恒定流速下三角型沟槽隔水管减阻性能的仿真分析

目的 为了提高隔水管的使用寿命和保障深水钻井的安全性,在只考虑同一流速下的海流力、不同沟槽的布置对隔水管受力影响的工况下,利用织构减阻的原理,将三角型沟槽织构引入隔水管表面来起到降低隔水管绕流阻力的作用.方法 采用大涡数值模拟,建立三角沟槽织构隔水管力学模型,在恒定流速下开展三角型沟槽深度和宽度几何参数对隔水管升阻力系...

Simulation Analysis of the Drag Reduction Performance of Triangular Groove Riser under Constant Flow Velocity

In order to improve the service life of the riser and ensure the safety of deep-water drilling, under the condition that only the marine current force at the same velocity and the influence of different groove arrangement on the stress of the riser are considered, the triangular groove texture is introduced into the riser surface to reduce the flow resistance of the riser by using the principle of texture drag reduction. Using large eddy numerical simulation, the mechanical model of triangular groove textured riser is established. The effects of geometric parameters of triangular groove depth and width on riser lift resistance coefficient, velocity field distribution, pressure coefficient distribution and vorticity distribution are simulated and analyzed at constant velocity. The velocity vector field distribution is compared. The results show that under the simulated condition of constant average velocity of 0.3 m/s in the South China Sea, when the number of triangular groove texture grooves is 32, the rise resistance coefficient of grooved texture riser is less than that of smooth riser, which plays the role of reducing resistance and restraining rise. When the depth is 0.14 mm and the width is 1.96 mm, the resistance coefficient of riser is reduced by 65.02% and the root mean square of lift coefficient is reduced by 78.3%. The drag reduction effect is the best. Based on this, a new method for optimal design and evaluation of flow drag reduction around triangular grooved riser at constant flow velocity is established, which provides a theoretical reference for improving the fatigue failure and service life of riser by using triangular grooved texture.