Cold-thermal wake characteristics of submarine in temperature-density stratified seawater

2019 ◽  
Author(s):  
Richa Hu ◽  
Chunlong Liu ◽  
Xusheng Zhang ◽  
Liang Guo
Keyword(s):  
Thermal Wake ◽  
Wake Characteristics

Experimental investigation on the momentumless wake using trailing edge blowing

2008 ◽  
Vol 222 (8) ◽  
pp. 1477-1486 ◽  
Author(s):  
Y Wu ◽  
X Zhu ◽  
Z Du
Keyword(s):  
Three Dimensional ◽  
Velocity Profiles ◽  
Axial Fan ◽  
Trailing Edge ◽  
Mean Velocity ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Velocity Spectra ◽  
Momentumless Wake ◽  
Wake Characteristics

A developed plate stator model with and without trailing edge blowing (TEB) is studied using experimental methods. Wake characteristics of flow over the stator in the three-dimensional wake regimes are studied using hot-wire anemometry (HWA) and particle image velocimetry (PIV) techniques. First, the mean velocity profiles have been measured in the wake of the stator using HWA. Four wake characteristics have been obtained through momentum thickness judgments: pure wake, weak wake, momentumless wake, and jet. These velocity profiles show some differences in momentum deficit for the four cases. Then, the velocity spectra of the pure wake and momentumless wake obtained through the HWA measurements showed that TEB can eliminate the shedding vortex of the stator. Characteristic length scales based on the wake turbulent intensity profiles showed that the momentumless wake can reduce the wake width and depth. PIV measurement is carried out to measure the flow field of the four wakes. Finally, the application of TEB approaching momentumless wake status is used on an industrial ventilation low-pressure axial fan to assess noise reduction. The results show that TEB can make the outlet of the stator uniform, reduce velocity fluctuation, destroy the vorticity structure downstream of the stator, and reduce interaction noise level of the stator and rotor.

Unsteady Wake Characteristics of a Flapping Wing through 3D TR-PIV

2012 ◽  
Vol 25 (4) ◽  
pp. 547-558 ◽  
Author(s):  
Saurav Kumar Ghosh ◽  
Chandrala Lakshmana Dora ◽  
Debopam Das
Keyword(s):  
Flapping Wing ◽  
Unsteady Wake ◽  
Wake Characteristics

Experimental investigation of the wake characteristics behind twin vertical axis turbines

2021 ◽  
Vol 247 ◽  
pp. 114768
Author(s):  
Stephanie Müller ◽  
Valentine Muhawenimana ◽  
Catherine A.M.E. Wilson ◽  
Pablo Ouro
Keyword(s):  
Experimental Investigation ◽  
Vertical Axis ◽  
Wake Characteristics

The Effects of Fish Cages on Ambient Currents

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Lars C. Gansel ◽  
Thomas A. McClimans ◽  
Dag Myrhaug
Keyword(s):  
Drag Force ◽  
Particle Image ◽  
Reynolds Numbers ◽  
Strain Gauges ◽  
Metal Mesh ◽  
Image Velocimetry ◽  
Flow Through ◽  
Fish Cages ◽  
Ambient Currents ◽  
Wake Characteristics

Experiments were carried out to measure forces on and wake characteristics downstream from fish cages. Cylinders made from metal mesh with porosities of 0%, 30%, 60%, 75%, 82%, and 90% were tested in a towing tank. The drag force was measured with strain gauges, and the flow field downstream from the models was analyzed using particle image velocimetry. The Reynolds numbers ranged from 1000–20,000 based on the model diameter and 15–300 based on the diameter of the strings of the mesh as an independent obstacle. High porosities (here, 82% and 90%) lead to low water blockage and allow a substantial amount of water to flow through the model. The data indicate that the wake characteristics change toward the wake characteristics of a solid cylinder at a porosity just below 75%. The drag force is highly dependent on the porosity for high porosities of a cylinder.

scholarly journals Thermal Wake Studies During the August 21st 2017 Total Solar Eclipse

2017 ◽  
Author(s):  
Alynie Xiong ◽  
Ana Taylor ◽  
Brittany Craig ◽  
Erick Paul Agrimson ◽  
Gordon McIntosh ◽  
...  
Keyword(s):  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Thermal Wake
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