采用计算流体力学(Computational fluid dynamics,CFD)的方法模拟致动盘,研究了尾流边界的发展过程。为了准确捕捉尾流边界细节,根据尾流边界的速度梯度远远大于流场中的其他区域的速度梯度的特性,使用自适应弹簧网格技术,使网格的最密区域始终跟随尾流边界运动。基于该数值模拟结果建立了一个尾流边界模型。该模型将尾流的发展分为与粘性无关的膨胀过程和与粘性相关的扩散过程,建模结果与实验结果吻合。在此基础上,还利用该模型对高斯分布预测(Gaussian distribution prediction,GDP)尾流模型进行了修正,使其更加准确。
The development of the wake boundary after an actuator disc is simulated using the computational fluid dynamics(CFD) method.To capture the details of wake boundary,the adaptive spring-mesh technique is used to make the finest meshes always follow the wake boundary movement,according to the fact that the velocity gradient in the wake boundary is much larger than in other regions.A wake boundary model has been developed based on the CFD results.This model divides the wake development into the expanding process due to inviscid flow and the diffusing process due to viscous influence.The reliability of the model is validated by comparing with experimental data.As a demonstration of application,a newly developed wake velocity model called Gaussian distribution prediction(GDP) model is improved by the present wake boundary model.