采用κ-ε湍流模型和非等间距加密网格,对射流泵流场进行了数值模拟和分析,并对相应的流场进行了实验研究。结果表明,流场轴向速度剖面在扩散管段具有较好的自相似性。而在喉管段则不然:这种速度剖面变化的转折点与喉管的长度有关;流场的湍动能分别在喷嘴出口与扩散管入口处产生峰值,并且前者远大于后者。可见射流泵流场中,湍流主要发生在喉管入口处,湍动能的不平衡将导致额外的能量损失。本研究结果对工程应用有指导意义。
The κ-ε model and unequal interval computational meshes were used to analyze and numerically simulate the turbulent flow in the jet pump, and corresponding experiments were performed. The results show that the axial velocity profiles possess well self-similarity in the diverging portion, however, it does not in the throat. The transition point from non-similarity to self-similarity is related to the length of the throat. The maximum turbulent energy of the flow occurs in the exit of the jet and the entrance of the diverging portion, and the former is much larger than that of the latter. Therefore it can be seen that the turbulence is produced mainly in the entrance of the throat. The unbalance of turbulent energy will bring about the additional energy loss. The conclusions of the study are helpful to the engineering practice.