环形腔室径向宽度对加力燃油泵内流及性能影响

对某加力燃油泵内部非定常流动开展了系统的数值模拟,研究了不同环形腔室径向宽度条件下泵的外特性和内流特征.计算结果表明,缩小径向宽度可有效提高泵在不同流量下的扬程,且小流量工况增幅显著高于大流量,明显改善了小流量工作的不稳定性.对于大流量工况,环形腔室截面变小导致腔室内循环流量降低、沿程损失明显减小,是泵出口扬程提高的主要因素;而对于小流量工况,环形腔室截面变小使得扩散管主流贴近环形腔室,显著降低了叶轮流道扬程损失,有效提升了泵出口扬程.

Effect of annular chamber radial width on the performance and inner flow characteristics of an after-burning oil pump

A series of unsteady numerical simulations was conducted for an after-burning oil pump and the effect of annular chamber radial width on the pump performance and inner flow characteristics was investigated.Decrease of the radial width can increase the pump head under different flow-rates and the head increase under small flow-rate condition is larger than that under large flow-rate condition,which improves operation stability under the small flow-rate.Under the large flow-rate condition,annular chamber head loss is reduced by the decrease of circulation flow-rate in annular chamber resulted from the decrease of the annular chamber and following circumferential section area.Accordingly pump head is raised.While,under the small flow-rate condition,decreasing annular chamber radial width makes the incoming flow of the diffuser approach to annular chamber,which reduces the impeller passage head loss.As a result,pump head is enhanced significantly.