Numerical Prediction Of Inner Turbulent Flow With Adverse Pressure Gradient By Using DLR κ-ε Model

Fully developed incompressible turbulent fl.ow in a conical diffuser having a total divergence of 8° and an area ratio of 4:1 has been simulated by a DLR turbulent model and it's BFC (Boundary -Fitted Coordinates) method. Based on the near wall denseness model radial fitted-body uniform grid system ,the research has been done for pipe entry Reynolds numbers from 1.16 × 10~5 to 5 × 10~5. The mesh figure of physical plane is plotted. The calculated results of the distribution of the mean flow velocity and turbulent energy have been given out under the different calculated conditions, such as model functions, different grid rangement(including grid numbers and grid intervals) and reynolds numbers. The computational results are analysed and compared with the test results respectively. At the same time ,the distrubution of the main parameters that flow u|-, p|-, k, turbulence dissipation e and eddy viscosity coefficient v_t are given out in conical diffuser. It gets the effects of calculated results under the different calculated conditions,and they have offered reference for engineering technique's actual application.