Showing papers on "Micro heat exchanger published in 2014"
TL;DR: A review of the heat transfer applications of nanofluids to develop directions for future work is presented in this article, where most of the results are in agreement with the results of experimental work.
Abstract: The low thermal properties of liquids have led to investigations into additives of small size (less than 100 nm solid particles) to enhance their heat transfer properties and hydrodynamic flow. To summarise the experimental and numerical studies, this paper reviews these computational simulations and finds that most of them are in agreement with the results of experimental work. Many of the studies report enhancements in the heat transfer coefficient with an increase in the concentration of solid particles. Certain studies with a smaller particle size indicated an increase in the heat transfer enhancement when compared to values obtained with a larger size. Additionally, the effect of the shape of the flow area on the heat transfer enhancement has been explored by a number of studies. All of the studies showed a nominal increase in pressure drop. The significant applications in the engineering field explain why so many investigators have studied heat transfer with augmentation by a nanofluid in the heat exchanger. This article presents a review of the heat transfer applications of nanofluids to develop directions for future work. The high volume fraction of various nanofluids will be useful in car radiators to enhance the heat transfer numerically and experimentally. Correlation equations can expose relationships between the Nusselt number, the Reynolds number, the concentration and the diameter of the nanoparticles. On the other hand, more work is needed to compare the shapes (e.g., circular, elliptical and flat tube) that might enhance the heat transfer with a minimal pressure drop.
182 citations
TL;DR: In this article, five different heat sinks with fin spacings of 0.2mm, 0.5mm, 1.0mm, and 1.5 mm along with a flat plate heat sink were investigated.
154 citations
TL;DR: In this paper, a computational fluid dynamics (CFD) study has been carried out to study the heat transfer and pressure drop characteristics of water-based Al 2 O 3 nanofluid flowing inside coiled tube-in-tube heat exchangers.
151 citations
TL;DR: In this article, a micro pin fin heat sink is numerically investigated with three fin geometries (square, triangular and circular) in addition to the unfinned microchannel heat sink.
143 citations
TL;DR: One of the leading tools used in passive heat transfer methods mainly at turbulence flow is twisted tape inserts and as discussed by the authors acclaims that want to review experimental researches done on this technique in recent years at the turbulent zone and with respect to the overall enhancement ratio pick the most efficient type of twisted tape.
134 citations
TL;DR: In this article, the effects of water and CuO/water nanofluids (as coolants) on heat transfer coefficient, heat transfer rate, frictional loss, pressure drop, pumping power and exergy destruction in the corrugated plate heat exchanger were examined.
134 citations
TL;DR: In this paper, single phase forced convective heat transfer and fluid flow of CuO/water and Al2O3/water nanofluids were experimentally investigated in a microchannel heat sink (MCHS).
134 citations
TL;DR: Based on constructal theory, five different cases with multistage bifurcations are designed as well as one case without bifurlcations, and the corresponding laminar fluid flow and thermal performance have been investigated numerically as mentioned in this paper.
126 citations
TL;DR: In this article, the experimental studies on flow visualization, pressure drop and heat transfer characteristics of microchannels presented by different researchers are summarized, some different flow patterns observed in microchannel geometry such as bubble nucleation in thin film, periodic variation of flow pattern, flow circulation, bubble suppression and cross-channel flow are explained briefly.
126 citations
TL;DR: In this paper, the effect of using the wavy-up and wavydown rectangular winglets as special forms of winglet is numerically investigated in a relatively low Reynolds number flow.
120 citations
TL;DR: In this paper, the hydraulic and thermal fields of a 29nm CuO nanoparticle-water nanofluid with various volume fractions, 0.24, 1.03% and 4.5%, were investigated inside a rectangular microchannel heat sink under both laminar and turbulent conditions.
TL;DR: In this paper, the authors reviewed the recent research of three kinds of surface heat exchangers, i.e., shell-and-tube heat exchanger with helical baffles, air-cooled heat exchange, and primary surface heat exchange.
TL;DR: In this paper, an energy harvesting system which extracts heat from an automotive exhaust pipe and turns the heat into electricity by using thermoelectric power generators (TEGs) was built.
TL;DR: In this paper, a new three-dimensional model for a magnesium-based metal hydride reactor with helical coil heat exchanger is proposed and solved using the commercial software package COMSOL Multiphysics V3.5a.
TL;DR: In this paper, a numerical model was developed to predict the flue-ash particle deposition rate by considering particles transport, sticking and rebound behaviors based on the software FLUENT, extended by user-defined functions (UDFs).
TL;DR: In this article, vertical Y-shaped bifurcation plates are designed into the heat sink, and then the corresponding laminar flow and heat transfer are investigated numerically.
TL;DR: In this article, a comparative evaluation of seven common configurations of channels used in plate-fin heat exchangers is presented, including plain, perforated, offset strip, louvered, wavy, vortex-generator, and pin.
TL;DR: In this paper, the authors discussed the heat transfer enhancement of micro oscillating heat pipes (MOHPs) using self-rewetting fluid (SRWF), and analyzed the thermo-physical properties of SRWFs and deionized water.
TL;DR: In this article, the authors investigated the thermal performance and thermal efficiency of a thermosyphon heat pipe charged with Al2O3-water/ethyleneglycol, (water-EG) and Al 2O3 -water/diethylenedlycol (water -DEG) nanofluids.
TL;DR: In this paper, six different exhaust heat exchangers were designed within the same shell, and their computational fluid dynamics (CFD) models were developed to compare heat transfer and pressure drop in typical driving cycles for a vehicle with a 1.2-liter gasoline engine.
TL;DR: In this paper, the authors present an overview of literature dealing with recent developments in the study of heat transfer using nanofluids in heat pipes and some important inferences from the various papers are also highlighted.
TL;DR: In this paper, a first step towards a system optimization of organic Rankine cycles is taken by optimizing the cycle parameters together with the configuration of shell-and-tube heat exchangers.
TL;DR: In this paper, a printed circuit heat exchanger (PCHE), a potential IHX concept for high-temperature applications, has been investigated for their heat transfer and pressure drop characteristics under high operating temperatures and pressures.
TL;DR: In this paper, two cases of heat exchangers (HEXs) which previously were used in exhaust of internal combustion engines (ICEs) are modeled numerically to recover the exhaust waste heat.
TL;DR: In this paper, the authors investigated the performance of concentric tube heat exchanger with twisted tape inserted corrugated tube and evaluated its impact on engine performance and economics through heat recovery from the exhaust of a heavy duty diesel generator.
TL;DR: Wang et al. as mentioned in this paper investigated the heat transfer performance of tunnel lining ground heat exchangers and its impact factors, including the flow rate, inlet water temperature, and pipe distance.
TL;DR: In this article, an attempt has been made to summarize and analyze the results of an examination of the air-side performance of spiral (or helical) fin-and-tube heat exchangers.
TL;DR: In this paper, a modified method for estimating the mean value of thermal contact resistance in a plate fin-and-tube heat exchanger is presented, based on the CFD simulations and experimental measurements.
TL;DR: In this article, the authors investigated the effect of inlet air flow maldistribution on the thermo-hydraulic performance of plate fin-and-tube heat exchangers.
TL;DR: In this article, a review of the state-of-the-art nanofluid studies in the area of forced convection heat transfer enhancement is presented, and the results for the heat transfer characteristics in internal flow with constant heat flux and constant wall temperature boundary conditions reported by various researchers have been compiled and reviewed.
Abstract: Nanofluids are suspension of nanoparticles (less than 100 nm) in the conventional base fluids. The dispersed solid metallic or non-metallic nanoparticles change the thermal properties like thermal conductivity, viscosity, specific heat, and density of the base fluid. Past studies focused on measuring the thermal properties of nanofluids. These suspended nanoparticles effectively improve the transport properties and heat transfer characteristics of the base fluids. Recently, heat transfer augmentation using suspensions of nanometre-sized solid particles in base liquids have been investigated by various research groups across the world. This paper reviews the state-of-the-art nanofluid studies in the area of forced convection heat transfer enhancement. The results for the heat transfer characteristics in internal flow with constant heat flux and constant wall temperature boundary conditions reported by various researchers have been compiled and reviewed. Further, in heat exchangers, the real boundary conditions are different from the constant heat flux and constant wall temperature boundary conditions. Over a span of 2 decades, the literature in this field is widespread; hence, this review would be useful for researchers to have a precise screening of a wide range of investigations in this area.