Experimental investigation of the flow through axisymmetric expansions

This study examines the flow field in three axisymmetrtic expansions having diffuser halft-angles of 14, 18, and 90 deg, respectively. Velocity measurements were performed at a Reynolds number of Re=1,56×10 4 using a single component LDA operated in forward scatter. The test facility was refractive index matched, allowing measurement of the velocities U, V, W, u 2 , v 2 , w 2 , uv and uw upstream of, and throughout the entire recirculation region. The results indicate that the diffuser geometry influences the separated shear layer appreciably over the entire length of the diffuser section