<div class="htmlview paragraph">For the combination of radiator and fan working under high flow resistance of radiator system, “the Axial Flow Fan with Diagonal Flow Hub” has been developed.</div> <div class="htmlview paragraph">A study of the useful ranges of the cone angle of diagonal hub and depth of fan, two dimensionless shape parameters are presented and confirmed through experiments.</div> <div class="htmlview paragraph">With One Dimensional Theory and calculation of meridional streamlines by the Stream Curvature Method, diagonal flow effect, especially near the hub, has been discussed.</div> <div class="htmlview paragraph">From the performance tests and flow visualization method by tufts concerning typical combinations of the values of fan depth and cone angle, the better performance and favorable stream conditions are clarified.</div> <div class="htmlview paragraph">On the standard shape of diagonal flow hub putting the results of performance tests into the curves of two shape parameters, the optimum shape regions are presented.</div>