运输机升阻特性仿真与风洞试验相关性方法

Correlation Method between Lift-drag Characteristic Simulation and Wind Tunnel Test of Transport Aircraft

为利用数值模拟方法获取带动力运输机的升阻特性,以M3飞机配装某型发动机三维模型为研究对象,采用数值仿真(computational fluid dynamics,CFD)方法对整机流场进行数值计算。对于带动力短舱模型,利用分区拼接网格技术对发动机内流场和飞机外流场进行网格划分和拼接;在此基础上采用雷诺平均N-S方程,基于S-A湍流模型,开展了不同发动机状态、马赫数及攻角的仿真计算。以风扇压比FNPR=1.61时,试验获得的升阻系数作为基准,在不同攻角下,获得CFD计算结果的修正因子,结果表明:修正后的数值计算结果与风洞试验获取的升力特性曲线,贴合程度好,在攻角小于14°内误差小于3%;修正后的阻力特性曲线整体趋势与风洞试验一致,误差小于10%,阻力系数都是随攻角的增大而增大,且在攻角大于10°后快速增大。该相关性方法研究为后续确定带动力运输机升阻特性提供技术支持。

In order to obtain the lift-drag characteristics of the powered conveyor by using the numerical simulation method,the M3 aircraft was equipped with a three-dimensional model of a certain type of engine as the research object,and the computational fluid dynamics(CFD)method was used to carry out numerical calculations on the entire flow field.For the powered nacelle model,the partitioned stitching grid technology was used to mesh and splice the internal and external flow fields of the engine.On this basis,reynolds mean equation(N-S)and S-A turbulence model were used to calculate the flow field of three different Ma,different engine state and different angles of attack.Under the state of FNPR=1.61,the lift and drag fright obtained by the experiment was used as a reference,and the correction factor of the CFD calculation result was obtained under different angles of attack.The results show that the revised numerical calculation results fit well with the lift characteristic curve measured by the wind tunnel test.The error was less than 3%within 14 degree.The overall trend of the modified resistance characteristic curve was consistent with the wind tunnel test,with an error of less than 10%,and the resistance curves increase the angle of attack,and increase rapidly after the angle of attack,and increase rapidly after the angle of attack was greater than 10 degree.The correlation method research provides technical support for the subsequent determination of the lift-drag characteristics of the powered transport aircraft.