Side channel pumps provide high pressure at relatively low flow rates. This comes along with a quite low specific speed and thus with the known disadvantage of a quite poor maximum efficiency. This paper describes the detailed analysis and optimisation of a typical 1-stage side channel pump with an additional radial suction impeller by means of computational fluid dynamics (CFD) simulations. In a first step, the model was successively generated and it was obvious that it has to contain all details including suction impeller and main stage (both 360° models) as well as the pressure housing and all narrow gaps to provide useful simulation results. Numerical simulations were carried out in a stationary and transient way with scale resolving turbulence models to analyse the components in detail. Finally the CFD-simulations were validated with model tests. For the optimisation process it was necessary to generate a reduced numerical model to analyse the effects of more than 300 geometry variations. The findings were then combined to establish the desired objectives. Finally the best combinations were validated again with the full numerical model. Those simulations predict a relative efficiency increase at best efficiency point (BEP) and part load >30% with respect to all given limitations like identical head curve, suction behavior, and dimensions.

The demand for low-noise auxiliary drives has been increasing in the automotive industry, as the entire noise level within the vehicle interior has been continuously decreasing over the recent years. In contrast to "larger" drives, the fractional horsepower (FHP) auxiliary drives used here are not subject to any standards. They are customized solutions and hardly anything is reported on their noise and vibration characteristics. Furthermore, their design is very much cost-driven, and noise performance is mostly treated in a retrofit approach within the final system. This article determines the noise and vibration characteristics of FHP auxiliary fan drive systems as typical for use within LED headlights for thermal management. It provides tools for further systematic analysis and eventual mitigation of potentially disturbing noise of such drives already at the development stage.

This paper describes the detailed analysis of a multistage canned motor pump with an additional radial suction impeller by means of CFD simulations to determine the main losses and to establish optimization potential of the hydraulic parts. In addition to the main flow channels of the impeller, the degree of detail of the analysis also includes the front and rear impeller side spaces, relief holes, gaps, return sections and all hydraulically wetted surfaces of the canned motor. The model presented was successively generated and already at a very early stage it was obvious that the model has to contain all details mentioned in order to provide valuable simulation results. For the impeller, the gaps and the pressure relief holes primarily structured meshes were used with a final model of the existing pump consisting of more than 35 million nodes. The behavior of the main components was analyzed in detail and additionally the CFD simulations — stationary and transient — with scale resolving turbulence models were validated by means of model tests. Furthermore, a comprehensive loss analysis of the existing pump was performed to verify the optimization potential. The subsequent optimization was realized semi-automated. A tight corset of requirements, e.g. identical head curve, suction behavior and dimensions, has been defined to guarantee retrofit capability of the pump analyzed in order to fully satisfy the demand for a constant delivery head curve and at the same time to provide for a relative increase of the optimum efficiency by 25% and in a wide range of applications by at least 20%. The optimized model was manufactured based on rapid prototyping and tested in the laboratory. The results show a satisfying correlation between the numerically predicted and the measured results on the test rig and prove the high quality of the numerical simulations run.

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