In heat exchanger (HX) performance analysis, it is being assumed that the airflow entering the HX has a uniform velocity distribution. However, in reality, it is not the case. The airflow distribution is getting disturbed due to the presence of blockage in the airflow path and design of flow circuit in the HX. Uniformity index is an indicator which defines how uniformly the airflow is distributed on the HX  face. The objective of this work is to analyze uniformity index with horizontal and vertical type blockages ahead of the HX using computational fluid dynamics (CFD) tool. A good agreement between the predicted and measured velocity patterns over HX (radiator) validates the present computational methodology. A total number of 45 iterations are carried out with different parameters like blockage area and ram air speed. It is observed that uniformity index is better with horizontal type blockage compared to the vertical one. In addition to this, an empirical equation has been proposed to predict the uniformity index with respect to blockage type and area under varying air speed. Finally, these observations can serve as a design guideline in improving the HX performance with reference to airflow distribution.

heat exchanger, airflow distribution, engine cooling system, radiator, blockage.