湍浮力射流形成区内特性的预报

应用作者所提出的数学模型和计算方法,对浮力射流形成区内的特性进行了预报。得出了形成区内中线流速、温度和湍动能的沿程变化,以及射流核的长度和掺入速度。也得出了流速、温度和湍动能在断面上的分布。并分析和讨论了出口条件及环境分层对这些特性的影响。

Prediction of Characteristics for ZFE of Buoyant Jets

The mathematical model and calculational method presented in [2] are used to predict the characteristics of the zone of flow establishment of buoyant jet issuing vertically into static uniform, linear stratified and partial stratified environments. The developments of the centerline velocity, temperature and turbulent kinetic energy in ZFE are calculated. The length of buoyant jet core, the entrainment velocity, the lateral velocity, temperature and turbulent kinetic energy profiles are given. The exit conditions and stratification of environment are found to have strong influence on the behavior of buoyant jet in the zone of flow establishment.It is found that the centerline velocity in the zone of flow establishment is accelerated due to the buoyancy force and reaches to its maximum value at the end of the buoyant jet core. The length of buoyant jet core increases with the increase of the exit Froude number. As the Froude number is larger than 100 the core length will be constant. The core length decreases with the increase of the strength of stratification of environment.The centerline turbulent kinetic energy decreases firstly and increases afterwards in the zone establishment. The point where the turbulent kinetic energy reaches its minimum value moves downstream from exit of jets with the increase of exit Froude number or environment stratification.