Anti-PIV type 1 Monoclonal antibody, Clone 362/23B (QBS2)

The effect of topographic features on wind velocity and turbulence intensity was evaluated by conducting wind tunnel experiments with Particle Image Velocimetry (PIV) system. In this study, to simulate the natural wind characteristics, the active turbulence grids and boundary layer generation frame were installed in the wind tunnel. The mean wind velocity, the velocity vector diagram and the turbulence intensity around the two-dimensional single simplified models were investigated. As a result, the flow was separated at the simplified model tip in all cases of models, and the countercurrent flow field was generated at the downstream side. Moreover, the clockwise circulation flow also moved to the upstream side in the case of large radius R. RX was followed by the name given the radius value of X. For the mainstream turbulence intensity, the ranges of high turbulence intensity were z/H < 2.8 for R1 model, z/H < 2.6 for R3 model, z/H < 2.5 for R6 model, z/H < 2.4 for R11 model, z/H < 2.2 for R20 model, z/H < 2.0 for R23 model, z/H < 1.9 for R25 model in the vertical direction. The quantitative measurement results of this paper provided a database for the validation of the wind velocity distributions of atmospheric turbulent flow in the hill and mountain regions. (C) 2019 Elsevier Ltd. All rights reserved.

Measurements in the wake of a free-flying full-scale helicopter in ground effect were performed for both quasi-steady and unsteady maneuvering flights using stereoscopic particle image velocimetry (PIV), a time-resolved background-oriented schlieren (BOS) setup, and an optical marker tracking technique. The systems were used in a complementary way to both visualize blade tip vortices in a large portion of the rotor wake and to capture spatially resolved wake velocity data close to the ground. The high sensitivity of the BOS system enabled the detection of vortices up to an age of psi = 630 degrees. Different instabilitymechanisms as long-wave, short-wave, and pairing instabilities were observed with varying intensity for different flight conditions. A quantitative analysis of vortex locations showed a periodic variation resulting from interactions between consecutive vortices that led to vortex pairing. Characteristics of the wake outwash close to the ground were investigated by means of averaged velocity fields. Different patterns such aswall jet, recirculation, and ground vortex flowwere quantitatively analyzed and found to be in good agreement with previous model helicopter experiments. The instantaneous velocity data were used to detect individual blade tip vortices with ages above 450 degrees close to the ground and to extract vortex parameters. For a takeoff maneuver, both concentrated vortices and the formation of larger vortex structures due to bundling of several vortices were observed.