| Fully developed incompressible turbulent flow in a conical diffuser having a total divergence of 8°and an area ratio of 4:1 has been simulated by a DHR k-εturbulence model and it's wall function·BFC(Boundary-Fitted Coordinates) method. The research has been done for pipe entry Reynolds numbers of 2.93 ×10~5 and 1.16 ×10~5. The calculated results of the distribution of the mean flow velocity u and turbulence energy k has been given out under the different calculated conditions respectively, such as radial fitted-body uniform grid system, near wall denseness model radial fitted-body non-uniform grid system, increasing twofold grid numbers and difference methods on the solid wall of the convection terms, and they were analyzed and compared with the test results respectively; At the same time, the distribution of the main parameters that flow u , k , turbulence dissipation ratio εand eddy viscosity coefficient νt are given out in conical diffuser. The effect degree of the calculated degree and operation efficiency has been studied under the different calculated conditions, and they have offered reference for engineering techniques actual application.
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