Guillermo AguilarProfessor Emeritus and AdjunctMechanical Engineering Dept gaguilar@ucr.edu(951) 827-7717
Collaborative Research: Understanding Laser-Assisted Surface Cooling Enhancement (LASCE)
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AWARD NUMBER
006813-002
FUND NUMBER
21261
STATUS
Closed
AWARD TYPE
3-Grant
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AWARD EXECUTION DATE
6/6/2014
BEGIN DATE
6/1/2014
END DATE
6/30/2017
AWARD AMOUNT
$225,346
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Sponsor Information
SPONSOR AWARD NUMBER
SPONSOR
SPONSOR TYPE
FUNCTION
Organized Research
PROGRAM NAME
Proposal Information
PROPOSAL NUMBER
14040315
PROPOSAL TYPE
New
ACTIVITY TYPE
Basic Research
PI Information
PI
Aguilar, Guillermo
PI TITLE
Other
PI DEPTARTMENT
Mechanical Engineering
PI COLLEGE/SCHOOL
Bourns College of Engineering
CO PIs
Project Information
ABSTRACT
CBET-1403508/1402587
Aguilar/Trujillo
This grant provides funding for studying and developing a non-intrusive method to enhance local heat transfer between a target surface and a cooling fluid. The approach takes advantage of thermocavitation bubbles, which are formed when continuous wave (CW) laser light is properly focused within highly-absorbing liquid thin films. These bubbles form and collapse within microseconds, vigorously agitating the liquid and enhancing heat transfer. This phenomenon is called Laser-Assisted Surface Cooling Enhancement (LASCE). The PI's preliminary estimates show that heat transfer enhancement is as great as that of phase change (evaporation/boiling), which is the current upper limit to liquid-based cooling systems. LASCE may also match or exceed the performance obtained using micro-modified structures, but without implementing any type of surface modification. Also, CW lasers are often less complex lasing media, cheaper and simpler than pulse lasers, and can control the frequency of bubble formation simply by modulating their output power. The potential impact of this project, therefore, is in novel ways of controlling surface heat. This has implications for systems ranging from laser surgery to combustion engine devices.
This study encompasses collaborative experimental and computational research between University of California-Riverside and University of Wisconsin-Madison aimed at studying and quantifying the: 1) balance between the heat input to induce thermal cavitation and the cooling produced by enhanced convection; 2) sensitivity of the resulting fluid flow to the operating parameters of the laser and; 3) physics of interaction between multiple cavitation events and its effect on enhanced convective cooling. Based on highly accurate numerical simulations and detailed measurement techniques, a thorough examination of the physics underpinning the most desirable heat transfer conditions will be sought, which is essential in optimizing the operation of LASCE. This will be followed by an equally important objective, which aims to explore LACSE's suitability for applications where surface modification is impossible, such as skin (scalp) cooling during laser therapy across a novel transparent cranial implant ("Window to the Brain") developed at UCR. The success of this project will open the door to many transformative applications of optical thermocavitation aimed at low-temperature combustion strategies for mitigating the levels of NOx and particulate matter emissions to improve engine efficiency as well as transdermal drug delivery for diverse biomedical applications.(Abstract from NSF)
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