Use of a Pressure-Based Technique for Evaluating the Aerodynamics of Vehicle Cooling Systems

A pressure-based technique has been developed for the purpose of radiator cooling airflow measurement. The technique was effectively utilised to quantify the local time-averaged air velocity through radiator cores in a small wind tunnel. The pressure difference indicated by the technique was found to be a function of the normal component of the air velocity. This paper describes the development and use of the technique which is compact, robust and non-intrusive. By applying this technique, the airflow distribution across the radiator face has been measured for a complete vehicle in an aerodynamic wind tunnel and in an environmental chamber. Results are compared for the different test environments. The influence of airflow distribution on the Specific Dissipation (a parameter used for evaluating radiator cooling performance) is examined and results for propeller-based methods and pressure-based methods are compared. It is found that the pressure-based technique has given reliable results and can be a practical tool for use in evaluating the aerodynamics of vehicle cooling systems. In addition, this study also reveals a considerable lack of uniformity across the radiator front face of a typical passenger vehicle, inefficient use of the radiator core heat-transfer area with consequent.