在高温环烷酸腐蚀环境中，应用Fluent软件对不同结构尺寸的异径偏心弯管弯头与变径后直管段内的流场进行了数值模拟。根据流速、剪切力等流体力学参数的变化情况，结合高温环烷酸腐蚀机理，分析了流场对异径偏心弯管冲蚀的影响，预测并验证了异径偏心弯管易腐蚀的部位。结果表明：异径偏心弯管弯头两侧与外侧还有变径后直管段180°~360°附近壁面上的剪切力较大，易发生环烷酸冲蚀；弯头内侧剪切力随直管段长度增大而增大，弯头两侧剪切力随直管段长度增大而减小，弯头外侧剪切力不随直管段长度改变而改变。因此，在实际检测中，对于直管段较长的异径偏心弯管，除了弯头两侧与外侧，还要注意弯头内侧的检查。

In the environment of high temperature naphthenic corrosion, the flow distribution in the straight parts and elbow parts of eccentric reducing elbow pipes in different structures and sizes was analyzed using software of Fluent. The change of flow velocity and wall shear stress in eccentric reducing elbow was analyzed in conjunction with the high temperature erosion mechanism of naphthenic acid, to show how the erosion-corrosion in eccentric reducing elbow was influenced by flow distribution, and to predict and verify the places easily corroded. The results show that elevated levels of shear stress were found along the elbow lateral, elbow extrados and the 180°~360° of the straight pipe after the reducer, where naphthenic acid erosion-corrosion easily occured. With the increase of the straight pipe length, the shear stress in elbow intrados increased, the shear stress in elbow lateral decreased, the shear stress in elbow extrados did not change. Therefore in the actual testing, not only the elbow lateral and extrados but also the elbow intrados are necessary to be checked for eccentric reducing elbow with long straight pipe.