Structure of Grid Turbulence through a Heated Screen

Measurements of mean values and turbulent intensities of velocity and temperature fluctuations of grid turbulence have been done in a developing region just after an electrically heated screen. The air velocity is set as 1 m/s. The electric current to the screen is adjusted to be the downstream temperature (T_a) 32°C, 100°C or 150°C. A hot wire anemometry with compensation of temperature variation is used to measure velocity with temperature variation. In a developing region, both velocity and temperature distributions become non-uniform at just downstream of the heated screen. The distributions recover gradually to the uniform condition in a downstream region. A turbulent energy dissipates with the distance from the heated screen. The dissipation rate is decreased with increasing air temperature.