AbstractA brief overview of classes of turbulent swirling flow in conical diffusers is given, together with a description of appropriate numerical schemes for each class. Numerical results obtained for the class of moderate swirl in a 20° diffuser and for the class of no swirl in an 8° diffuser are compared with experimental results. The results are obtained using a multi‐sweep scheme solving the full steady state time‐averaged Navier–Stokes equations. Turbulence quantities are approximated using two types of algebraic Reynolds stress model and two types ofk–ϵ model. One of the algebraic Reynolds stress models includes extra production terms associated with the Christoffel symbols in cylindrical co‐ordinates, and one of thek–ϵ models includes a swirl‐related modification to the ϵ equation. It is demonstrated that the standardk–ϵmodel gives poor prediction of the mean flow, and it is necessary to at least use the modified form or one of the two algebraic R
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