Experimental Investigation of Flat Plate Cryogenic Oscillating Heat Pipe

2019 ◽  
Vol 198 (1-2) ◽  
pp. 41-55 ◽  
Author(s):  
Vivek Patel ◽  
Nirvesh Mehta ◽  
Kamlesh Mehta ◽  
Amarish Badgujar ◽  
Shreya Mehta ◽  
...  
Author(s):  
Scott M. Thompson ◽  
Hongbin Ma ◽  
Robert A. Winholtz ◽  
Corey Wilson

An experimental investigation on the effects of condenser temperatures, heating modes and heat inputs on a miniature, three dimensional flat-plate oscillating heat pipe (3D FP-OHP) was conducted visually and thermally. The 3D FP-OHP was charged with acetone at a filling ratio of 0.80, had dimensions of 101.60 × 63.50 × 2.54 mm3, possessed 30 total turns, and had square channels on both sides of the device with a hydraulic diameter of 0.762 mm. Unlike traditional flat-plate designs, this new three-dimensional, compact design allows for multiple heating arrangements and higher heat fluxes. Transient and steady-state temperature measurements were collected at various heat inputs and the activation/start-up was clearly observed for both bottom and side heating modes during reception of its excitation power for this miniature 3D FP-OHP. The neutron imaging technology was simultaneously employed to observe the internal working fluid flow for all tests directly through the heat pipe’s copper wall. The activation was accompanied with a pronounced temperature field relaxation and the onset of chaotic thermal oscillations — all occurring with the same general oscillatory pattern at locations all around the 3D FP-OHP. Qualitative and quantitative analysis of these thermal oscillations, along with the presentation of the average temperature difference and thermal resistance, for all experimental conditions are provided. The novelty of the three-dimensional OHP design is its ability to still produce the oscillating motions of liquid plugs and vapor bubbles and, more importantly, its ability to remove higher heat fluxes.


Author(s):  
Aaron A. Hathaway ◽  
Hongbin Ma

An experimental investigation of the effect of filling ratio on the thermal performance for a flat plate oscillating heat pipe with uneven turns was conducted. The OHP was designed to have 14 long turns running from the evaporator to the condenser and 6 short turn occurring only in the evaporator. The factors varied for this experimental investigation were the input power, condensing temperature, and charging ratio. Experimental results show that for all test conditions, the OHP functioned very well and could operate with an input power of up to 1200 W and could reach a thermal resistance of 0.028 °C/W in the inverted position with a filling ratio of 70%.


2009 ◽  
Vol 131 (4) ◽  
Author(s):  
S. M. Thompson ◽  
H. B. Ma ◽  
R. A. Winholtz ◽  
C. Wilson

An experimental investigation on the effects of condenser temperatures, heating modes, and heat inputs on a miniature three-dimensional (3D) flat-plate oscillating heat pipe (FP-OHP) was conducted visually and thermally. The 3D FP-OHP was charged with acetone at a filling ratio of 0.80, had dimensions of 101.60×63.50×2.54 mm3, possessed 30 total turns, and had square channels on both sides of the device with a hydraulic diameter of 0.762 mm. Unlike traditional flat-plate designs, this new three-dimensional compact design allows for multiple heating arrangements and higher heat fluxes. Transient and steady-state temperature measurements were collected at various heat inputs, and the activation/start-up of the OHP was clearly observed for both bottom and side heating modes during reception of its excitation power for this miniature 3D FP-OHP. The neutron imaging technology was simultaneously employed to observe the internal working fluid flow for all tests directly through the copper wall. The activation was accompanied with a pronounced temperature field relaxation and the onset of chaotic thermal oscillations occurring with the same general oscillatory pattern at locations all around the 3D FP-OHP. Qualitative and quantitative analysis of these thermal oscillations, along with the presentation of the average temperature difference and thermal resistance, for all experimental conditions are provided. The novelty of the three-dimensional OHP design is its ability to still produce the oscillating motions of liquid plugs and vapor bubbles and, more importantly, its ability to remove higher heat fluxes.


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