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A numerical and experimental analysis is performed to study specific features of shock wave formation near a wedge with the leading edge having a bluntness radius that is small as compared to the wedge size and commensurable with the mean free path of molecules in the free stream. Numerical solutions are compared with the shock polar that describes the pressure and angle of flow deflection behind the shock in the inviscid formulation Based on numerical simulations with allowance for viscosity, the internal structure of the shock wave predicted by the two-dimensional computation is compared with that of the one-dimensional shock wave. Comparisons are performed at the stagnation line and further downstream. The results of these comparisons are explained with the use of total enthalpy fields. Comparisons of density distributions inside the shock wave for different bluntness radii are used to explain the Schlieren visualization patterns observed in experiments. It is shown that reduction of the bluntness radius of the leading edge of the wedge significantly alters the mechanism according to which the shock wave is formed in the flow above the wedge surface at a distance of more than 100 mean free paths of air molecules, resulting in downstream shifting of the point where the shock wave with parameters corresponding to the Rankine-Hugoniot relations is formed. [ABSTRACT FROM AUTHOR]

The need of circulatory support systems in the treatment of chronic heart failure is increasing constantly, as 20% of patients in the waiting list die every year. Despite the great need for mechanical heart support systems, using of available systems is limited by the expensiveness. In addition, there is no one system that is 100% responsible to all medical and technical requirements, and would be completely safe for patient. Therefore, further research in the field of circu-latory support systems, considering health and technical requirements is relevant. One of the new directions in the study are disc pumps of viscous friction for liquid transporting, based on the Tesla pump principle. The operation principle of pumps based on the phenomenon of the boundary layer which is formed on the disk rotating in a fluid. There are experimental studies results of models with different variants of the rotor suspension, the various forms and the number of disks, forms the pump housing. However, none of the above samples was not brought to clinical trials. Furthermore, despite the promise of this model is still used today in some circulatory support systems are no similar type pump. Published data provide a basis for further development and testing of the pump model and allow to hope for leveling a number of significant shortcomings of modern left ventricular bypass systems. [ABSTRACT FROM AUTHOR]