Experimental investigation on the unsteady surface pressure fluctuation patterns over an airfoil

This article presents a comprehensive mapping of wall-pressure fluctuations over an airfoil under three different inflow conditions to shed light on some basic assumptions taken for granted the recent aeroacoustic and aerodynamics experimental studies in noise prediction models. Unsteady steady pressure measurements were performed heavily instrumented airfoil, which was exposed smooth inflow, grid-generated turbulent with tripping tape explore unsteady response broad range angles attack, [Formula: see text]. The results are presented terms non-dimensional coefficient, root mean square frequency-energy content pattern map at isolated frequencies entire spectra selected transducer locations. show that patterns tripped boundary layer turbulence ingestion cases dramatic difference compared conditions. differ across frequency, between both sides airfoil. suggest three-region case, two-region case. Moreover, indicate presence may provide flow necessary statistical characteristics rigs representing full-scale application; however, it misrepresent frequency-dependent nature layer.