DOI: 10.1615/TSFP2
DNS STUDY ON THE MEASUREMENT OF TURBULENT WALL SHEAR STRESS USING SURFACE-MOUNTED HOT-FILM SENSOR
要約
The influence of heat conduction on the response of a surface-mounted hot-film sensor has been numerically investigated with special attention paid to turbulent wall shear stress measurements. Energy transport equation is solved for both fluid and solid parts, where the thermal conductivity of the solid part is varied to realize various materials common in constructing the wind tunnel wall, and a sensor operating under the constant temperature is emulated. The results indicate that the better signal is obtained by the sensor when it is attached on the wall whose thermal conductivity is higher than that of the substrate. It is the heat flow from the hot-film transferred in the substrate by conduction, that contaminates the response of the sensor, because the enlargement of the virtual size of the sensor due to conduction results in low streamwise resolution.