Robust Thermal Performance of a Flat-Plate Oscillating Heat Pipe During High-Gravity Loading

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
S. M. Thompson ◽  
A. A. Hathaway ◽  
C. D. Smoot ◽  
C. A. Wilson ◽  
H. B. Ma ◽  
...  
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Heat Transfer Performance ◽  
Unique Feature ◽  
Three Dimensional ◽  
High Gravity ◽  
Oscillating Heat Pipe ◽  
Novel Design ◽  
Independent Heat

The thermal performance of a miniature, three-dimensional flat-plate oscillating heat pipe (3D FP-OHP) was experimentally investigated during high-gravity loading with nonfavorable evaporator positioning. The heat pipe had dimensions of 3.0 × 3.0 × 0.254 cm3 and utilized a novel design concept incorporating a two-layer channel arrangement. The device was charged with acetone and tested at a heat input of 95 W within a spin-table centrifuge. It was found that the heat pipe operated and performed near-independent of the investigated hypergravity loading up to 10 g. Results show that at ten times the acceleration due to gravity (10 g), the effective thermal conductivity was almost constant and even slightly increased which is very different from a conventional heat pipe. The gravity-independent heat transfer performance provides a unique feature of OHPs.

Experimental Investigation of a Flat-Plate Oscillating Heat Pipe During High-Gravity Loading

2011 ◽  
Author(s):  
Hongbin Ma ◽  
Scott M. Thompson ◽  
Aaron A. Hathaway ◽  
Chris D. Smoot ◽  
Corey A. Wilson ◽  
...  
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Unique Feature ◽  
Three Dimensional ◽  
High Gravity ◽  
Transfer Performance ◽  
Oscillating Heat Pipe ◽  
Novel Design ◽  
Independent Heat

The thermal performance of a miniature, three-dimensional flat-plate oscillating heat pipe (3D FP-OHP) was experimentally investigated during high gravity loading with non-favorable evaporator positioning. The heat pipe had dimensions of 3.0 × 3.0 × 0.254 cm3 and utilized a novel design concept incorporating a two-layer channel arrangement. The device was charged with acetone and tested at a heat input of 95 W within a spin-table centrifuge. It was found that the heat pipe operated and performed near-independent of the investigated hyper-gravity loading up to 10g. Results show that at ten times the acceleration due to gravity (10g) the effective thermal conductivity was almost constant and even slightly increased which is very different from a conventional heat pipe. The gravity-independent heat transfer performance provides a unique feature of OHPs.

An Experimental Investigation of Three-Dimensional Flat-Plate Oscillating Heat Pipe

2009 ◽  
Author(s):  
Scott M. Thompson ◽  
Hongbin Ma ◽  
Robert A. Winholtz ◽  
Corey Wilson
Keyword(s):  
Experimental Investigation ◽  
Flat Plate ◽  
Heat Pipe ◽  
Three Dimensional ◽  
Neutron Imaging ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Oscillating Heat Pipe ◽  
Oscillatory Pattern ◽  
Thermal Oscillations

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.

Effect of Filling Ratio on an Uneven Turn Oscillating Heat Pipe

2011 ◽  
Author(s):  
Aaron A. Hathaway ◽  
Hongbin Ma
Keyword(s):  
Experimental Investigation ◽  
Thermal Resistance ◽  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Input Power ◽  
Filling Ratio ◽  
Inverted Position ◽  
Oscillating Heat Pipe ◽  
Test Conditions

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%.

Effect of Operational Parameters on the Thermal Performance of Flat Plate Oscillating Heat Pipe

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Kamlesh K. Mehta ◽  
Nirvesh Mehta ◽  
Vivek Patel
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Charge Ratio ◽  
Working Fluid ◽  
Operational Parameters ◽  
Oscillating Heat Pipe ◽  
Transfer Device

Abstract Flat plate oscillating heat pipe (FP-OHP) is a unique heat transfer device and considered as a promising candidate for effective heat transfer device in electronics industries. A number of theoretical studies and experimental investigations have been carried out on FP-OHP in the past decades after its invention. However, due to the operational characteristics of FP-OHP, the effect of various parameters on the thermal performance of FP-OHP has not been completely revealed so far. This paper attempts to discuss the effect of operational parameters on the thermal performance of FP-OHP. In this study, the FP-OHP was investigated with different charge ratios, orientations, working fluids, and heat loads from 10 W to 150 W. In order to investigate the effect, 18 parallel square channels of 2 × 2 mm2 are machined onto pure copper plate (93 × 70 × 8 mm3) to form FP-OHP. DI water, ethanol, methanol, acetone, and FC-72 are investigated. The measured thermal resistance was strongly dependent on operational parameters. The optimum performance was observed with acetone with a charge ratio of 70% in the vertical orientation. The lowest thermal resistance of 0.39 °C/W is achieved using acetone as a working fluid at 100 W. A Kutateladze number (Ku) was used to compare the experimental data and found to be suitable for prediction of the thermal performance of FP-OHP with standard deviation of 15%.

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