Search Results

A numerical simulation program for the design of the cooling air duct and the cooling system of vehicles for stationary operating conditions is introduced. This program allows the simulation of interactions with the system environment resp. an air conditioning. Hot recirculations of air in the front part of the car and the inhomogenious flow through the heat exchangers radiator and condensor in their affects on the heat transfer capacity are simulated. The power demand of the fan, the water pump and the compressor is taken into account for calculating the heat flow from the engine into the cooling water.

The noise emission of cruising vehicles essentially consists of tire/road noise, drivetrain noise (engine with intake and exhaust system, transmission and driving axle) and aerodynamic noise due to the flow around bodywork, chassis, wheels and cooling air flow (fan). Engines and drivetrains have become quieter due to many man-years of engineering attention and tire noise has also been reduced - at least the noise reaching the passenger compartment. Consequently, the aerodynamic noise of ground vehicles has become dominant at driving speeds above 100 kph both in interior and exterior noise. In order to determine the contribution of aerodynamic noise to the overall noise, measurements are carried out more and more in specially equipped automotive wind tunnels.