FURTHER STUDIES ON AUTOMOBILE FANS.

Cases of automobile cooling fans failing at speeds over 3000 rpm after a fairly short duration of operation motivated the investigation on the response of fan blades. Experimental work was conducted to determine the air thrust and the torque needed to drive the fan at different speeds. Strains on the surface of the blade were also recorded with the help of a multichannel strain measuring bridge and slip ring unit. In this paper the analytical behaviour of the fan is predicted by treating it as a twisted plate clamped at one end subjected to both stretching and flexure.