Print Email Facebook Twitter Determination of mean pressure from PIV in compressible flows using the Reynolds-averaging approach Title Determination of mean pressure from PIV in compressible flows using the Reynolds-averaging approach Author van Gent, P.L. (TU Delft Aerodynamics) van Oudheusden, B.W. (TU Delft Aerodynamics) Schrijer, F.F.J. (TU Delft Aerodynamics) Date 2018-03-01 Abstract The feasibility of computing the flow pressure on the basis of PIV velocity data has been demonstrated abundantly for low-speed conditions. The added complications occurring for high-speed compressible flows have, however, so far proved to be largely inhibitive for the accurate experimental determination of instantaneous pressure. Obtaining mean pressure may remain a worthwhile and realistic goal to pursue. In a previous study, a Reynolds-averaging procedure was developed for this, under the moderate-Mach-number assumption that density fluctuations can be neglected. The present communication addresses the accuracy of this assumption, and the consistency of its implementation, by evaluating of the relevance of the different contributions resulting from the Reynolds-averaging. The methodology involves a theoretical order-of-magnitude analysis, complemented with a quantitative assessment based on a simulated and a real PIV experiment. The assessments show that it is sufficient to account for spatial variations in the mean velocity and the Reynolds-stresses and that temporal and spatial density variations (fluctuations and gradients) are of secondary importance and comparable order-of-magnitude. This result permits to simplify the calculation of mean pressure from PIV velocity data and to validate the approximation of neglecting temporal and spatial density variations without having access to reference pressure data. Subject PressurePIVReynolds-averaged Navier-Stokesbase flow To reference this document use: http://resolver.tudelft.nl/uuid:0be1d45d-ceb2-488f-a541-393459cfd609 DOI https://doi.org/10.1007/s00348-018-2487-2 ISSN 0723-4864 Source Experiments in Fluids: experimental methods and their applications to fluid flow, 59 (3) Bibliographical note green Part of collection Institutional Repository Document type journal article Rights © 2018 P.L. van Gent, B.W. van Oudheusden, F.F.J. Schrijer Files PDF 10.1007_s00348_018_2487_2.pdf 3.15 MB Close viewer /islandora/object/uuid:0be1d45d-ceb2-488f-a541-393459cfd609/datastream/OBJ/view