Abstract:To investigate the effect of bend inlet on the dynamic characteristics of mixedflow impellers, adopting numerical simulation method, the performance and characteristics of radial force of mixedflow impellers installed at the point of three pipediameter long away from the bend and on the straight pipe respectively were simulated and analyzed. After steady analysis of the flow field and comparing the axial speed distributions at the impeller inlet, the results show that axial velocity distribution at the inlet has obvious velocity differences in bend plane with bend inlet, but the performances of pumps with straightpipe inlet and bend are basically identical, corresponding with test results. the unsteady simulations under designed flowrate show that the impeller with straight pipe inlet almost has no steady radial force, while the impeller with bend inlet has an obvious increase of steady radial force, especially the unsteady radial force at blade passfrequency, but the unsteady radial force caused by activity and inertia interference remains basically the same. These analyses can be referential for fixedflow and structure design with bend inlet.
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