Effect of nanofluid on the heat transport capability in an oscillating heat pipe

2006 ◽  
Vol 88 (14) ◽  
pp. 143116 ◽  
Author(s):  
H. B. Ma ◽  
C. Wilson ◽  
B. Borgmeyer ◽  
K. Park ◽  
Q. Yu ◽  
...  
Keyword(s):  
Heat Pipe ◽  
Heat Transport ◽  
Oscillating Heat Pipe ◽  
Heat Transport Capability

Experimental Investigation of Ultrasonic Frequency Effect on an Oscillating Heat Pipe

2016 ◽  
Author(s):  
Nannan Zhao ◽  
Benwei Fu ◽  
Hongbin Ma ◽  
Fengmin Su
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transport ◽  
Frequency Effect ◽  
Ultrasonic Frequency ◽  
Sound Effect ◽  
Oscillating Heat Pipe ◽  
Ultrasonic Sound ◽  
Heat Transfer Capacity ◽  
Heat Transport Capability

The heat transport capability in an oscillating heat pipe (OHP) significantly depends on the oscillating frequency. An external frequency directly affects the natural frequency in the system. In this investigation, the ultrasound sound effect on the heat transport capability in an OHP was conducted with focus on the ultrasonic frequency effect on the oscillating motion and heat transfer capacity in an OHP. The ultrasonic sound was applied to the evaporating section of the OHP by using the electrically-controlled piezoelectric ceramics. The heat pipe was tested with or without the ultrasonic sound with different frequencies. In addition, the effects of operating temperature, heat load from 25 W to 150 W were investigated. The experimental results demonstrate that the heat transfer capacity enhancement of the OHP depends on the frequency of the ultrasound field, and there exists an optimum combination of the frequencies which will lead to the largest enhancement of the heat transfer capacity of the OHP.

Experimental Investigation of a Three-Layer Oscillating Heat Pipe

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
C. D. Smoot ◽  
H. B. Ma
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Effective Thermal Conductivity ◽  
Heat Transport ◽  
Total Power ◽  
Oscillating Heat Pipe ◽  
Layer Effect ◽  
Layering Effect ◽  
Heat Transport Capability

An experimental investigation of a compact, triple-layer oscillating heat pipe (OHP) has been conducted to determine the channel layer effect on the heat transport capability in an OHP. The OHP has dimensions 13 mm thick, 229 mm long, and 76 mm wide embedded with two-independent closed loops forming three layers of channels. The unique design of the investigated OHP can be readily used to explore the channel layering effect on the heat transport capability in the OHP. The experimental results show that the addition of channel layers can increase the total power and at the same time, it can increase the effective thermal conductivity of the OHP. When the OHP switches from one layer of channels to two layers of channels, the highest effective thermal conductivity can be increased from 5760 W/mK to 26,560 W/mK. At the same time, the dryout limit can be increased. With three layers of channels, the OHP investigated herein can transport a power up to 8 kW with a heat flux level of 103 W/cm2 achieving an effective thermal conductivity of 33,170 W/mK.

Effect of Al2O3 Microparticles on the Heat Transport Capability in an Oscillating Heat Pipe

2007 ◽  
Author(s):  
Hongtao Gao ◽  
Xiangyang Gao ◽  
Hongbin Ma ◽  
Anjun Jiao
Keyword(s):  
Heat Pipe ◽  
Heat Transport ◽  
Volume Ratio ◽  
Working Fluid ◽  
Transport Capacity ◽  
Oscillating Heat Pipe ◽  
Copper Tubing ◽  
Oscillating Motion ◽  
Heat Transport Capability ◽  
Adiabatic Section

An experimental investigation was conducted to determine the microparticle effect on the heat transport capability of an oscillating heat pipe (OHP). The OHP was fabricated from copper tubing with inside diameter of 1.52 mm. The heat pipe consists of the evaporator, adiabatic section, and condenser. When heat load was added to the evaporator of OHP, the strong oscillating motion was generated. Due to the strong oscillation and circulation motions, the heat transport capability of OHP was significantly increased. The experimental results show that there exists an optimum volume ratio of microparticles added into the working fluid. The effects of filling ratio and tilted angle on the heat transport capacity were also conducted.

Effect of Hydrophilic Nanostructured Cupric Oxide Surfaces on the Heat Transport Capability of a Flat-Plate Oscillating Heat Pipe

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
F. Z. Zhang ◽  
R. A. Winholtz ◽  
W. J. Black ◽  
M. R. Wilson ◽  
H. Taub ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Flat Plate ◽  
Heat Pipe ◽  
Heat Transport ◽  
Thermal Performance ◽  
Cupric Oxide ◽  
Neutron Imaging ◽  
Oscillating Heat Pipe ◽  
Heat Transport Capability ◽  
Insight Into

With a surface treatment of hydrophilic cupric oxide (CuO) nanostructures on the channels inside a flat-plate oscillating heat pipe (FP-OHP), the wetting effect on the thermal performance of an FP-OHP was experimentally investigated. Three FP-OHP configurations were tested: (1) evaporator treated, (2) condenser treated, and (3) untreated. Both evaporator- and condenser-treated FP-OHPs show significantly enhanced performance. The greatest improvement was seen in the condenser-treated FP-OHP, a 60% increase in thermal performance. Neutron imaging provided insight into the fluid dynamics inside the FP-OHPs. These findings show that hydrophilic nanostructures and their placement play a key role in an OHP's performance.

An Experimental Investigation of an Oscillating Heat Pipe Heat Spreader

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
F. F. Laun ◽  
H. Lu ◽  
H. B. Ma
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Heat Transport ◽  
Power Input ◽  
Heat Spreader ◽  
Oscillating Heat Pipe ◽  
Test Configuration ◽  
Central Heating ◽  
Center Section ◽  
Heat Transport Capability

With ever increasing technological advances in electronics, modern computer components continue to produce higher power densities that present a challenge to thermal management. A radial flat-plate oscillating heat pipe (RFP-OHP) heat spreader is investigated to study the effect of central heating on the heat transport capability in an OHP. The investigated OHP has dimensions of 100 mm × 100 mm × 2.5 mm with central heating using a 30 mm × 30 mm heater. Experimental results show that when heat is added to the center section of one side of the radial flat-plate OHP, and when heat is removed from the whole surface of another side of the heat pipe, the startup power for the oscillating motion increases. In addition, the spacer effect on the heat transport capability including the startup is investigated experimentally. The spacer added between the cooling block and OHP could lower the startup power for oscillatory motion. When compared to a copper slab of the same dimensions in the same test configuration, the temperature difference for the OHP with and without the additional copper spacer was reduced by a maximum of 46% and 25%, respectively, at a power input of 525 W and a heat flux of 58 W/cm2.

An Experimental Investigation of Heat Transport Capability in a Nanofluid Oscillating Heat Pipe

2006 ◽  
Vol 128 (11) ◽  
pp. 1213-1216 ◽  
Author(s):  
H. B. Ma ◽  
C. Wilson ◽  
Q. Yu ◽  
K. Park ◽  
U. S. Choi ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Heat Pipe ◽  
Heat Transport ◽  
Working Fluid ◽  
New Approach ◽  
Oscillating Heat Pipe ◽  
Diamond Nanoparticles ◽  
Hplc Grade Water ◽  
Oscillating Motion ◽  
Heat Transport Capability

An experimental investigation of a nanofluid oscillating heat pipe (OHP) was conducted to determine the nanofluid effect on the heat transport capability in an OHP. The nanofluid consisted of HPLC grade water and 1.0vol% diamond nanoparticles of 5-50nm. These diamond nanoparticles settle down in the motionless base fluid. However, the oscillating motion of the OHP suspends the diamond nanoparticles in the working fluid. Experimental results show that the heat transport capability of the OHP significantly increased when it was charged with the nanofluid at a filling ratio of 50%. It was found that the heat transport capability of the OHP depends on the operating temperature. The investigated OHP could reach a thermal resistance of 0.03°C∕W at a heat input of 336W. The nanofluid OHP investigated here provides a new approach in designing a highly efficient next generation of heat pipe cooling devices.

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