Enhancement of Heat transfer of Cylinder liner and Coolant jacket for High powered Diesel engine

Abstract

The cooling system of an Armoured Fighting Vehicles (AFV) is critical and complex when compared to other automobiles mainly because of the severe temperature and dust conditions in which they operate. For proper working of the engine, it is very important that the engine be maintained at optimum temperature during its operation to have desired performance levels. Usually high powered engines employ water cooled cooling systems with compact radiators. Also the cooling system in AFV Engine is very critical as the air space available is very less. This is due to the fact that the engine is enclosed in a compartment where the ram air due to vehicle movement cannot be used to cool the radiators. Hence any small improvement in the heat transfer improves the performance of the engine. The main aim of the study is to enhance the heat transfer between the engine liner and the coolant for AFV engines. The heat transfer rate is enhanced by modifications on the surface of the liner coolant interaction with an aim to induce turbulence in the coolant flow through the jacket. For each modification, the heat transfer coefficient is found out through CFD analysis in Ansys Fluent. The combustion temperatures and heat transfer coefficients obtained using simulation software AVL BOOST® were used to calculate the wall temperature of liner. Simulations on modified geometry of liner walls yielded up to a maximum of 18% improvement in heat transfer which is very significant.