Subcooled two-phase flow boiling in a microchannel heat sink: comparison of conventional numerical models
Authors
Abstract:
Subcooled flow boiling in multi-microchannels can be used as an efficient thermal management approach in compact electrical devices. Highly subcooled flow boiling of HFE 7100 is studied in two microchannel heat sinks to choose a proper numerical model for simulating boiling flows in microchannels. Results of five different numerical models, including Volume of Fluid (VOF), Eulerian boiling, Eulerian Lee, Eulerian thermal phase change, and mixture models, were compared with experimental data. ANSYS Fluent was used as the numerical tool to solve three-dimensional governing equations. Results were obtained in the steady-state condition of the transient solution. The average wall temperature reached a steady state in all models except in Eulerian boiling and mixture models. It was found that Eulerian thermal phase change and VOF models predicted microchannel’s bottom wall average temperature with less than 2% error. VOF model predicted flow boiling regime as it was reported in the experimental research and boiling curves. Velocity distribution over microchannel height was investigated, and it was observed that after the onset of nucleate boiling, the velocity profile becomes asymmetrical. Also, in the two-phase regions, each phase had a different velocity magnitude and distribution. Based on flow regime and temperature results, which were compared with experimental data, VOF model was recommended as the best model to simulate flow boiling in microchannels at the working conditions of this research. Furthermore, subcooled flow boiling’s capability to be used in thermal management systems was proved while observing temperature distribution over computational domain.
similar resources
Effects of Dissolved Air on Subcooled Flow Boiling of a Dielectric Coolant in a Microchannel Heat Sink
The effects of dissolved air in the dielectric liquid FC-77 on flow boiling in a microchan-nel heat sink containing ten parallel channels, each 500 m wide and 2.5 mm deep, were experimentally investigated. Experiments were conducted before and after degas-sing, at three flow rates in the range of 30– 50 ml/ min. The dissolved air resulted in a significant reduction in wall temperature at which...
full textTwo Phase Flow Simulation for Subcooled Nucleat Boiling Heat Transfer Calculation in Water Jacket of Diesel Engine
Basic understanding of the process of coolant heat transfer inside an engine is an indispensable prerequisite to devise an infallible cooling strategy. Coolant flow and its heat transfer affect the cooling efficiency, thermal load of heated components, and thermal efficiency of a diesel engine. An efficient approach to studying cooling system for diesel engine is a 3D computational fluid dynami...
full textExperimental Investigation and Theoretical Model for Subcooled Flow Boiling Pressure Drop in Microchannel Heat Sinks
This study examines the pressure drop characteristics of subcooled two-phase microchannel heat sinks. A new model is proposed, which depicts the subcooled flow as consisting of a homogeneous two-phase flow layer near the heated walls of the microchannel and a second subcooled bulk liquid layer. This model is intended for conditions where subcooled flow boiling persists along the entire microcha...
full textDevelopment of a Numerical Model for Subcooled Boiling Flow
Population balance equations combined with a threedimensional two-fluid model are employed to predict bubbly flows with the presence of heat and mass transfer processes. Subcooled boiling flow belongs to this specific category of bubbly flows is considered. The MUSIG (MUltiple-SIze-Group) model implemented in CFX4.4 is further developed to account for the wall nucleation and condensation in the...
full textNumerical investigating the gas slip flow in the microchannel heat sink using different materials
In this work, slip flow of helium gas has been studied in a three dimensional rectangular microchannel heat sink with 11 microchannel and 10 rectangular fins. Helium gas flow is considered ideal and incompressible. The finite volume method with using coupled algorithm is employed to carry out the computation. To validate the present work, comparison with numerical and experimental studies is do...
full textMy Resources
Journal title
volume 51 issue 1
pages 37- 45
publication date 2020-06-01
By following a journal you will be notified via email when a new issue of this journal is published.
Hosted on Doprax cloud platform doprax.com
copyright © 2015-2023