Computational prediction of pressure drop and heat transfer with cryogen based nanofluids to be used in micro-heat exchangers

Dondapati, Raja Sekhar; Saini, Vishnu; Verma, K.N.; Usurumarti, Preeti Rao

doi:10.1016/j.ijmecsci.2017.06.012

Cited by 31 publications

(7 citation statements)

References 53 publications

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“…This is particularly useful for microchip cooling, which is extremely popular in computer engineering and a must have-piece of technology since the space is relatively constrained. Other microchannel and microtube applications include, but are not limited to: automobile, transportation and biomedical industries, as well as broader usages in refrigeration systems [39], micro-reactors [40], transformers [41], solar collectors [42] and many more [43].…”

Section: Microchannel Introductionmentioning

confidence: 99%

Heat Transfer Enhancement Using Passive Technique: Review

2021

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Preserving and saving energy have never been more important, thus the requirement for more effective and efficient heat exchangers has never been more important. However, in order to pave the way for the proposal of a truly efficient technique, there is a need to understand the shortcomings and strengths of various aspects of heat transfer techniques. This review aims to systematically identify these characteristics two of the most popular passive heat transfer techniques: nanofluids and helically coiled tubes. The review indicated that nanoparticles improve thermal conductivity of base fluid and that the nanoparticle size, as well as the concentrations of the nanoparticles plays a major role in the effectiveness of the nanofluids. Regarding the helically coiled tubes, it was discovered that the use of a coiled tube produces secondary flows, which ultimately improves the heat transfer enhancement. The third part of the review focused on microchannels and microtubes. This is mainly due to the growing need and requirement of smaller and more compact thermal cooling systems. Thus, ultimately the result of the review indicates that a combination of all these three techniques can lead to a compact and minimized heat exchanger that uses the benefits obtained from both nanofluids and helically coiled tubes in order to improve the heat transfer rate of the thermal systems.

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Section: Microchannel Introductionmentioning

confidence: 99%

Heat Transfer Enhancement Using Passive Technique: Review

2021

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“…Dondapati et al [34] expressed a study that density, viscosity and thermal conductivity of nanofluid increase or decrease depends on the volume fraction of nanoparticles specific heat decreases or increases respectively. However, effective thermophysical properties were depend on both the volume fraction of nanoparticles and temperature.…”

Section: Introduction Of Nanofluidmentioning

confidence: 99%

Thermal behavior of phase change material (PCM) based cavity: experimental and numerical validation

Shak¹

2021

Preprint

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Recently, thermal energy storage (TES) includes technologies for collecting and storing energy for later use in domestic and industry by using Phase Change Materials (PCMs) which is a main topic for many researchers. In this experimental and numerical study, melting process and thermal behavior due to a U-shaped heat source embedded in the PCM is investigated which has been simulated in COMSOL-3D Multiphysics. The three-dimensional governing equation is solved for the fluid flow and heat transfer behavior. Two different cases are analyzed in this study. In the first case, the experimental results of a rectangular cavity filled with PCM, and a Ushaped heating source embedded in it is validated with a numerical model. PCM is used that has melting point temperature 32 °C, and flow of water at temperature 39 °C for six hours period through the U-shaped tube to intensify the PCM`s temperature. PCM melts and absorbs latent heat as energy which is analyzed horizontally and vertically. PCMs temperature increased uniformly with increasing of time inside the cavity. The melting rate was high around the heating source than the far distances of heating source. After six hours, 100% PCM was melted around the U-shaped tube, however, far from the U-shaped tube was not significantly melted in both experimental study and numerical model. The numerical results are in good agreement with the experimental data with a small number of relative error in all cases. In the second case, PCM and Bentonite are used in four different models in the same rectangular cavity, then hot-water and, cold-water flowing through the U-shaped tube, and the numerical results were validated for all models. It was observed that, when Bentonite is used, the heat transfer rate was higher compare to the case when PCM is used for anywhere in the cavity. The reason is that, Bentonite has higher thermal conductivity and temperature gradient than the PCM. So, Bentonite was more sensitive for heat transfer whenever used in heating or cooling. It is clear from this study that PCM and Bentonite can be a good media for storing thermal energy for later use such as room heating, space heating, industrial and commercial uses. PCM has a great possibility to it, because of its low initial and maintenance cost, and its availability.

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“…This can be done by making stable suspensions of ultra-fine solid particles and fibres with thermal conductivities higher than that of the base fluids [29,30], which is widely known as "nanofluids" [31]. However, the augmented viscosity of nanofluids can increase pressure penalty, particularly for MHSs [10,[32][33][34][35]. It is, therefore, essential to study nanofluid flow and heat transfer characteristics in MHSs to optimise the factors that influence the thermo-hydraulic performance of cooling systems.…”

Section: Introductionmentioning

confidence: 99%

Thermal and hydraulic performance analysis of a heat sink with corrugated channels and nanofluids

Naranjani

Roohi

Ebrahimi

2020

J Therm Anal Calorim

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Cooling of electronic devices is one of the critical challenges that the electronics industry is facing towards sustainable development. Aiming at lowering the surface temperature of the heat sink to limit thermally induced deformations, corrugated channels and nanofluids are employed to improve the thermal and hydraulic performances of a heat sink. Three-dimensional simulations based on the finite-volume approach are carried out to study conjugated heat transfer in the heat sink. Water-based nanofluids containing $$\hbox {Al}_{2}\hbox {O}_{3}$$ Al 2 O 3 nanoparticles with two different particle sizes (29 nm and 40 nm) and volume fractions less than 4% are employed as the coolant, and their influence on the thermal and hydraulic performance of the heat sink is compared with the base fluid (i.e. water). An empirical model is utilised to approximate the effective transport properties of the nanofluids. Employing corrugated channels instead of straight channels in the heat sink results in an enhancement of 24–36% in the heat transfer performance at the cost of 20–31% increase in the required pumping power leading to an enhancement of 16–24% in the overall performance of the heat sink. Additionally, the numerical predictions indicate that the overall performance of the proposed heat sink design with corrugated channels and water–$$\hbox {Al}_{2}\hbox {O}_{3}$$ Al 2 O 3 nanofluids is 22–40% higher than that of the water-cooled heat sink with straight channels. It is demonstrated that the overall performance of the heat sink cooled with water–$$\hbox {Al}_{2}\hbox {O}_{3}$$ Al 2 O 3 nanofluids increases with reducing the average nanoparticle size. Additionally, the maximum temperature rise in the heat sinks is determined for different thermal loads.

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Computational prediction of pressure drop and heat transfer with cryogen based nanofluids to be used in micro-heat exchangers

Cited by 31 publications

References 53 publications

Heat Transfer Enhancement Using Passive Technique: Review

Heat Transfer Enhancement Using Passive Technique: Review

Thermal behavior of phase change material (PCM) based cavity: experimental and numerical validation

Thermal and hydraulic performance analysis of a heat sink with corrugated channels and nanofluids

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