Abstract
Validation of flow topologies within rotary Ventricular Assist Devices (VADs) remains challenging due to small geometric dimensions of these pumps. Blood damage induced by VADs is suspected to be correlated to local flow patterns and therefore numerical simulation techniques established as a powerful tool for investigating local flow phenomena. Consequently, deep understanding of these flow fields contributes significantly to the design of blood-preserving Ventricular Assist Devices and increase life span of affected patients.
Different methods for verification of numerical simulations are available, but validations of applied turbulence models have so far been lacking. To close this knowledge gap, it is essential to examine flow fields inside a rotary blood pump by optical investigations. To realize optical accessibility for investigation of flow fields, and to validate turbulence models, it is necessary to abandon drive and bearing/suspension originally used in appropriate VAD designs. To draw reliable conclusions about hydraulic and mechanical characteristics, precise and reproducible investigations with low measurement uncertainty are mandatory. Only very accurate experimental results can be used to validate numerical simulations due to geometrical dimensions, constraints on manufacturing techniques, sensor accuracies, and materials.
In this paper a methodology is presented how to design the bearing/suspension of the impeller to fulfill mandatory requirements needed for validation of flow topologies. Furthermore, Gaussian Error Propagation is used to quantify achieved precision and reproducibility.
