Downstream Blockage Corrections of Automotive Cooling Fan Module Performance

A novel, simple and rapid method for predicting the performance effects of blockage downstream of an automotive cooling fan is presented. Fans are often tested without downstream blockage and, thus, the performance is considerably different when the fan is mounted in a vehicle as part of a cooling system. An easy to use tool is needed that can quickly predict fan performance modifiers.

The suggested approach is able to predict the significant effects of a blockage behind the fan. Two fans were analyzed with this new method. Comparison charts between tests and predictions showed good agreement over a range of blockage distances. Based on the results the method is considered beneficial for initial design procedures. Although the agreement was poorer at very close separation distances such small gaps are less commonly utilized in practice. Further work is needed to include those distances in the present model.