Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 19, 2024 - November 20, 2024
To investigate the effects of wavelength of rough surface undulation on turbulent heat transfer over rough surfaces, we measured turbulent heat transfer for turbulent channel flow over three-dimensional sinusoidal rough walls with different wavelength. We used temperature-sensitive paint (TSP) to measure the temperature at rough surfaces. The rough surfaces were heated with constant heat flux, and the roughness Reynolds numbers based on the equivalent sand grain roughness were varied up to 1000. The results showed that the increase in heat transfer rate due to roughness is pronounced for rough surfaces with shorter wavelength. It was also confirmed that the temperature roughness function, which represents the downward shift in the logarithmic mean temperature profiles strongly depends on the wavelength of rough surfaces.
