Broadband noise measurement in the transonic test section of the VTI T-38 wind tunnel

Broadband noise level measurements in the T-38 wind tunnel trisonic test section having slanted holes treated for edgetone reduction have been performed. Results show that the splitter-plates have shifted the test section resonant peak condition toward lower Mach numbers, providing low broadband noise level at transonic speeds. No presence of high resonant frequencies was experienced. All resonant frequencies are located in the low frequency domain (below 100 Hz) which is not usually observed in other transonic facilities. No Reynolds number or wall porosity effect on results were found.