MODELING AND SIMULATION OF HEAT TRANSFER IN TURBOCHARGED DIESEL ENGINES

Heat transfer modeling, as an integral part of numerical studies of internal combustion engines, is meant to help a manufacturer to enhance the engine performance by accurate prediction of thermal conditions, to make sure that the conditions doesn't cause increased emissions, and to analyze thermal stress limits of cylinder materials. The solution of heat transfer phenomena in turbo charged diesel engines is a very challenging task considering the number of systems (reciprocator engine and its components compressor, intercooler, intake manifold, turbine, exhaust manifold, coolant subsystem, lubricant oil subsystem), the different heat transfer mechanisms (conduction, convection and radiation) and the quick and unsteady changes inside the cylinder that take place at the same time. In paper are presented simulation results with application of programing software Matlab for the convective heat transfer from gas to cylinder wall, gas pressure and temperature for engine speeds 1200rpm and 1800 rpm as a function of crank angle for Commins turbocharged diesel engine type N-14. Radiation heat transfer, apart from convection, is an important mode of heat transfer in diesel engines. Also in the paper is presented a method for calculation of radiative heat flux distribution on the walls of the combustion chamber has been presented through three mods: two Annands models and adiabatic flame model.