Heat transfer performance of water jet cooled mirror and its application in high power chemical lasers

2012 ◽  
Vol 24 (1) ◽  
pp. 51-55
Author(s):  
李斌 Li Bin ◽  
李兰 Li Lan ◽  
焦路光 Jiao Luguang ◽  
刘亮 Liu Liang ◽  
周琼 Zhou Qiong ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Power ◽  
Heat Transfer Performance ◽  
Water Jet ◽  
Transfer Performance

Heat Transfer Performance of an Air-Assisted Impinging Water Jet Under a Fixed Pumping Power Constraint

2013 ◽  
Author(s):  
Daniel Trainer ◽  
Sung Jin Kim
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Heat Transfer Performance ◽  
Plug Flow ◽  
Water Jet ◽  
Air Injection ◽  
Transfer Performance ◽  
Pumping Power ◽  
Two Phase ◽  
Impingement Point

Air injection into a liquid impinging jet has been shown to be a method of improving non-phase change heat transfer rates by up to twice the normal amount. Previous work has shown that there exists an optimal operating point in terms of the volumetric fraction of air injection when the pumping power is held constant because of an optimal two-phase flow pattern. However, previous work focused on heat transfer from the impingement point only, and neglected performance at other points. The present work studies the local heat transfer performance of an air-assisted water jet, at the impingement point and at positions moving radially outward, under constant pumping power conditions. The area-averaged heat transfer is also considered. Heat transfer at the stagnation point is shown to be optimized between β = 0.1∼0.2, where a bubbly flow pattern exists. Nuavg(r/D ≤ 1) is optimized when the flow pattern was plug-flow and off-center peaks in Nur exist. Nuavg(r/D > 1) is optimized when the water is accelerated by the injected air, but splattering is avoided. Flow patterns have no direct effect outside the impingement region.

scholarly journals Numerical Simulation, Machining and Testing of a Phase Change Heat Sink for High Power LEDs

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2193 ◽  
Author(s):  
Jianhua Xiang ◽  
Haoxing Zheng ◽  
Yipin Wang ◽  
Chunliang Zhang ◽  
Chao Zhou ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Transfer Performance ◽  
Machining Process ◽  
Normal Operation ◽  
Transfer Performance ◽  
New Type

Thermal management is crucial to guarantee the normal operation of light-emitting diodes (LEDs) Phase change heat sink is superior to traditional metal solid heat sink due to very small thermal resistance. In this study, a new type of phase change heat sink for high power LEDs is first designed. Then, the fabrication process of boiling structures at the evaporation surface of the phase change heat sink is discussed and analyzed. To make a comparison and deep discussion, the machining process is simulated through the FEM (finite element analysis) software, DEFORM-3D. Last but not least, heat transfer performance of the fabricated phase change heat sink is tested. Results have shown that the designed new type of phase change heat sink has superior heat transfer performance and is suitable for heat dissipation of high-power LEDs.

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