Search Results

MRF method is commonly used for predicting cooling performance to design vehicle engine cooling systems. Especially, the practical prediction of the cooling fan performance is one of the important issues. In the design phase of the vehicle development, combinations of multiple parameters are generally examined. Therefore, the steady RANS coupled with MRF method is indispensable. However, unfortunately, the current method does not always give enough accuracy to practical vehicle design. Thus, this paper describes that the method to determine adequate MRF-region to predict the fan performance in practical accuracy.

Recently, the evaluation of the thermal environment of an engine compartment has become more difficult because of the increased employment and installation of turbochargers. This paper proposes a new prediction model of the momentum source for the turbine of a turbocharger, which is applicable to three-dimensional thermal fluid analyses of vehicle exhaust systems during the actual vehicle development phase. Taking the computational cost into account, the fluid force given by the turbine blades is imitated by adding an external source term to the Navier-Stokes equations corresponding to the optional domain without the computational grids of the actual blades. The mass flow rate through the turbine, blade angle, and number of blade revolutions are used as input data, and then the source is calculated to satisfy the law of the conservation of angular momentum.