CDL Thd-VKM: Heat Transfer in Inlet- and Exhaustports of Cylinderheads

With simulation tools in internal combustion engine development facing constant demands for increased accuracy, there is also a requirement for heat transfer figures to be calculated in greater detail. Heat transfer is an important boundary condition in engine operation, particularly for calculating the stress exerted on components and for computing the gas exchange. To determine the boundary conditions for such calculations the heat transfer coefficient will be used. The investigations are based on tests carried out on a steady flow test bed and an engine test bed. In addition to the measurement-based studies, the 3D flow simulation was also used to determine the heat transfer. In the steady flow tests, the measurement-based heat transfer coefficients were found from global heat transfer on the basis of thermal balance, and from simultaneous measurements of local heat flow rates. For the unsteady flow tests during real engine operation, measurement conditions meant that only local readings for the heat flow could be obtained. With the results of the experimental and the computer-based investigations modified equations has been developed for the inlet and outlet system seperated for the port region and the valve region.