Calculation of turbulent diffusion jets under effects of gravity and moving surrounding air

Abstract

The basis theory for the turbulent diffusion of jet and flame has been presented previously [1, 21. But that one applies only in quiet surrounding air with the effects of buoyancy neglected. In the present paper the theory is developed further by establishing an integral model for a jet in more general conditions with variable inclined angles, under effects of gravity and surrounding air velocity in any direction compared to the jet axis. The system of equations is closed by turbulence k-E model and is solved by 4 th order Runge- Kutta method. In the first stage, the model is applied to predict the velocity field, the concentration field and width development of a 0.3 m diameter jet.