PIV measurements in environmental flows: Recent experiences at the Institute for Hydromechanics in Karlsruhe

Abstract

Particle-Image-Velocimetry (PIV) has been applied to many different environmental flows in the last twelve years at the Institute for Hydromechanics, Karlsruhe Institute of Technology. The present paper gives an overview about the most important results gained with PIV during this period and summarizes the advantages and disadvantages of this measurement technique. PIV applications to determine velocities at the water surface as well as internal flows characteristics are discussed with respect to physical and technical aspects. It can be concluded that PIV is still not a standard tool, every application needs adaptation and comprises certain limitations. Every element of the measurement system (window size, camera, spatial and temporal resolution, etc.) has to fit exactly the physical problem to be examined. Ó

The structure of gravel‐bed flow with intermediate submergence: A laboratory study

“…However, for better understanding of measurement errors in our PIV data, a spectral analysis was conducted as suggested in Detert []. Based on his method, the quality of measured PIV data can be estimated by the ratio of the resolved (measured) turbulent energy to the total turbulent energy [ Detert et al ., ; Weitbrecht et al ., ]. The resolved turbulent energy is estimated from the area under the experimental spectral curves while the total turbulence intensity can be obtained by extrapolation of experimental spectra to Kolmogorov length scale [ Lavoie et al ., ].…”

A preliminary study on the active cold seeps flow field in the Qiongdongnan Sea Area, the northern South China Sea

“…(1) PIV技术自20世纪被提出以来 [36] , 已经在流场 测量中得到了广泛应用 [48,53] , 目前已经发展了互相关 算法 [54] 、光流法 [55,56] 等一系列算法, 成为光学测速流 场研究中最为广泛的一种技术 [53,57] .…”

Purification of bathing wastewater by double suspended layer fluidized bed reactor

“…It is based on the rapid advancement of digital image capture and processing techniques and computers. The primary assumption of PIV is that the movement of seeding particles or the movement of the intensity pattern of the images precisely reflects the local velocity of the observed medium (Weitbrecht et al 2011). PIV can realize transient measurements of the entire flow field and obtain other physical flow field parameters.…”