000214068 001__ 214068
000214068 005__ 20181203024057.0
000214068 0247_ $$2doi$$a10.1016/j.energy.2015.07.119
000214068 022__ $$a0360-5442
000214068 02470 $$2ISI$$a000364248100082
000214068 037__ $$aARTICLE
000214068 245__ $$aUnderstanding the self-sustained oscillating two-phase flow motion in a closed loop pulsating heat pipe
000214068 260__ $$aOxford$$bPergamon-Elsevier Science Ltd$$c2015
000214068 269__ $$a2015
000214068 300__ $$a11
000214068 336__ $$aJournal Articles
000214068 520__ $$aIn the framework of efficient thermal management schemes, pulsating heat pipes (PHPs) represent a breakthrough solution for passive on-chip two-phase flow cooling of micro-electronics. Unfortunately, the unique coupling of thermodynamics, hydrodynamics and heat transfer, responsible for the self-sustained pulsating two-phase flow in such devices, presents many challenges to the understanding of the underlying physical phenomena which have so far eluded accurate prediction. In this experimental study, the novel time-strip image processing technique was used to investigate the thermo-flow dynamics of a single-turn channel CLPHP (closed loop pulsating heat pipe) charged with R245fa and tested under different operating conditions. The resulting frequency data confirmed the effect of flow pattern, and thus operating conditions, on the oscillating behavior. Dominant frequencies from 1.2 Hz for the oscillating regime to 0.6 Hz for the unidirectional flow circulation regime were measured, whilst wide spectral bands were observed for the unstable circulation regime. In order to analytically assess the observed trends in the spectral behavior, a spring-mass-damper system model was developed for the two-phase flow motion. As well as showing that system stiffness and mass have an effect on the two-phase flow dynamics, further insights into the flow pattern transition mechanism were also gained. (C) 2015 Elsevier Ltd. All rights reserved.
000214068 6531_ $$aCLPHP (closed loop pulsating heat pipes)
000214068 6531_ $$aTime-strip technique
000214068 6531_ $$aTwo-phase flow oscillations
000214068 6531_ $$aTime-frequency analysis
000214068 6531_ $$aSpring-mass-damper system
000214068 700__ $$0246085$$aSpinato, Giulia$$g193460
000214068 700__ $$aBorhani, Navid
000214068 700__ $$0240577$$aThome, John R.$$g108776
000214068 773__ $$j90$$q889-899$$tEnergy
000214068 909C0 $$0252128$$pLTCM$$xU10312
000214068 909CO $$ooai:infoscience.tind.io:214068$$pSTI$$particle
000214068 917Z8 $$x206908
000214068 937__ $$aEPFL-ARTICLE-214068
000214068 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000214068 980__ $$aARTICLE