalence ratio, the optimal ignition angle became closer to the top dead center （ TDC ）. The test results and the conclusions exhibited a guiding role on hydrogen internal combustion engine opti- mization.
基金Sponsored by the National Natural Science Foundation of China (50505047)Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acoustic transfer vector（ATV） technique and coupled boundary element model and finite element model （BEM-FEM） approach.Analyses of vibration exciting loads,computing structural dynamic characteristics and dynamic responses have led to theoretical results,which are tested on an L6 diesel engine to validate this proposed technique in engineering practice.
文摘Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2 D drafting, 3 D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work.
文摘Friction and lubrication simulation analysis of internal combustion engine bearings are studied. A series of software implementary precepts for mathematical modeling, to analytic calculating and realizing simulation outcome are brought forward. As a dynamic simulating technique is introduced into the process of engine bearing design, simulation models of the oil film are built and the emulational analysis of the shaft center track is carried out. A software program package “Engine Bearing Friction and Lubrication Dynamic Simulation System” is developed to realize the real time simulation of the working status of bearing during the design process. Through developing virtualized products, the defects of the product design can be found in time and improve the products at once. Thus the purpose of predicting and controlling the cost, quality and design period of the products can be achieved.
文摘The structure, separation principle and feasibility research for a new type of vehicle air filter called the high speed rotary positive air filter were described. The analysis of the experimental data showed that the principle and structure of it were feasible and it possessed high separation efficiency and great self cleaning ability. Compared with the conventional air filter it also has lower air intake loss. So it is worth further practical research.
基金Sponsored by the Ministerial Level Foundation(40402020105)
文摘A contact bolt model is proposed as a new modeling technique to investigate the complex structure with bolted joints for modal analysis and compared with the coupled bolt model, and the test results are given. Among these models, the coupled bolt model provides the best accurate responses compared with the experimental results. The contact bolt model shows the best effectiveness and usefulness in view of operational time. The bolt models proposed in this study are adopted for a dynamic characteristic analysis of a large diesel engine consisting of several parts which are connected by many bolts. The dynamic behavior of the entire engine structure was investigated by experiment. The coupled bolt model and the contact bolt model were applied to model the assembly of engine with high preload. The experimental results are in good agreement with the finite element method （FEM） results. Compared with the other models, the contact bolt model presented in this paper is more effective and useful in view of operational time and experience of analysts.
基金Sponsored by the Ministerial Level Foundation (1003)Beijing Municipal Commission of Education Foundation (KM200710016013)
文摘To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generation： the initial mesh generation and the mesh pre-treatment. In the second step （pre-treatment）, the connectivity of those cells is generated by a new algorithm added to the KIVA-3V code after the initial mesh generated. In dynamic mesh management phase, a new rezoning algorithm is developed and the basic principle is that the rezoning starts from the moving part. The movement of the adjustment is treated as an ＂earth quake wave＂ propagating to the surrounding vertexes. The amount of coordinate adjustment of the surrounding vertexes is determined by the movement of the epicenter and the distance between the vertexes and the ＂epicenter＂. Finally, a real IC engine mesh is generated and managed aceording to the new method. It gives a new theory and a new method for creating and managing the mesh in IC engine.
