Effects of lobe geometry on the mixing flow in multilobe mixers

This study is concerned with a numerical investigation of the mixing flow i n multilobe mixers. Predictions are obtained using a finite-volume method w hich incorporates a second-order difference scheme. The irregular boundarie s are fitted by curvilinear nonorthogonal grids and the grid points are arr anged in the collocated manner. A method is described to generate suitable three-dimensional grids to cover both the lobe region and the mixing duct. Computations ave undertaken to examine the effects of lobe geometry on the mixing performance. Results indicated that the convex lobe contour can lead to stronger vortex flow and, thus, better mixing because of its large slop e. As for the geometry of the lobe trailing edge, a sinusoidal shape with w ide peak region gives rise to roell-organized vortices and the mixing perfo rmance is enhanced. Also revealed is the mechanism which, resulting in effi cient mixing in the mixer, is clearly identified.