Finite element analysis of the viscous flow in a vaned radial diffuser

Abstract A new finite element method was used to analyze an experimental model of a radial vaned diffuser. The new method includes a streamline upwind formulation for the advection terms in the governing equations. The streamline upwind significantly reduces numerical diffusion while maintaining the stability of the conventional upwind formulation. The new finite element method also incorporates an iterative equal-order, velocity-pressure solution method based on the well-known SIMPLER algorithm. The results of the analysis are compared to flow visualization studies of the experimental model. The flow separation point for the four blade diffuser was predicted to occur at 19, 6% of the blade length from the leading edge. The experimentally determined value was 23% of the blade length. For the eight blade diffuser model, separation was predicted to occur at 43% of the blade length from the leading edge, as compared to the experimentally observed value of 50% of the blade length. With this performance comparison, the proposed finite element method has been demonstrated to be reliable for predicting complex fluid flows.

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