输气管道肋条减阻数值模拟

Numerical Simulation of Drag Reduction of Gas Pipeline

湍流阻力是长距离输气管道中能量损失的主要因素。为了研究V型肋条在输气管道中对阻力的影响,在雷诺数为74 880的条件下,采用CFD软件对光滑管道和内壁铺有尺寸不同的两种肋条的管道进行了数值模拟,并通过分析管道中的流场、涡量和壁面切应力的分布规律,找出两种尺寸肋条增阻和减阻的原因,得出肋条减阻的机理。结果表明,与光滑圆管相比,管道中的肋条尺寸s+=22时,近壁区流体流速小,涡量小,壁面切应力增阻区面积小,切应力小,具有减阻效果;当管道中的肋条尺寸s+=44时,近壁区流体流速大,肋顶处涡量较大,壁面切应力增阻区面积大,切应力大,肋条具有增阻效果。

The most important form of loss of energy in long-distance gas pipelines was turbulence resistance.In order to study the V-shaped riblet influence on the resistance in the gas pipeline,this paper used the software of CFD to simulate two different geometric size of V-shaped riblets and smooth pipe.The Reynolds number was 74 880.By analyzing the flow field in the pipeline,the distribution of vorticity and wall shear stress,the reasons for increasing drag and decreasing resistance were found.Based on this,the drag reduction mechanism was obtained.The results showed that：compared with the smooth gas transmission pipeline,when the riblet size in the pipeline was s＋=22,the flow velocity,vorticity value,the area of wall shear stress and the shear stress were small.Riblet had the effect of drag reduction.When the riblet size of the pipeline was s＋=44,the flow velocity of the near wall area,the vorticity value at the top of the riblet,the wall shear stress increased area and the shear stress value was large.Riblet had the effect of increasing resistance.