Basic Theory And Research Of The Working Process In A Twin-rotor Piston Engine

In pace with the development of modern industry, there will be more needs for new high-compact transportations, e.g. helicopter, one-man flight vehicle, aerocar and unmanned air vehicles. And these equipments all require high mobility. Besides, as the chief power take-off, engine need to be more focused on economical aspect of fuels facing with the situation of increasingly exhaustion of oil resource, the rising of fuel’s price and severe requirement on discharge. Light weight engine not only accelerate the mobility of transportation, but also it can reduce oil consumption and improve discharging function. The lightweight engine is realized by improving the structures, materials and manufacturing engineering. The main purpose is to promote the engine’s power density, namely, the engine’s rising power index or power weight index. Because of mechanism’s limitation, traditional reciprocating piston engine has some inherent defects and there has few possibilities to increase its power density. Although Triangle-roter Piston Engine(TRPE) has higher power density and bigger power weight index, its inherent structural defects and sealing problem made TRPE has a low degree of fuel consumption index and stability. At the start of international engine’s technology innovation, we should seize the opportunity and develop the new type engine with combined advantages of reciprocating piston engine’s stability and Triangle-Rotor Piston Engine’s high power density.The motivation of the research is originated from the National Administration Key Research Project. The basis of the research relies on the improvement and innovation of differential pace pattern engine labeled Twin-rotor Pistor Engine(TRPE)which overcame some shortages of old engines and reserve some traditional engines’ mature designing experience. Twin-rotor Pistor Engine is equipped with high capacitiy factor which largely improve the degree of light quantization. TREP is prepared with high power density and can improve the engine’s light weigh degree in theory. Some basic theories in relation to this engine are under discussion showing in this thesis. The purpose is to build a strong and significant theoretical framework into the advanced research and production of sample engine. In one word, the basic research ideas are presented as follow:(1) Paper has studied the overall structure of the TRPE and made a detailed analysis on the energy transformation components and differentials driving components. It has analysed the working principles of TRPR and studied the four strokes circulating process. The characteristics of zero dimensional model and Multidimensional model have been introduced. Focused on TRPE’s working mechanization, the simulating strategy of combustion model has been analyse. TRPE bears three advantages in the purpose of acquiring high capacity power comparing to other traditional engines through innovative structure design: when the principal axis circulates one time, the engine works eight times. Also, at the any time, there are two working channels with well-distributed spaces are in the working procedure. Secondly, the characteristics are the machinery design of symmetry and balance, pure torque outputting engine and fabulous transmitting features. Last but not the least important, the finish of the engine circulation doesn’t need complex distribution equipment leading to the decrease of its weight.(2)The analysis of TRPE’s thermodynamics has been done. Based on the hypothesis, the conservation of energy law and quality law, the ideal gas equation and other basic thermodynamics differential equation have been built. The working process in the engine’s simple stroke has been studied and the whole process has been divided into six stages and studied. They are compression, burning, expansion, exhausting, compression-exhausting and admission. The differential equation related binding conditions have been built and the zero-dimensional model has been finally produced.(3)The solving ways of TRPE zero-dimensional model have been introduced. Based on the pre-productioned sample’s performance parameter, initial parameter of artificial model has been built. The state has been transferred in advantage of stateflow and the time sequence discrimination has been realized, so the artificial model of bordering condition has been built. Taken advantage of the solving way and based on MATLAB/Stimulink, the subject artificial model of zero-dimensional model has been produced; also compression, burning and other six stages artificial models have been built. Finally, the artificial calculation of zero-dimensional model has been finished. Based on above processes, the changing regularities of working medium’s state parameters, e.g. quality, temperature, pressure etc., in the stroke have been worked out. In theory, it is possible to obtain numerical answer of engine’s power density index and rising power. It scientifically has proved that TREP is a high power density engine.(4) Numerical simulation of multi-dimensional modal on TREP has been done by utilizing CFD technology. The grid division of the constant changing stroke has been done by making use of mobile web technology. The basic governing equation of multi-dimensional modal has been built based on some basic assumptions. Turbulent model used in flow field of the simulated stroke has been studied. Also, burning model, discharging model, initial condition and bordering condition have been analyzed. The working process of engine has been numerical modeled by use of FLUENT. The changing regularities of working medium flow in the inner stroke have been obtained. The design of annular cylinder has been proved to be more favorable to burning. Also, by comparison with the calculating result of zero-dimensional modal theory, the rationality has been proven between each other and two models have been proven to be useful.(5)The working characteristics of TREP’s differential driving components have been studied. The basic kinetics parameter of differential driving components has been defined. The main components’ energy and moment balance equation have been built by using vector mechanics analytics. The Matrix mathematical model related to dynamic statics analysis of differential driving components has been built. Based on kinesiology analysis, the basic attribute of each component has been given. The barycenter characteristics of motion have been found by using MATLAB. And then, receiving power regularity of main component has been found. In the engineering design stage, the given dynamic load fluctuation can be used to instruct the parameters design of differential driving components which include stiffness, intensity and fatigue.(6) The composition of TREP’s electronic governing system has been studied. Further, the governing strategy of engine’s electronic governing system has been discussed. So the basic sample machine has been produced. The differential moving characteristics of TREP have been tested. The problems, e.g. the sealing function of the sealing ring, lubrication, the working condition of cooling oil-way, all have been studied and proven. These studies have been of great significance to TREP’s engineering development.