Mathematical Modelling of Operating Processes in the Pneumatic Engine of the Car

The article presents studies of the operating process of the pneumatic engine, that can be installed on small vehicles as main or auxiliary power generating system. The aim is to assess the possibility of converting an internal combustion engine into a pneumatic engine capable of moving a vehicle with a small mass in urban settings with dense traffic flows using mathematical modelling. The behaviour in the operating processes of the engine under study has been performed by the computational method and verified experimentally at the installation created in the laboratory of the ICE department in Kharkiv National Automobile and Highway University. The computational technique in question differs from the existing ones because it is based on a dynamic model of an internal combustion engine. The developed pneumatic engine was mounted on the stand for determining its power, developed torque, compressed air consumption, pressure in its cylinders and the temperature of heating the engine. The inlet pressure ranged from 0.6 to 1.1 MPa. The results of testing the pneumatic engine showed that when using a spool-type air distributor without heating, it could reach a rate power of N_е = 6.22 kW with a specific flow rate of compressed air g_е = 91.45 kg/(kW ∙ h). A comparison of the calculated «Р-V diagram» with the diagram obtained experimentally with corresponding parameters of pressure and temperature at the inlet to the sleeve valve has been performed. The difference in the results of theoretical and experimental studies is less than 5%.