Air Sensing Viscous Fan Drive Performance on Charge Air Cooled Engines

Air sensing viscous fan drives were tested on water to air and air to air aftercooled engines to evaluate the correlation between drive bimetal and radiator inlet coolant temperature. The fan drives were maintained in the disengaged mode and bimetal and radiator coolant inlet temperatures were recorded for different ambient temperatures* ram air conditions and engine loads. The results indicate that air sensing viscous fan drives successfully track the radiator coolant temperature and with the proper selection of drive calibration viscous fan drives provide a simple acceptable method of controlling engine coolant temperatures.