The Computation of Secondary Flow in a 90° Rectangular Cross-Section Bend

An explicit time-marching scheme for incompressible inviscid three-dimensional flow is presented. The procedure uses an alternative method to the pseudo compressibility technique and uses the energy equation in place of the continuity equation. Calculations are performed for predicting the strong secondary flows produced when a shear flow enters a 90° bend with a rectangular cross-section. Good agreement is achieved with experimental results and rotation of the Bernoulli surfaces through almost 180° is obtained. Discrepancies in the predictions are largely due to the absence of the viscous terms in the computational model equations.