Pan Zhao, Whitehead Jared, Thomson Scott, Truscott Tadd
Department of Mechanical Engineering, Brigham Young University, UT, USA.
Mathematics Department, Brigham Young University, UT, USA.
Meas Sci Technol. 2016 Aug;27(8):084012. doi: 10.1088/0957-0233/27/8/084012. Epub 2016 Jul 6.
Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this technique generally involves integrating the pressure gradient or solving the pressure Poisson equation using a velocity field measured with PIV. However, very little research has been done to investigate the dynamics of error propagation from PIV-based velocity measurements to the pressure field calculation. Rather than measure the error through experiment, we investigate the dynamics of the error propagation by examining the Poisson equation directly. We analytically quantify the error bound in the pressure field, and are able to illustrate the mathematical roots of why and how the Poisson equation based pressure calculation propagates error from the PIV data. The results show that the error depends on the shape and type of boundary conditions, the dimensions of the flow domain, and the flow type.
由于粒子图像测速技术(PIV)具有非侵入性,从该技术获取压力场数据在流体动力学中是一项颇具吸引力的技术。这项技术的应用通常涉及对压力梯度进行积分,或者使用PIV测量的速度场求解压力泊松方程。然而,对于基于PIV的速度测量到压力场计算的误差传播动态的研究却非常少。我们不是通过实验来测量误差,而是直接通过研究泊松方程来探究误差传播的动态过程。我们通过分析量化了压力场中的误差界限,并且能够阐明基于泊松方程的压力计算为何以及如何从PIV数据传播误差的数学根源。结果表明,误差取决于边界条件的形状和类型、流动域的尺寸以及流动类型。