Blade sections in streamwise oscillations into reverse flow

A low-Reynolds number rectilinear analog of the retreating-blade problem is considered by computationally and experimentally studying a NACA0012 blade in spanwise oscilla-tion in a free stream. Three-dimensional hybrid RANS-LES simulations with spanwise periodic boundary conditions and experimental flow visualization support the description of experimental direct force measurements for a wide range reduced frequencies and advance ratios, including fully reversed flow conditions. A fixed incidence of 6 degrees is taken as a nominally attached-flow case, and agrees reasonably well with Isaacs' theory. A fixed incidence of 20 degrees is taken as a fully-separated case, and departs markedly from invis-cid theory, and even more so from quasi-steady approximation. Experimental-computational comparison shows a computational overprediction of lift relative to experimental results, at moderate advance ratios. Agreement in fully reversed flow is, however, quite good.

Published in:
Annual Forum Proceedings - AHS International, 2583-2595
Presented at:
AHS International Forum, Virginia Beach, Virginia, USA, May 5-7, 2015

 Record created 2016-04-28, last modified 2018-09-13

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