Thermal structure of turbulent stagnating opposed jets with different temperature

Fluctuating temperature has been measured using a laser Rayleigh scattering technique along a centerline of turbulent stagnating opposed jets (cold jet velocity: 2 m/s) with different temperatures up to about 400 °C. The temperature signals show that the temperature fluctuation is characterized by spike type fluctuations with a sharp increase or decrease in temperature between hot and cold jets. This indicates that the temperature fluctuation is mainly attributed to the large-scale fluctuations of the boundary between the hot and cold jets. Profiles of mean temperature and rms value of fluctuating temperature can be normalized using a similarity parameter based on the bulk strain rate, characteristic intensity and scale of the turbulence when the temperature difference is less than 200 °C.