Stress analysis of axial flow cooling fans

Abstract

Tests on automobile radiator cooling fans of three types of construction pressed out from sheets are reported. The blades of the fans are treated as twisted (from tip to root) cantilever beams (fixed at root) for the purpose of analysis. The effects of centrifugal force, driving torque, and the axial thrust over the blade due to air flow are taken into account. Air flow measurements are obtained using a pitot-static probe. The input power for various speeds is also recorded. The stress values are verified with the strain gauge readings taken at the root and at mid span. The effects of twist angle and number of blades are also discussed. The study does not include riveted construction.