BTA深孔钻杆系统切削液液膜压力的分布特性

摘要

研究深孔钻杆系统中非线性流体力的分布特性.采用有限差分法求解非线性流体力控制方程,分析偏心率、长径比、涡动速度和振动速度对非线性流体力分布的影响.研究结果表明:非线性流体力随着偏心率的增大而增大,而随着长径比的增大变化不明显,尤其是对于大的长径比;随着正向涡动速度的增大,收敛区的非线性体力而增大,发散区的非线性流体力减小,而反向涡动速度对非线性体力的影响规律恰好相反;非线性流体力随着正向振动速度的增大而增大,随反向振动速度的增大而减小,此外,在最小间隙处的压力因振动速度的改变而出现极值,从而导致收敛区和发散区压力分布的反对称特性消失.%The distribution characteristics of nonlinear hydrodynamic force in deep hole drilling system were studied.The governing equation of the nonlinear hydrodynamic force was solved by using the finite difference method.The effects of eccentricity,the ratio of length to diameter,whirling velocity and vibration velocity on the distribution of nonlinear hydrodynamic force were discussed.The results show that the nonlinear hydrodynamic force is increased with the increasing of eccentricity,but its change is not obvious with the increasing of the ratio of length to diameter,especially for large ratio of length to diameter.With the increasing of the positive whirling velocity,the nonlinear force in the convergence zone is increased,while the nonlinear force in the divergence zone is decreased.The influence law of the reverse whirling velocity on the nonlinear force is just opposite to that of the positive whirling velocity.The nonlinear fluid force is increased with the increasing of the positive vibration velocity and decreased with the increasing of the positive vibration velocity.In addition,the extreme value of the pressure at the minimum clearance occurs due to the change of the vibration velocity,which leads to disappearance of anti-symmetry characteristics of the pressure distribution in the convergence and divergence zone.