Research on Improvement of Cooling Efficiency of Two-Stroke Engines Using the Telemetric System for Measuring the Piston Temperature

Abstract

In this paper we propose a method for improving the cooling efficiency of air-cooled engines using heat-transfer enhancement on cooling surface of cylinders using turbulators. The turbulators are made in the form of round protrusions on the surface of the fins of the cylinders' cooling jacket perpendicular to the flow of cooling air. The eddy zones that occur behind these protrusions serve as a source of additional turbulization and contribute to the heat-transfer enhancement. The study on the effect of turbulators on improvement of the cooling effectiveness is based on the use of the thermometering of the piston method using a telemetry system of measurement with an optic communication channel. In this experiment, direct thermometering of the piston is performed and at the same time complementary errors related to the distortion of heat exchange on the cooling surfaces of engine cylinder that occur when the temperature of the engine cylinder fins is directly measured at different points are excluded. Comparative tests of a stock and prototype engine with a cooling jacket with turbulators showed a reducing temperature from 3 to 8 degrees at various points of the piston, which reduces the overall level of its high-heat state, allows for abandoning the labor-intensive process of alitizing and it cuts the engine cost.  The application of engine cooling efficiency based on heat-transfer enhancement using turbulators can be used to improve the operating reliability of motor-cycle engines and modern air-cooled drones, which can further reduce the noise factor of these vehicles.