Performance Evaluation Criterion at Equal Pumping Power for Enhanced Performance Heat Transfer Surfaces

Karwa, Rajendra; Sharma, Chandresh; Karwa, Nitin

doi:10.1155/2013/370823

Cited by 56 publications

(13 citation statements)

References 40 publications

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“…The thermal enhancement factor ( ƞ ) is adopted to access the enhanced heat transfer surfaces in heat exchange design. According to Webb [ 30 ] and Karwa [ 31 ], the performance enhancement factor is defined as the ratio of the heat transfer coefficient of the microchannel with cavities to the simple straight microchannel under equal pumping power

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Section: Methodsmentioning

confidence: 99%

Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Huang

et al. 2020

Micromachines

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Due to the large surface-area-to-volume ratio, microchannel heat exchangers have a higher heat transfer rate compared with traditional scale heat exchangers. In this study, the optimum microchannel cavity with high heat transfer and low flow resistance is designed to further improve microchannel exchangers’ thermal performance. A three-dimensional laminar flow model, consisting of Navier–Stokes equations and an energy conservation equation is solved and the conjugate heat transfer between the silicon basement and deionized water is taken into consideration. The impact of the shape, aspect ratio, size and spacing of the cavity on the thermal performance of microchannel exchangers are numerically investigated, respectively. The results indicated that the cavity on the sidewall can enhance heat transfer and reduce flow resistance simultaneously, and cavities with a relatively small expansion angle and streamlined edge could enhance thermal performance the most. Based on the conclusions, a new cavity shape is proposed, and the simulation results verify its excellent thermal performance as expected. Furthermore, investigation is performed to figure out the optimum design of the new cavity and the optimal geometric parameters of the cavity under different flow conditions have been obtained in principle for microchannel exchangers’ design.

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…”

Section: Methodsmentioning

confidence: 99%

Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Huang

et al. 2020

Micromachines

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“…The pump power of an MAHS for steady flow can be defined as: (17) where the inlet area A in = φ 2 π 4 and φ is the inlet diameter, which was set to be 330 µm in the present work. The average Nusselt number with an identical pump power was suggested to be a good option to evaluate the thermal performance of an MAHS [34] because the pump power, a very common index in practical engineering, represents the flow resistance, and the Nusselt number (or thermal resistance) represents heat transfer capability. In fact, the Nusselt number with an identical pump power can be used to replace the Nu/ f 1/3 [12,18] to evaluate the thermal performance of the heat sink.…”

Section: Parameters For Evaluating the Thermal Performancementioning

confidence: 99%

Parametric Investigation on a Micro-Array Heat Sink with Staggered Trapezoidal Bumps

et al. 2019

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More efficient heat sinks are required due to the rapid increase of power density in microelectronic devices. In this study, a micro-array heat sink with stagger trapezoidal bumps was designed. Numerical simulations for the flow and heat transfer under various conditions were carried out to help us to fully understand the mechanisms of the heat transfer enhancement in such a heat sink. The effects of the structure of the heat sink, parameters of the bumps, and volume fraction of the nanofluid on the performance of heat sink were studied. The results show us that the bumps in the heat sink can result in chaotic convection, interrupting the thermal boundary layer and increasing the cooling area, subsequently improving the heat transfer performance. Furthermore, parametric investigations for trapezoidal bumps were conducted to obtain preferential values for parameters, such as the bump width, fore rake angle of the bump, bump height, and bump pitch.

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“…A suitable index to measure the heat transfer enhancement which is named the Performance Evaluation Criterion (PEC) is needed for the comprehensive consideration of heat convective and pressure loss along the stream. Hence, PEC can be defined as [ 40 ]:

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Section: Computational Proceduresmentioning

confidence: 99%

Analysis and Optimization of Trapezoidal Grooved Microchannel Heat Sink Using Nanofluids in a Micro Solar Cell

Wang

Wen

Wang

et al. 2017

Entropy

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Abstract:It is necessary to control the temperature of solar cells for enhancing efficiency with increasing concentrations of multiple photovoltaic systems. A heterogeneous two-phase model was established after considering the interacting between temperature, viscosity, the flow of nanofluid, and the motion of nanoparticles in the nanofluid, in order to study the microchannel heat sink (MCHS) using Al 2 O 3 -water nanofluid as coolant in the photovoltaic system. Numerical simulations were carried out to investigate the thermal performance of MCHS with a series of trapezoidal grooves. The numerical results showed us that, (1) better thermal performance of MCSH using nanofluid can be achieved from a heterogeneous two-phase model than that from single-phase model; (2) The effects of flow field, volume fraction, nanoparticle size on the heat transfer enhancement in MCHS were interpreted by a non-dimensional parameter N BT (i.e., ratio of Brownian diffusion and thermophoretic diffusion). In addition, the geometrical parameters of MCHS and the physical parameters of the nanofluid were optimized. This can provide a sound foundation for the design of MCHS.

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Performance Evaluation Criterion at Equal Pumping Power for Enhanced Performance Heat Transfer Surfaces

Cited by 56 publications

References 40 publications

Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Parametric Investigation on a Micro-Array Heat Sink with Staggered Trapezoidal Bumps

Analysis and Optimization of Trapezoidal Grooved Microchannel Heat Sink Using Nanofluids in a Micro Solar Cell

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