The Behavior of Turbulent Heat Transfer Deterioration in Supercritical Hydrocarbon Fuel Flow Considering Thermal Resistance Distribution

Two-dimensional turbulent heat transfer between a series of parallel plates with surface mounted discrete block heat sources was studied numerically. The computational domain was subjected to periodic conditions in the streamwise direction and repeated conditions in the cross-stream direction (Double Cyclic). The second source term was included in the energy equation to facilitate the correct prediction of a periodically fully developed temperature field. These channels resemble cooling passages in electronic equipment. The k–ε model was used for turbulent closure and calculations were made for a wide range of independent parameters (Re, Ks/Kf, s/w, d/w, and h/w). The governing equations were solved by using a finite volume technique. The numerical procedure and implementation of the k–ε model was validated by comparing numerical predictions with published experimental data (Wirtz and Chen, 1991; Sparrow et al., 1982) for a single channel with several surface mounted blocks. Computations were performed for a wide range of Reynolds numbers (5 × 104–4 × 105) and geometric parameters and for Pr = 0.7. Substrate conduction was found to reduce the block temperature by redistributing the heat flux and to reduce the overall thermal resistance of the module. It was also found that the increase in the Reynolds number decreased the thermal resistance. The study showed that the substrate conduction can be an important parameter in the design and analysis of cooling channels of electronic equipment. Finally, correlations for the friction factor (f) and average thermal resistance (R) in terms of independent parameters were developed.

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Turbulent heat transfer analysis in supercritical hydrogen fuel flow considering thermal stratification

Numerical Heat Transfer Part A Applications ◽

10.1080/10407782.2020.1746566 ◽

2020 ◽

Vol 77 (10) ◽

pp. 913-929 ◽

Cited By ~ 1

Author(s):

Pengyong Xie ◽

Xiaobing Zhang

Keyword(s):

Heat Transfer ◽

Thermal Stratification ◽

Heat Transfer Analysis ◽

Turbulent Heat Transfer ◽

Turbulent Heat ◽

Hydrogen Fuel ◽

Fuel Flow

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A study of turbulent heat transfer in convergent-divergent shaped microchannel with ribs and cavities using CFD

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.1.2020.12.0497 ◽

2020 ◽

Vol 14 (1) ◽

pp. 6344-6361

Author(s):

Pankaj Srivastava ◽

Anupam Dewan

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Thermal Resistance ◽

Average Nusselt Number ◽

Three Dimensional ◽

Fluid Mixing ◽

Turbulent Heat Transfer ◽

Turbulent Heat ◽

Rectangular Microchannel ◽

Better Than

This paper presents the effects of microchannel shape with ribs and cavities on turbulent heat transfer. Three-dimensional conjugate heat transfer using the SST k-ω turbulence model has been investigated for four different microchannels, namely, rectangular, rectangular with ribs and cavities, convergent-divergent (CD) and convergent-divergent with Ribs and Cavities (CD-RC). The flow field, pressure and temperature distributions and friction factor are analyzed, and thermal resistance and average Nusselt number are compared. The thermal performance of the CD-RC microchannel is found to be better than that of other microchannels considered in terms of an average Nusselt number increased from 16% to 40%. Heat transfer increases due to a strong fluid mixing and periodic interruption of boundary-layer. It is observed that with an increase in Reynolds number (Re), the thermal resitance drops rapidly. The thermal resistance of the CD-RC microchannel is decreased by 30% than that of the rectangular microchannel for Re ranging from 2500 to 7000. However, such design of microchannel loses its heat transfer effectiveness due to a high pumping power at high values of Re.

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