Browsing by Author "Chu, C. M."

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Heat transfer correlations of forced convective boiling for pure refrigerants in micro-fin tubes
(2011-04-01)
Chiou, C. B.
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Lu, D. C.
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Chen, C. C.
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Chu, C. M.
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機械工程學系
The evaporation heat transfer coefficient of pure refrigerants R-22 and R-124 in micro-fin tubes were measured at the reduced pressure of 0.15, the mass flux from 100 to 400 kg/m(2) s, the flow quality from 0.1 to 0.9, and the heat flux from 5 to 20 kW/m(2). The evaporation heat transfer coefficient of pure refrigerant in micro-fin tube is 1.5-3.0 times higher than that of smooth tube. In this article, the single phase forced convection heat transfer coefficient of micro-fin tube is introduced to predict the evaporation heat transfer coefficient of pure refrigerant in micro-fin tubes. The present correlations provide reasonable agreement with the experimental data. The prediction values mostly fall within +/- 30%. (C) 2010 Elsevier Ltd. All rights reserved.
Hybrid Dendrimer/Semiconductor Nanostructures with Efficient Energy Transfer via Optical Waveguiding
(2015-03-05)
Lin, T. N.
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Huang, J. C.
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Shen, J. L.
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Chu, C. M.
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Yeh, J. M.
In this study, we demonstrated a nonradiative energy transfer between InGaN quantum wells (QWs) and polyamidoamine (PAMAM) dendrimers through optical waveguiding by detecting a reduction in the photoluminescence lifetime. The maximum energy transfer efficiency of this system is similar to 72%, which is promising for sensor applications. The energy transfer efficiency depends on the distance between the InGaN QWs and PAMAM dendrimers by a factor of 1/d(2), revealing layer-to-layer dipole interactions. Upon increasing the generation of PAMAM dendrimers, the transfer energy efficiency increases exponentially, which can be explained by the increased surface coverage for the higher generation.