What factors contribute to the decrease in vapor velocity in heat pipes at high heat loads?
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The decrease in vapor velocity in heat pipes at high heat loads can be attributed to several factors. Enhanced wettability of the capillary wick can increase capillary pressure and suppress bubble perturbations, reducing the liquid supply velocity by over 70% . Additionally, during the start-up transient phase, multiple shock reflections in the evaporation region can cause reverse flows and circulations, leading to a significant increase in local pressure and pressure drops along the heat pipe . Furthermore, the use of nanofluids in heat pipes can result in improved thermal performance due to nano-coating effects, localized high vapor pressure, reduced contact angle, and enhanced boiling limits, impacting vapor velocity fluctuations . These combined factors influence the vapor velocity in heat pipes under high thermal loads.
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| Papers (5) | Insight |
|---|---|
| At high heat loads in heat pipes, factors like buoyancy effects and changes in thermophysical properties can contribute to the decrease in vapor velocity. | |
10 Citations | Factors contributing to decreased vapor velocity in heat pipes at high heat loads include intermittent accelerated flow, nano-coating of nanoparticles on the mesh, and reduction of contact angle. |
| Factors contributing to decreased vapor velocity in heat pipes at high heat loads include vapor jetting from bubble bursting, increased capillary pressure with enhanced wettability, and reduced liquid side pressure with higher inclination angles. | |
| Multiple shock reflections at high heat flux cause reverse flow in evaporation and circulations in the adiabatic region, leading to a significant increase in local pressure and pressure drop along the heat pipe. | |
| The presence of separate chambers for vapor-phase and liquid-phase working fluids in the heat pipe structure reduces impedance against vapor, enhancing heat transfer efficiency at high heat loads. |
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