航空燃油离心泵内流特性分析

针对航空发动机燃油离心泵内流特性研究,采用雷诺平均方法和滑移网格技术,在多工况下进行数值模拟,得到了内部流场细节和压力流量曲线。结果表明:由于流体绕过叶根时加速,可能出现局部低压区并导致气蚀;随着流量的增大,叶轮中相对速度增大,根据速度合成法可知,叶轮边缘出流速度随之减小,最终导致泵内静压降低;随着转速的提高,泵内速度和静压增大,且叶根附近出现局部高流速低压区并逐渐扩张,此区域也是局部低压区。根据压力流量曲线可知,随着流量的增大,泵输出的压力降低;随转速的提高,泵输出的压力升高;在低转速条件下,大流量运行无法实现。

Analysis on Internal Flow Characteristics of Aviation Fuel Centrifugal Pump

In order to research the internal flow characteristics inside the aviation fuel centrifugal pumps, the Reynolds average method and the sliding grid technology are adopted. The numerical simulations are performed under various working conditions, and the internal flow field details and the pressure-flow curves are obtained. The results show that due to the acceleration of the fluid bypassing the blade root, a local low-pressure area may appear and cause the cavitation. With the increase of the flow rate, the relative velocity in the impeller increases, and the outflow velocity from the impeller decreases according to the velocity composition law. This finally causes the decrease of the static pressure in the volute. With the increase of the rotational speed, the velocity and the static pressure in the pump increase. In addition, a local high-velocity and low-pressure zone appears near the blade root and gradually expands. According to the pressure-flow rate curve, with the increase of the flow rate, the output pressure of the pump decreases. With the increase of the rotational speed, the output pressure of the pump decreases. Under a low rotational speed, the pump cannot achieve a large flow rate.