涡轮钻具花键轴流道水力损失分析及尺寸优选

摘要

为确定涡轮钻具花键轴上过流槽安装位置、形状、倾斜角度、长度和宽度等的最佳组合,利用CFD软件模拟花键轴流道的流场,根据模拟结果用伯努利方程计算水力损失和局部阻力系数,并对过流槽倾斜角度和断面面积与局部阻力系数之间的关系用Polynomial五次曲线模型和Logistic曲线模型进行非线性回归分析。分析结果认为,随着倾斜角度的不断增大,花键轴内流体的能量损失及局部阻力系数先减小后增大;在不同流量下,随着横断面面积的增大,花键轴进出口压降随之减小,但当横断面面积增大到一定程度后,其对能量损失和局部阻力系数的影响不大。%To determine the optimum dimensional combination of installation position,form,tilt angle,length and width of flow duct on turbodrill spline shaft,the computational fluid mechanics software was applied to simulate the flow field of spline shaft flow channel.According to the simulation result the Bernoulli equation was used to calculate hydraulic loss and local resistance coefficient.A nonlinear regression analysis was conducted of the relationship between tilt angle of flow duct,flow cross section area and local resistance coefficient through Polynomial quintic curve model and Logistic curve model.The analysis shows that with the increase of tilt angle,the energy loss and local resistance coefficient of fluid in spline shaft decrease first and then increase.Under different flow rates,with the increase of cross section area,the pressure drop at the inlet and outlet of spline shaft decreases.However,when the cross section area increases to a certain extent,its effect on energy loss and local resistance coefficient is not remarkable.