A flex-fan has flexible blades which undergo large deformation under centrifugal forces to give the desired air-flow and power-consumption characteristics with speed. The finite element technique has been used to obtain the deflected shape of the blade of such a fan used for automobile radiator cooling. The natural frequencies of vibration are also evaluated at different speeds, up to 5,000 rpm. A partially conforming deflection function has been used in the analysis. The blade has been treated as a thin shell, idealized as an assembly of thin flat triangular elements. / Thesis / Master of Engineering (ME)