Numerical Simulation And Prediction Study Of Inner Turbulent Flow Field In Diffuser Tube System

Fully developed incompressible viscous turbulent flow with adverse pressure gradient in a conical diffuser tube system having a divergence of 4°and an area ratio of 4 has been simulated and diagnosed by a DLR k-εturbulent model and it's BFC(Boundary-Fitted Coordinate Transformation) method.The research has been done for pipe entry Reynolds number of 1.16×10⁵ and 2.93×10⁵.Based on the near wall denseness model radial fittedbody nonuniform grid system,The calculated results of 36 cases have been given under the different calculated conditions,such as different model function combinations,different grid dispositions,predigest theεfunction with pressure function and different I with differentâ–³t.They were compared with the experimental results respectively.The parameter distributions of the area have been given respectively,including the distributions of the mean flow velocity(?)(?),mean pressure(?),turbulent energy k,turbulent dissipationε, eddy kinematic viscosity v_t and the coefficient of wall pressure C_pw.The results of numerical simulation have been diagnosed in order to obtain the more accurately numerical prediction results,which haven't been gotten by using material experiment and model experiment,the results have offered relatively credible reference for turbulent theoretical research and engineering technical actual application.At last,the researcher has been summarized this article and the work in the future have been put forward.