Evaluation of a Dynamic Positioning Thruster Wake Using Laser Doppler Velocimetry

2004 ◽  
Author(s):  
Said El-Lababidy ◽  
Neil Bose ◽  
Pengfei Liu
Keyword(s):  
Laser Doppler Velocimetry ◽  
Diameter Ratio ◽  
Operating Conditions ◽  
Laser Doppler ◽  
Hydrodynamic Characteristics ◽  
Dynamic Positioning ◽  
Doppler Velocimetry ◽  
Near Wake ◽  
Ducted Propeller ◽  
Cavitation Tunnel

To provide information on the wake characteristics of Dynamic Positioning (DP) thrusters when operating with and without a nozzle under varied operating conditions, experiments were done on a ducted propeller model in a cavitation tunnel. The propeller flow field was measured with a two-component Laser Doppler Velocimetry (LDV) system, up to 1.5 diameters downstream. These experiments were carried out with and without the nozzle, and the results are presented here for a pitch/diameter ratio of 1.2 and an advance coefficient of 0.4. This paper shows and compares the results of the DP thruster near wake hydrodynamic characteristics obtained by the LDV system when operating with and without a nozzle.

Dynamic Positioning Thruster Near Wake Hydrodynamic Characteristics at Near Bollard Pull

2009 ◽  
Vol 53 (01) ◽  
pp. 48-58
Author(s):  
Said A. El Lababidy ◽  
Neil Bose ◽  
Pengfei Liu ◽  
Dan Walker
Keyword(s):  
System Reliability ◽  
Laser Doppler Velocimetry ◽  
Diameter Ratio ◽  
Operating Conditions ◽  
Hydrodynamic Characteristics ◽  
Dynamic Positioning ◽  
Doppler Velocimetry ◽  
Near Wake ◽  
Two Component ◽  
Cavitation Tunnel

The knowledge of the hydrodynamic characteristics and momentum effects of the flow of dynamic positioning (DP) thrusters are important factors in the design of structures around the DP thrusters and in improving DP system reliability. In the present study, the flow field around a DP thruster model was precisely measured in a cavitation tunnel using a two-component laser Doppler velocimetry (LDV) system. These experiments were carried out with and without a nozzle at three different axial planes up to 1.5 diameters downstream, and the results are presented here for a pitch/diameter ratio of 1.2 at near bollard pull operating conditions (J ¼ 0.4 and J ¼ 0.45). This paper shows and compares the results of the DP thruster near wake hydrodynamic and momentum characteristics when operating with and without a nozzle at two different low advance coefficient values.

Detailed Analysis of the Wake of a DP Thruster Emphasizing Comparison Between LDV and SPIV Techniques

2005 ◽  
Vol 128 (2) ◽  
pp. 81-88
Author(s):  
S. El Lababidy ◽  
N. Bose ◽  
P. Liu ◽  
F. Di Felice
Keyword(s):  
Detailed Analysis ◽  
Laser Doppler Velocimetry ◽  
Particle Image ◽  
Operating Conditions ◽  
Stereoscopic Particle Image Velocimetry ◽  
Hydrodynamic Characteristics ◽  
Dynamic Positioning ◽  
Doppler Velocimetry ◽  
Image Velocimetry ◽  
Variable Operating Conditions

To provide experimental data on the hydrodynamic characteristics and features of dynamic positioning (DP) thrusters under variable operating conditions, wake measurements were performed on a DP thruster model using 2D laser Doppler velocimetry (LDV) and stereoscopic particle image velocimetry (SPIV). These tests were performed with and without a nozzle and over a range of advance coefficient values including the bollard pull condition. In this paper, a detailed analysis of the hydrodynamic characteristics of the wake at a plane equal to a distance of 0.5 diameters downstream from the thruster, at advance coefficient values of 0, 0.4, and 0.45 are presented for both the LDV and SPIV measurements showing a comparison between the results of each technique. The effect of the duct and of changes in the advance coefficient values is presented in this paper.

Development of LDV(Laser Doppler Velocimetry) for Measuring Three Dimensional Hull Wake of Ship Model in Large Cavitation Tunnel

2017 ◽  
Vol 54 (6) ◽  
pp. 515-521 ◽  
Author(s):  
Bu-Geun Paik ◽  
Jong-Woo Ahn ◽  
Han-Shin Seol ◽  
Young-Ha Park ◽  
Ki-Sup Kim ◽  
...  
Keyword(s):  
Laser Doppler Velocimetry ◽  
Three Dimensional ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Ship Model ◽  
Cavitation Tunnel

scholarly journals Investigation of Internal Flow in Centrifugal Pump Diffuser using Laser Doppler Velocimetry (LDV) and Computational Fluid Dynamics

2021 ◽  
Vol 1909 (1) ◽  
pp. 012075
Author(s):  
Daisuke Sugiyama ◽  
Asuma Ichinose ◽  
Tomoki Takeda ◽  
Kazuyoshi Miyagawa ◽  
Hideyo Negishi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Pump ◽  
Laser Doppler Velocimetry ◽  
Internal Flow ◽  
Laser Doppler ◽  
Doppler Velocimetry

scholarly journals Laser-Doppler Velocimetry Measurements Inside a Backward Curved Centrifugal Fan

2001 ◽  
Vol 7 (3) ◽  
pp. 173-181
Author(s):  
Tong-Miin Liou ◽  
Meng-Yu Chen
Keyword(s):  
Flow Rate ◽  
Turbulence Intensity ◽  
Laser Doppler Velocimetry ◽  
Reverse Flow ◽  
Flow Region ◽  
Design Flow ◽  
Laser Doppler ◽  
Centrifugal Fan ◽  
Doppler Velocimetry ◽  
Flow Rates

Laser-Doppler velocimetry (LDV) measurements are presented of relative mean velocity and turbulence intensity components inside the impeller passage of a centrifugal fan with twelve backward curved blades at design, under-design, and over-design flow rates. Additional LDV measurements were also performed at the volute outlet to examine the uniformity of the outlet flow for the three selected flow rates. Complementary flow visualization results in the tongue region are further presented. It is found that the number of characteristic flow regions and the average turbulence level increase with decreasing air flow rate. For the case of under-design flow rate, there are a through-flow region on the suction side, a reverse flow region on the pressure side, and a shear layer region in between. The corresponding average turbulence intensity is as high as 9.1% of blade tip velocity.

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