Analysis and Numerical Solution of Three-Dimensional Viscous Internal Flow Problems.

Abstract

Abstract : This research is motivated by the need for accurate prediction of three-dimensional viscous flow in a turbine or compressor passage. As a major step towards the investigation of these problems, the three-dimensional entrance flow through ducts of various regular cross-sections, with longitudinal and transverse curvature effects, have been studied. The mathematical model has been formulated using time-averaged three-dimensional parabolized Navier-Stokes equations. The analysis has been developed using an existing two-equation turbulence model and is checked by obtaining satisfactory comparison of the present results for straight and curved circular pipes. The effects of the problem parameters on the flow fields are accurately evaluated and the limitations of the turbulence model have been briefly stated. Four related areas were identified and studied separately. These consist of the law of the wall, coordinate transformations and efficiency and accuracy of the numerical algorithm. The last three of these areas have been studied with some success already, and the additional analysis developed will be implemented in the basic turbulent-flow program to make the latter a truly predictive tool.