航空发动机内啮合摆线齿轮泵高空特性数值研究

Numerical Investigation on Altitude Performance for Aeroengine Gerotor Pump

关键词:  摆线齿轮泵  高空特性  容积效率  流量脉动

Key words:  Gerotor pump  Altitude performance  Volumetric efficiency  Flow pulsation

摘要:

高空性是评价航空发动机齿轮泵性能的关键参数之一，为了获得摆线泵的高度特性曲线，并分析其影响因素，采用三维非定常数值模拟的方法，应用动网格技术对单级内啮合摆线齿轮泵的高空特性进行定量分析。结果表明:随着飞行高度增加，摆线泵内的空化现象加剧，供油流量减少；当飞行高度在8km以上时，容积效率随高度上升而急剧下降，且在相同的出口条件下，低转速摆线泵的容积效率明显高于高转速工况；当飞行高度在8km时，增大摆线泵出口压力，出口流量脉动幅度由时均流量的16%增至20%，且出口流量的脉动频率随摆线泵的转速加快而变大。所以，摆线泵在高空工作时，降低转速即可以满足供油需求，同时减少系统负担。

Abstract:

The altitude performance is a key parameter for the aeroengine pump. Using three-dimensional unsteady numerical method，a single-stage gerotor pump was investigated with dynamic mesh to get the altitude performance curve，and the effects of different factors were analyzed. Results show that the cavitation in the gerotor pump intensifies as flight height increases，which leads to a decline in volume flow rate. When the altitude is above 8km，volumetric efficiency decreases rapidly as the altitude increases，while with the same outlet pressure，volumetric efficiency is higher with lower rotation speed compared with higher rotation speed. When the altitude is 8km，increasing outlet pressure leads to an increase of outlet flow pulsation amplitude from 16% to 20% of the time-averaged flow，and pulsation frequency increases with the rotation speed. Therefore，a lower rotation speed will meet the fuel feeding requirements in high altitude to reduce the system load.