NUMERICAL PREDICTION OF TURBULENT FLOW IN A CONICAL DIFFUSER USING k-ε MODEL

【摘要】 <正> Fully developed incompressible turbulent flow in a conical diffuser having a total divergence an-gle of 8° and an area ratio of 4:1 has been simulated by a k-ε turbulence model with high Reynolds num-ber and adverse pressure gradient.The research has been done for pipe entry Reynolds numbers of 1.16×10~5and 2.93×10~5.The mean flow velocity and turbulence energy are predicted successfully and the advantage ofBoundary Fit Coordinates approach is discussed.Furthermore,the k-ε turbulence model is applied to a flowin a conical diffuser having a total divergence angle of 30° with a perforated screen.A simplifiedmathematical model,where only the pressure drop is considered,has been used for describing the effect of theperforated screen.The optimum combination of the resistance coefficient and the location of the perforatedscreen is predicted for high diffuser efficiency or the uniform velocity distribution.更多还原

【Abstract】 Fully developed incompressible turbulent flow in a conical diffuser having a total divergence an- gle of 8° and an area ratio of 4:1 has been simulated by a k-ε turbulence model with high Reynolds num- ber and adverse pressure gradient.The research has been done for pipe entry Reynolds numbers of 1.16×10~5 and 2.93×10~5.The mean flow velocity and turbulence energy are predicted successfully and the advantage of Boundary Fit Coordinates approach is discussed.Furthermore,the k-ε turbulence model is applied to a flow in a conical diffuser having a total divergence angle of 30° with a perforated screen.A simplified mathematical model,where only the pressure drop is considered,has been used for describing the effect of the perforated screen.The optimum combination of the resistance coefficient and the location of the perforated screen is predicted for high diffuser efficiency or the uniform velocity distribution.更多还原