Abstract
A numerical analysis is presented in the case where a cold plane water jet is discharged near the free surface of a co-current uniform water flow with linear temperature stratification in a long channel. Reichardt's virtual kinematic viscosity for a turbulent two-dimensional free jet, which has been modified with regard to the size of the discharge port, is used for the governing equation of the present analysis. Also, the virtual Prandtl number is assumed to be 1/2. Examples for the variation of distributions of the stream function and the temperature are described for a 200 m deep the channel, 10 m in width at the discharge port, 1 m/s in the velocity at the discharge port, and 0.05 m/s in the velocity of the main flow. The temperature of the discharged water equals the initial temperature at a depth of 4/5 of the main flow.
Initially, the jet flows downwards. However, the distance from the exhaust port to the front of the jet is small. A large eddy that formed behind the jet stream gradually expands, flows downstream of the main flow, and disappears. Finally, a large single circulation flow in the channel is formed. These phenomena are quite different from those hitherto reported about cold water jets discharged into a quiescent water pool with uniform temperature.
