某航空齿轮润滑喷嘴结构对喷嘴射流特性的影响研究

为了研究喷嘴结构对喷嘴射流扩散角和射流流量的影响，采用基于FLUENT的大涡数值模拟方法对喷嘴三维射流流场进行了二相流仿真和单相流仿真，分别通过高速可视化和喷射滑油称重的方法测量了喷嘴射流扩散角和射流流量，并用测量结果对二相流仿真和单相流仿真进行了合理性验证.当喷嘴长径比大于2且喷孔轴线与喷孔上游管道轴线的夹角在0°~90°之间时沿喷孔轴线距喷孔出口100mm范围内射流扩散角近似为零，且增加喷孔直径、喷孔轴线与喷孔上游管道轴线的夹角或者减小喷孔轴向长度均会引起射流流量的增加.结果表明:当喷嘴长径比大于2且喷孔轴线与喷孔上游管道轴线的夹角在0°~90°的范围内变化时对射流扩散角的影响很小；喷孔直径、喷孔轴向长度和喷孔轴线与上游管道轴线的夹角通过影响局部损失和沿程损失，从而影响喷嘴射流流量. 

Studies on the effects of structural parameters on jetcharacteristics of nozzlesin in lubricating aviation gears

In order to study the effects of the supply pressure and temperature of oil on the diffusion angle and volume flux of jet oil sprayed by nozzles of gear cases, both the two phase and single phase flow models of the jet flow field of three dimensional nozzles were simulated by employing the Large Eddy Simulation based on the FLUENT. The rationality of the simulation results of the two phase and single phase flow models of jet flow field of three dimensional nozzles was demonstrated by the diffusion angle and volume flux of jet oil measured by the method of high speed visualization and weighting jet oil, respectively. The diffusion angle of jet was approximately zero within the scope of 100 millimeters along the axis apart from the exit of nozzle when the ratio of length to diameter was greater than 2 and the angle between the axis of nozzle orifice and the axis of upstream flow channel changed in the range of 0 to 90 degree. The volume flux of jet oil increased as the orifice diameter, the angle between orifice axis and upstream axis increased and as the orifice axial length decreased. The result indicate that the diffusion angle of jet is not affected in actual working conditions when the ratio of length to diameter is greater than 2 and the angle between the axis of nozzle orifice and the axis of upstream flow channel changes in the range of 0 to 90 degree. Both the local loss and the linear loss are influenced by the change of the orifice diameter, the orifice axial length and the angle between orifice axis and upstream axis, finally leading to variation of volume flux of jet.