Experimental Evaluation of Fans Used in an Automotive Engine Cooling System Using Hot-Wire Anemometer

Engine cooling system plays a major role in performance of vehicle engine، in which the radiator and the fan are the main components. In this article، the performance of two fans with different characteristics has been appraised within an engine cooling system. For this purpose، performance characteristics curves of both fans، including، static pressure and total pressure against flow rate have been generated. Then a test rig، similar to that of an engine''s cooling system، was set up for the fan and the radiator. Subsequently the air flow rate and Radiator''s inlet flow distribution have been measured precisely under working conditions using hot wire anemometer. also، the inlet airflow pattern was analyzed. Results reveal that intersection point of the system resistance curve and static pressure curve of the fans، do not represent the actual and true values of flow rate of the fans. However the actual flow rate is less than those anticipated. Then، some modifications were made to the entrance of one of the fans and it''s shroud، and similar tests have been performed. Although the test results after modification showed more uniformity in the flow towards the radiator، the increase of flow rate was minimal in the cooling system. Also، road tests of the vehicle did not represent much improvement on the performance of the cooling system.