Wavenumber spectrum determination for transsonic wind tunnel measurements using FISTA

Abstract

This paper deals with computational methods to determine the wavenumber spectrum of pressure fluctuation data measured by a phased sensor array underneath a transsonic boundary layer. The data are measured underneath a turbulent boundary layer of a flat plate in the transsonic wind tunnel Braunschweig with closed test section . The data were were previously published in 2012 using beamforming and a a so called embedded DAMAS2 deconvolution algorithm to obtain the wavenumber spectrum [1]. The aim of this paper is to re-post-processing these data with the newly introduced framework to find a well-defined unique solution with parametric L1 and L2 regularization. The measurements were conducted in the Transonic-Wind-Tunnel Gottingen (TWG) a continously working wind tunnel with a cross section of 1 m x 1 m. A rigid flat plate with a length of about 2.75 m was mounted symmetrically in the closed test section. In the downstream part of the plate a sensor array with 48 piezo-resistive transduces is integrated using a threaded mounting.