Numerical and Experimental Investigations of HAWT Near Wake Predictions using Particle Image Velocimetry and Actuator Disk Method

This paper presents experimental investigations conducted to understand the influence of water-soluble drag-reducing polymers (DRPs) in single- and two-phase (stratified wavy) flow on flow-field characteristics. These experiments have been presented for water and air–water flowing in a horizontal polyvinyl chloride 22.5-mm ID, 8.33-m long pipe. The effects of liquid flow rates and DRP concentrations on streamlines and the instantaneous velocity were investigated by using particle image velocimetry (PIV) technique. A comparison of the PIV results was performed by comparing them with the computational results obtained by fluent software. One of the comparisons has been done between the PIV results, where a turbulent flow with DRP was examined, and the laminar–computational fluid dynamic (CFD) prediction. An agreement was found in the region near the pipe wall in some cases. The results showed the powerfulness of using the PIV techniques in understanding the mechanism of DRP in single- and two-phase flow especially at the regions near the pipe wall and near the phases interface. The results of this study indicate that an increase in DRP concentrations results in an increase in drag reduction up to 45% in single-phase water flow and up to 42% in air–water stratified flow.

Download Full-text

Analytical and experimental investigations of dual‐plane particle image velocimetry

Optical Engineering ◽

10.1117/1.600695 ◽

1996 ◽

Vol 35 (7) ◽

pp. 2067 ◽

Cited By ~ 15

Author(s):

Markus Raffel

Keyword(s):

Particle Image Velocimetry ◽

Particle Image ◽

Experimental Investigations ◽

Dual Plane ◽

Image Velocimetry

Download Full-text

Experimental Analysis of the Near Wake from a Ducted Thruster at True and Near Bollard Pull Conditions Using Stereo Particle Image Velocimetry (SPIV)

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.1951770 ◽

2005 ◽

Vol 127 (3) ◽

pp. 191-196 ◽

Cited By ~ 4

Author(s):

S. El Lababidy ◽

N. Bose ◽

P. Liu ◽

D. Walker ◽

F. Di Felice

Keyword(s):

Particle Image Velocimetry ◽

Particle Image ◽

Practical Interest ◽

Stereoscopic Particle Image Velocimetry ◽

Wake Flow ◽

Hydrodynamic Characteristics ◽

Near Wake ◽

Image Velocimetry ◽

Wide Range ◽

Marine Applications

Thrusters working at low advance coefficients are employed in a wide range of offshore and marine applications on Floating, Production, Storage, and Offloading (FPSO) systems; shuttle tankers; tug boats; and mobile offshore units. Therefore, an understanding of the flow around the thrusters is of great practical interest. Despite this interest, there is lack of knowledge in the description of the hydrodynamic characteristics of a ducted thruster’s wake at bollard pull and low advance coefficient values. This work was aimed at providing detailed data about the hydrodynamic characteristics of a Dynamic Positioning (DP) thruster near wake flow at different low advance coefficient values. Wake measurements were made during cavitation tunnel tests carried out on a ducted propeller model at the Italian Ship Model Basin (INSEAN), Rome, Italy. Through these experiments, the DP thruster near wake velocity components at different downstream axial planes, up to 1.5 diameters downstream, were obtained using a Stereoscopic Particle Image Velocimetry (SPIV) system. These experiments were carried out at different advance coefficient (J) values [bollard pull (J=0), J=0.4 and J=0.45].

Download Full-text