Log In   |   Sign up

New User Registration

Article / Abstract Submission
Register here
Register
Press Release Submission
Register here
Register
coolingZONE Supplier
Register here
Register

Existing User


            Forgot your password
John O | December 2016

Syracuse researchers improve heat transfer in boiling


syracuse university researchers have discovered a method for early evaporation of the microlayer at the base of a bubble in boiling water that enhances the critical heat flux (chf) and improves the efficiency of boiling heat transfer, according to a report from the school.

 

syracuse_600

researchers increased critical heat flux through boiling heat transfer. (wikimedia commons)

 

the conventional method for enhancing chf was to modify the surface where heat transfer is taking place. researchers did this by increasing the nucleation site density, surface wettability or wicking effect, separating pathways for liquid and vapor flows, or increasing the surface roughness.

 

the team of researchers at syracuse created microridges on the surface of the think liquid film at the base of a bubble, which causes the bulk of the liquid to evaporate quicker. early evaporation increases the bubble growth rate, the departure frequency and chf.

 

according to the researchers, there is approximately a 120 percent enhancement in chf with only an 18 percent increase in surface area. the article stated that this is “the highest such enhancement reported in literature.”

 

the research was reported in langmuir. the abstract from the report stated:

 

“for over five decades, an enhancement in pool boiling heat transfer has been achieved by altering the surface wetting, wickability, roughness, nucleation site density, and providing separate liquid/vapor pathways. in this work, a new enhancement mechanism based on the early evaporation of the microlayer is discovered and validated.

 

“the microlayer is a thin liquid film present at the base of a vapor bubble. the presence of microridges on the silicon dioxide surface partitions the microlayer and disconnects it from the bulk liquid, causing it to evaporate sooner, thus leading to increase in the bubble growth rate, heat transfer, departure frequency, and critical heat flux (chf).

 

“compared to a plain surface, an ∼120% enhancement in chf is obtained with only an ∼18% increase in surface area. a chf enhancement map is developed on the basis of the ridge height and spacing, resulting in three regions of full, partial, and no enhancement. the new mechanism is validated by comparing the growth rate of a laser-created vapor bubble on a ridge-structured surface and a plain surface, and the corresponding prediction of the chf enhancement is found to be in good agreement with the experimental boiling data.

 

“this discovery opens up a new field of chf enhancement and can potentially be coupled with existing techniques to further push the limits of boiling heat transfer.”

 

there is hope that this new discovery could lead to the next generation of thermal management of electronics using nanostructures that can produce the ideal heat transfer rate through boiling.

Choose category and click GO to search for thermal solutions

 
 

Subscribe to Qpedia

a subscription to qpedia monthly thermal magazine from the media partner advanced thermal solutions, inc. (ats)  will give you the most comprehensive and up-to-date source of information about the thermal management of electronics

subscribe

Submit Article

if you have a technical article, and would like it to be published on coolingzone
please send your article in word format to articles@coolingzone.com or upload it here

Subscribe to coolingZONE

Submit Press Release

if you have a press release and would like it to be published on coolingzone please upload your pr  here

Member Login

Supplier's Directory

Search coolingZONE's Supplier Directory
GO
become a coolingzone supplier

list your company in the coolingzone supplier directory

suppliers log in

Media Partner, Qpedia

qpedia_158_120






Heat Transfer Calculators