Noninvasive temperature measurements of RLIF and nPIT in DI water flow microchannels

• Published in: Applied thermal engineering 2017-05, Vol.117, p.30-38
• Main Authors: Hsieh, Shou-Shing, Li, Shih-Yang, Hsieh, Yu-Cheng
• Format: Article
• Language: English
• Subjects: Fluid dynamics; Fluid flow; Fluorescence; Heat conductivity; Heat transfer; Heat transfer coefficients; Microchannel; Microchannels; Near-wall; nPIT; Nusselt number; RLIF; Studies; Temperature distribution; Thermocouples; Wall temperature; Water flow
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2017.01.117

•The thermal slip and temperature jump still seem to be observable, but not clearly.•It is found at Re=2 that the present flow can be thermally fully developed.•The local Nusselt number results are still a little higher than previous studies. Experiments were performed herein to examine the near-wall water flow/thermal characteristics and bulk flow behavior in a 20mm long microchannel with a height of 45μm (thermal) and a width of 200μm, through the noninvasive optical measuring techniques of nPIT and RLIF. The corresponding streamwise wall temperature distribution (45μm channel) was measured. It was found that at Re=2, the flow can be fully developed thermally. In addition, both the local heat transfer coefficient and the corresponding Nusselt number were obtained via the RLIF and traditional thermocouple measurements. When compared to the results of previous studies our results are in good agreement.