GPU-based, parallel-line, omni-directional integration of measured pressure gradient field to obtain the 3D pressure distribution
GPU-based, parallel-line, omni-directional integration of measured pressure gradient field to obtain the 3D pressure distribution
复制标题
基于GPU对实测压力梯度场进行并行、全方位积分，获得3D压力分布
DOI：
10.1007/s00348-019-2700-y
复制
发表时间：
2019
影响因子：
2.4
通讯作者：
J. Katz
中科院分区：
文献类型：
--
作者：
Jin Wang;Cao Zhang;J. Katz
3D时间分辨速度测量技术的引入，可以通过空间积分材料加速度来计算瞬时压力分布。本文介绍了一种有效的三维加速度积分方法，该方法不需要在某一个曲面上规定Dirichlet边界条件，使加速度误差的传播最小化，并且易于用于具有复杂边界的流动。这种平行线全方位积分程序（Omni3D）通过从各个方向积分计算每个点的压力，同时避免了加速度误差较大的区域。为了降低计算成本，计算采用基于gpu的算法，该算法在1分钟内从层析PIV数据确定三维压力场。将Omni3D的精度与几种技术进行了比较，包括基于求解具有不同Dirichlet边界条件的压力泊松方程（PPE）的方法。误差分析基于各向同性湍流的直接数值模拟（DNS）数据、由DNS数据生成的湍流通道流合成三维PIV图像以及实验数据。它检查了空间分辨率，传播，避免嵌入的局部误差，边界条件，计算速度的方法，以及粘性和亚网格应力对计算压力的影响。对于低误差和适当指定边界条件的加速度场，Omni3D和PPE给出了相似的结果。然而，Omni3D在抑制加速度误差的影响方面更有效。给出了基于层析PIV数据的压力瞬时图、压力统计和压力-速度相关性的实验结果。
The introduction of 3D time-resolved velocity measurement techniques enables calculation of the instantaneous pressure distribution by spatially integrating the material acceleration. This paper introduces an efficient method for 3D integration of the acceleration, which does not require prescribed Dirichlet boundary condition on one of the surfaces, minimizes the propagation of errors in acceleration, and can be easily utilized in flows with complex boundaries. This parallel-line, omni-directional integration procedure (Omni3D) calculates the pressure at every point by integration from all directions, while avoiding regions with large acceleration errors. To reduce the computational costs, the calculations are performed by a GPU-based algorithm, which determines the 3D pressure field from tomographic PIV data in 1 min. The accuracy of Omni3D is compared to that of several techniques, including procedures based on solving the Pressure Poisson Equation (PPE) with different Dirichlet boundary conditions. The error analysis is based on Direct Numerical Simulation (DNS) data for isotropic turbulence, synthetic 3D PIV images for turbulent channel flow generated from DNS data, and experimental data. It examines the effects of spatial resolution, propagation, and avoidance of embedded local errors, boundary conditions, method for calculating the velocity, as well as viscous and sub-grid stresses on the calculated pressures. For acceleration fields with low errors and properly specified boundary conditions, Omni3D and PPE give similar results. However, Omni3D is more effective in suppressing the effects of acceleration errors. Sample experimental results including instantaneous plot of pressure, pressure statistics, and pressure–velocity correlations based on tomographic PIV data are also provided.