Measurement of flow maldistribution induced by the Ledinegg instability during boiling in thermally isolated parallel microchannels
نویسندگان
چکیده
• Maldistribution of flow in parallel boiling microchannels, induced by the Ledinegg instability, is directly measured The severity maldistribution and temperature difference between channels grows with increasing power Under most extreme conditions recorded, as much 96.5% total rate directed through one channel Transient data are presented to illustrate hydrodynamic excursion resulting from instability Flow a network heated prone instabilities that can cause uneven distribution, thereby degrading heat transfer performance system limiting predictability. This study experimentally investigates two microchannels arises due instability. uniformly thermally isolated each other, such both subjected same input regardless distribution. hydrodynamically connected deionized water delivered at constant shared channels. Direct measurements rate, wall temperature, pressure drop individual performed simultaneously visualization. At low levels, when remain single-phase liquid regime, evenly distributed they attain temperature. As increased, incipience triggers which causes become maldistributed induces maldistribution, well channels, power. In condition this study, operating while starved receives just 3.5% flow. quantitative account non-uniformity here provides mechanistic understanding effects instability-induced on characteristics microchannels.
منابع مشابه
Ledinegg instability in microchannels
The static Ledinegg instability in horizontal microchannels under different flow conditions and fluids pertinent to electronics cooling was studied experimentally and numerically. Two fluids, water at sub-atmospheric pressures and refrigerant HFE-7100, were examined for a range of heat fluxes, mass fluxes, and channel hydraulic diameters. Numerical predictions from the developed pressure gradie...
متن کاملNucleation characteristics and stability considerations during flow boiling in microchannels
Flow boiling in microchannels and minichannels has received considerable attention in the past decade. The interest stems from the possibility of achieving the extremely high heat fluxes, over 1 kW/cm, needed for future generation electronics cooling application. The attention has been focused on obtaining experimental heat transfer and pressure drop data, but the fundamental aspects of nucleat...
متن کاملHeat Transfer Mechanisms During Flow Boiling in Microchannels
The forces due to surface tension and momentum change during evaporation, in conjunction with the forces due to viscous shear and inertia, govern the two-phase flow patterns and the heat transfer characteristics during flow boiling in microchannels. These forces are analyzed in this paper, and two new nondimensional groups, K1 and K2 , relevant to flow boiling phenomenon are derived. These grou...
متن کاملDirect Simulation Based Model-Predictive Control of Flow Maldistribution in Parallel Microchannels
Flow maldistribution, resulting from bubbles or other particulate matter, can lead to drastic performance degradation in devices that employ parallel microchannels for heat transfer. In this work, direct numerical simulations of fluid flow through a prescribed parallel microchannel geometry are performed and coupled with active control of actuated microvalves to effectively identify and reduce ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal of Multiphase Flow
سال: 2021
ISSN: ['1879-3533', '0301-9322']
DOI: https://doi.org/10.1016/j.ijmultiphaseflow.2021.103644