Optimization of size of vehicle and flow domain for underhood airflow simulation

摘要

The sensitivity of the size of a model vehicle and the flow domain to the flowrate of air through the radiator has been systematically investigated. The sizes of the upstream flow domain in the x, y and z directions are determined by the front flow domain size, the top flow domain size and the side flow domain size respectively. As the size of the front, top or side domain falls below some critical value, the underhood air flowrate dramatically increases. The increase depends on the size of the front flow domain. Therefore, the front, top or side flow domain size significantly affects the underhood air flowrate only when the front, top or side domain is less than a specific length. Graphical results can be easily used to determine the size of the vehicle model and the flow domain that is required to underhood air flow simulation. Finally, the simulated vehicle flow domain sizes are compared with experimentally determined values. The comparison shows that the computed air flowrate through the radiator for the recommended vehicle and flow domain size agrees closely with the test data.