SIMULATION OF PNEUMATIC MOTOR USED IN PNEUMOBILE

Abstract

One of the alternative powertrain systems of cars, commercial vehicles and mobile machines are hybrid drives with pneumatic motors for compressed air. This paper presents a mathematical model and the results of simulation calculations of piston pneumatic motor. Mathematical model was based on the fundamental principles of mechanics, thermodynamics and rights of airflow. For simulation model parameterization, prototype of such engine was built and installed on dedicated test stand. Performed experimental research allowed achieving values of coefficients and components characteristics used for model estimation. One of the important tasks of this study was to create the control system of the compressed-air supplied engine. For this purpose an appropriate pneumatic and electronic component were selected and also an algorithm was created which would facilitate changing of the engine settings in order to obtain the best performance. Using elaborated simulation model, series of calculation were performed for different parameters of pneumatic motor, like cylinders diameter and stroke, length of the crank, compressed air pressure and valves size. A lot of attention was devoted to determine the influence of control system settings, such as valves opening and closing in reaction to crankshaft position, on motor properties. When discussing the results of calculations considerable attention was paid to the power, torque and efficiency values. To illustrate performance of designed engine, simplified model of light vehicle was used to calculate possible to achieve acceleration, velocity and travel distance.