Effect of Gravity on Electrohydrodynamic Conduction Driven Liquid Film Flow Boiling

2016 ◽  
Vol 30 (2) ◽  
pp. 429-437 ◽  
Author(s):  
Viral K. Patel ◽  
Jamal Seyed-Yagoobi ◽  
Franklin Robinson ◽  
Jeffrey R. Didion
Keyword(s):  
Liquid Film ◽  
Film Flow ◽  
Flow Boiling ◽  
Liquid Film Flow

scholarly journals Combined Dielectrophoretic and Electrohydrodynamic Conduction Pumping for Enhancement of Liquid Film Flow Boiling

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Viral K. Patel ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Heat Transfer ◽  
Liquid Film ◽  
Film Flow ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Transport Systems ◽  
Heater Surface ◽  
Force Magnitude ◽  
Boiling Heat Transfer Coefficient ◽  
Liquid Film Flow

This paper extends previous liquid film flow boiling studies by including the effect of an additional electrohydrodynamic (EHD) force, namely, the dielectrophoretic (DEP) force. Rather than using only EHD conduction pumping of the liquid film to electro-wet the heater surface, a localized nonuniform electric field above the heater surface is established to generate a DEP force for improved vapor bubble extraction during the nucleate boiling regime. The effects of liquid film height and applied potential are studied as a function of heater superheat and heat flux. A brief analytical study is also used to estimate the expected DEP force magnitude to explain the results. All of the above studies are also used to quantify the enhancement in heat transfer that can be achieved when heat transport systems are driven or augmented by these two EHD mechanisms. The results show remarkable enhancement of up to 1217% in boiling heat transfer coefficient at a given superheat when both mechanisms are used simultaneously. The experimental data are important for applications in thermal management in terrestrial and space conditions.

Investigation of Gravity Effects on Electrically Driven Liquid Film Flow Boiling: A Micro-Gravity Flight Campaign in Preparation of ISS Experiment

2021 ◽  
Author(s):  
Alexander J. Castaneda ◽  
Nathaniel O'connor ◽  
Jamal S. Yagoobi ◽  
Jeffrey R. Didion ◽  
Mario S. Martins
Keyword(s):  
Liquid Film ◽  
Film Flow ◽  
Flow Boiling ◽  
Gravity Effects ◽  
Liquid Film Flow ◽  
Micro Gravity

Electrohydrodynamic Conduction Pumping-Driven Liquid Film Flow Boiling on Bare and Nanofiber-Enhanced Surfaces

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Viral K. Patel ◽  
Jamal Seyed-Yagoobi ◽  
Suman Sinha-Ray ◽  
Sumit Sinha-Ray ◽  
Alexander Yarin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Liquid Film ◽  
Boiling Heat Transfer ◽  
Film Flow ◽  
Flow Boiling ◽  
Copper Substrate ◽  
Polymer Nanofiber ◽  
Liquid Film Flow ◽  
Bare Surface

Liquid film flow boiling heat transfer driven by electrohydrodynamic (EHD) conduction pumping is experimentally studied on a surface with a novel metal-plated nanofiber-mat coating. The nanotextured surface is formed on a copper substrate covered by an electrospun polymer nanofiber mat, which is copper-plated as a postprocess. The mat has a thickness of about 30 μm and is immersed in saturated HCFC-123. The objective is to study electrowetting of the copper-plated nanofiber-enhanced surface via EHD conduction pumping mechanism for the entire liquid film flow boiling regime leading up to critical heat flux (CHF), and compare it to the bare surface without EHD-driven flow. The results show that with the combination of these two techniques, for a given superheat value, enhancement in heat flux and boiling heat transfer coefficient is as high as 555% compared to the bare surface. The results are quite promising for thermal management applications.

Investigation of Gravity Effects on Electrically Driven Liquid Film Flow Boiling: A Micro-Gravity Flight Campaign in Preparation of ISS Experiment

2020 ◽  
Author(s):  
Alexander J. Castaneda ◽  
Nathaniel J. O’Connor ◽  
Jamal Yagoobi
Keyword(s):  
Liquid Film ◽  
Heat Transport ◽  
Film Flow ◽  
Flow Boiling ◽  
Parabolic Flight ◽  
Space Station ◽  
Two Phase ◽  
Ability To Act ◽  
Liquid Film Flow ◽  
Micro Gravity

Abstract The ongoing development of modern electronic systems leads to smaller, more powerful devices that are expected to operate in complex environments. Due to this, advanced thermal management technologies are required to meet the growing demand, especially in space where two-phase thermal systems are limited by the absence of gravity. Electrohydrodynamic (EHD) and dielectrophoretic (DEP) forces can be used to sustain stable liquid film boiling in micro-gravity, which is otherwise impractical due to the lack of a required buoyancy force to initiate bubble departure. EHD and DEP are phenomena that are represented by the interaction between electric fields and fluid flow. The DEP force especially is characterized by the unique ability to act on liquid/vapor interfaces due to a high gradient of electrical permittivity, allowing for two phase operation. This study investigates the effect of EHD conduction pumping coupled with DEP vapor extraction on liquid film flow boiling during a microgravity parabolic flight, and it characterizes the future two-phase microgravity heat transport technology prior to testing on the International Space Station (ISS). The results of this study show that EHD and DEP raise critical heat flux, lower heater surface temperature, and successfully sustain boiling in micro-gravity all at the cost of low power consumption. Additionally, the heat transfer data captured in terrestrial, microgravity, and 1.8 g conditions compare well, indicating that this technology can provide thermal enhancement independent of gravity. This study paves the way for future implementation of EHD-driven two-phase heat transport devices into space and aeronautical electronics applications.

Combined Electrohydrodynamic Conduction Pumping and Dielectrophoresis for Enhancement of Liquid Film Flow Boiling

2015 ◽  
Author(s):  
Viral K. Patel ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Liquid Film ◽  
Film Flow ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Transport Systems ◽  
Heater Surface ◽  
Dielectrophoretic Force ◽  
Liquid Film Flow

The research in this paper extends previous liquid film flow boiling studies by including the effect of an additional electrohydrodynamic (EHD) force, namely the dielectrophoretic (DEP) force. Rather than using only EHD conduction pumping of the liquid film to electro-wet the heater surface, a localized non-uniform electric field above the heater surface is also used to generate a dielectrophoretic force for improved vapor bubble extraction during the nucleate boiling regime. The effect of liquid film height and applied potential are studied as a function of heater superheat and heat flux. The study considers the sole and combined effect of DEP with EHD conduction pumping. A brief analytical study is also used to estimate the expected dielectrophoretic force magnitude and explain the results. All of the above studies are also used to quantify the enhancement in heat transfer that can be achieved when heat transport systems are driven or augmented by these electrohydrodynamic phenomena. The results show remarkable enhancement of up to 1217% in heat flux and boiling heat transfer coefficient for a given superheat when both mechanisms are used simultaneously. The experimental data are important for applications in thermal management in terrestrial and micro-gravity conditions.

Sign in / Sign up

Export Citation Format

Share Document