The calculation of turbulent flow in wide-angle diffusers

The present investigation is concerned with the calculation of flow in conical, wide-angle diffusers where axisymmetric separation is common. The investigation has the objective to develop and test a numerical method for calculating the properties of turbulent flows in wide-angle diffusers with and without swirl. The method can also be applied to small-angle diffusers. The steady, two-dimensional elliptic equations, used to represent the turbulent recirculating flows with and without swirl in the diffuser, are expressed in orthogonal curvilinear coordinates and solved in finite-difference form with computer storage (23k words) and run times (approximately 300 s of CDC 6400) which are acceptable in engineering practice. A comparison of calculated and experimental results indicates that the general features of the flow field are correctly predicted.