Numerical study of bubbles rising and merging during convective boiling in micro-channels
2016 (English)In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 99, 1141-1151 p.Article in journal, Editorial material (Refereed) Published
A three dimensional numerical study on bubble growth and merger in a micro-channel with diameter of 0.64 mm has been conducted. The working fluid is R134a and the wall material is steel. The inlet Reynolds number is set at 549 in order to keep the flow in laminar regime. Two different heat fluxes () are supplied to the wall to heat up the fluid. The coupled level set and volume of fluid (CLSVOF) method is used to capture the distorted two-phase interface. An evaporation model is also implemented through UDF (User defined function). The combination of these two methods has successfully eliminated spurious velocities which is a common problem in two phase flow simulation. The boiling and merger processes are well-predicted by the simulation. It is found that the whole process can be divided into three sub-stages: sliding, merger, and post-merger. The dynamics and heat transfer are found to be different in these stages. The evaporation rate is much higher in the first two stages due to the thermal boundary layer effects.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 99, 1141-1151 p.
boiling, CFD, bubbles, numerical, microchannels
Research subject Engineering Mechanics
IdentifiersURN: urn:nbn:se:kth:diva-185700DOI: 10.1016/j.applthermaleng.2016.01.116ScopusID: 2-s2.0-84958964200OAI: oai:DiVA.org:kth-185700DiVA: diva2:922942
FunderSwedish Energy Agency
QC 201604292016-04-252016-04-252016-05-10Bibliographically approved