Numerical Investigation of Pressure Measurement by Pitot Tubes in Micro-scale Taylor Couette Flow with Hyper Rotational Speed and its Correction

Abstract As the most classic technique in fluid mechanics, the pitot tube has been employed for hundreds of years. Its feasibility is based on the premise that the measured fluid is ideal, irrotational, and incompressible, and the presence of pitot tube does not interfere with the measured flow field. However, the development of rotating machinery, especially Dynamic Gas Bearing, has brought about strong dissipation, large gradients, and scale effects in the shear flow between the rotor and stator, which urgently require pressure correction as conventional pitot tube has been utilized. The physical mechanism of the influence of the existence of pitot tubes on micro-scale shear flow has been revealed. The cavity formed by the pitot tubes interferes with the shear flow in the transition static gap, causing instability in the shear flow. Compared to the absence of a pitot tube, the pitot tube has brought 3.5% -10% of underprediction of mean pressure. the effects of rotational speed, clearance has been performed in microscale hyper-rotational speed shearing flow. A pressure correction method using the pitot tube pressure was presented for strong dissipation, large gradients, and scale effects, verifying its effectiveness in microscale hyper-rotational speed Taylor Coulter flow.