Active control of surface temperatures in microchannel flow boiling
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Authors
Vutha, Ashwin Kumar
Issue Date
2017-08
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Mechanical engineering
Alternative Title
Abstract
In this dissertation, a novel approach is presented to control surface temperatures and enhance heat transfer in microchannel flow boiling. Experiments were performed using a microdevice with resistance-temperature detectors (RTDs) as heating and sensing elements. The flow was visualized through a high-speed imaging system. A transverse jet in crossflow was used to control surface temperatures and to effectively suppress dryout, at nominal heat fluxes up to 14 W/cm². A setpoint-based feedback control mechanism was evaluated under conditions of steady and transient heating, and its performance was compared to the reference case without active control. Maximum surface-averaged heat transfer enhancements of 130% and 127% were obtained with active control for steady and unsteady heating respectively. Transient local temperature measurements were made and used to compute the corresponding heat transfer coefficients. Active control allowed the local surface temperatures to be maintained in the vicinity of the specified setpoint in most cases.
Description
August 2017
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY