燃料泵柱塞油膜摩擦生热CFD仿真分析

Simulation Analysis of Fuel Pump Piston Oil Film Friction Heat Generation Based on CFD MethodCHEN

对水下燃气涡轮机动力系统燃料泵柱塞油膜摩擦生热问题,结合流体力学动网格和滑移网格方法,根据柱塞运动方程进行用户自定义函数编程,考虑油液的粘温特性建立燃料泵柱塞油膜仿真计算模型,并给出了柱塞油膜摩擦生热建模分析方法。根据所提出分析方法对柱塞油膜摩擦生热进行了仿真分析,研究了出口压力、壁面温度及转速等参数对油膜摩擦生热引起温度变化的影响规律。获得如下结论:入口压力为0.5 MPa时,出口压力的变化对油膜温度上升影响较小,且油膜顶部位置温度上升量最大,在转速为2250 r/min工况下温度上升量可达4 K左右;2)在300~373 K范围内,壁面温度每上升20 K,油膜顶部温度上升量降低约50%,且373 K时油膜顶部温度上升量仅为300 K时的9.2%;3)油膜温度上升量与转速近似呈线性关系。

Aiming at the friction heat generation of fuel pump piston oil films for underwater gas turbines,combined with thecomputational fluid dynamics dynamic grid and slip grid methods,user-defined function programming is performed accordingto the piston motion equation.Furthermore,a fuel-pump piston oil-film simulation calculation model is established consideringthe viscosity-temperature characteristics of the oil.A modeling analysis method for the frictional heat generation of the pistonoil film is presented.Using the proposed analysis method,the frictional heat generation of the piston oil film was simulatedand analyzed,and the influences of the outlet pressure,wall temperature,and rotational speed on the temperature changecaused by the oil film frictional heat generation were studied.The following conclusions are obtained.1)When the inletpressure was 0.5 MPa,the changes in the outlet pressure had little effect on the temperature rise of the oil film.Moreover,thetemperature rise at the top of the oil film was the largest,and the temperature rise could reach up to approximately 4 K at therate of 2250 r/min.2)In the range of 300 K to 373 K,the temperature increase at the top of the oil film decreased byapproximately 50%for every 20 K increase in wall temperature.Moreover,the temperature increase at the top of the oil film at373 K was only 9.2%of that at 300 K.3)The temperature increase of the oil film and the rotation speed have an approximatelylinear relationship.