Research on the behavior of obstructed round buoyant vertical jets in static ambient, 1, verification of mathematical model and numerical method

The RNG turbulence model considering the buoyancy effect is used to establish a mathematical model of obstructed round buoyant vertical jets in static ambient.The hybrid finite analytic method with stagged grid is used to solve this model With the concept of concentration correction factor,the effect of the disc to improve the near field dilution of buoyant jet is confirmed.Meanwhile,the H/D,H is vertical distance of disc from jet exit section and D is disc diameter,primarily affects the concentration distribution behind the disc.It is found that the range of Froude number,in which normal round flowing occur,decreases quickly while H/D <1.When the plate is near the port,jet can be easily reverberated by the plate,and when the plate is far from the port,the round flow after the plate will bifurcate out of the range of Froude number.The two steps to control flow pattern and improve dilution on the axial near the plate are proposed also.