Showing papers on "Pressure drop published in 2015"
TL;DR: In this article, the use of TiO2-water nanofluid as a working fluid for enhancing the performance of a flat plate solar collector has been studied, and the results reveal the impact and importance of each of these parameters.
215 citations
TL;DR: In this article, the influence of functional covalent groups on the thermophysical properties of carbon nanotube base fluid was investigated experimentally, and it was found that increasing Reynolds number, Peclet number or fraction of nanomaterial would improve the heat transfer characteristics of the nanofluid.
195 citations
TL;DR: In this paper, the effects of thermophoresis, Dufour, temperature dependent thermal conductivity and viscosity of an incompressible electrically conducting Casson fluid flow along a vertical porous plate in the presence of viscous dissipation, n t h order chemical reaction and suction were investigated.
168 citations
TL;DR: In this article, the effects of wave amplitude, wavelength, volumetric flow rate and volume fraction of different types of nanofluids on thermal resistance, pressure drop, and friction factor of a microchannel heat sink were investigated.
165 citations
TL;DR: In this article, an enhanced microchannel heat sink with sectional oblique fin is used to modulate the flow in contrast to continuous straight fin, which resulted in better heat transfer and a comparable pressure drop.
146 citations
TL;DR: In this article, the effect of variation in the cylinder as well as the cone lengths on cyclone performance parameters with respect to the standard cyclone model is examined and comparison is presented among the two geometrical variables for similar increase in their lengths.
131 citations
TL;DR: In this paper, a double-pipe heat exchanger made of corrugated outer and inner tubes was investigated, where both of the inner and outer tubes were made by means of a special machine and the heat transfer coefficient was determined using Wilson plots.
126 citations
TL;DR: In this paper, a quasi-one-dimensional transient two-phase heat transfer model is used to assess the effect of operational and design parameters on the performance of thermocline thermal energy storage (TES) based on a packed bed of rocks and high-temperature air from process heat as heat transfer fluid.
125 citations
TL;DR: In this paper, the authors proposed a new design concept of microchannel heat sink, in which solid fins are replaced by porous fins, to reduce the pressure drop across the heat sink.
118 citations
TL;DR: In this paper, an experimental investigation has been made to compare the flow boiling characteristics of deionized water in three different configurations of microchannels, namely, uniform cross-section, diverging cross-sections and segmented finned channels.
118 citations
TL;DR: Study of the influences of vascular structure variation on the flow and pressure characteristics via microfluidic devices finds that RBCs drift from the center of the channels, and RBC velocity is influenced not only by the inlet flow rate but also the interaction between R BCs.
Abstract: The retinal arterial network is the only source of the highly nutrient-consumptive retina, thus any insult on the arteries can impair the retinal oxygen and nutrient supply and affect its normal function. The aim of this work is to study the influences of vascular structure variation on the flow and pressure characteristics via microfluidic devices. Two sets of micro-channel were designed to mimic the stenosed microvessels and dichotomous branching structure in the retinal arteries. Three working fluids including red blood cell (RBC) suspension were employed to investigate the pressure drop in the stenosed channel. The flow behaviors of RBC suspensions inside the micro channels were observed using high speed camera system. Pressure drop of different working fluids and RBC velocity profiles in the stenosed channel were obtained. Moreover, hematocrit levels of RBC suspensions inside the bifurcated channels were analyzed from the sequential images of RBC flow. The results of the flow in the stenosed channel show that RBCs drift from the center of the channels, and RBC velocity is influenced not only by the inlet flow rate but also the interaction between RBCs. The measured pressure drops in the stenosed channel increase notably with the increase of fluid viscosity. Furthermore, the dimensionless pressure drop due to the stenosis decreases with Reynolds number. On the other hand, the results of flow through the bifurcated channels show that as the ratio of the daughter-branch width to the mother-channel width increases, the ratio of hematocrit in two connected branches (Ht/Hd) decreases, which is in favorable agreement with the available analysis results.
TL;DR: In this article, the heat transfer and pressure drop characteristics of Al2O3/water and MWCNT/water nanofluids flowing in a chevron-type plate heat exchanger were experimentally investigated and compared with those of water.
Patent•
11 Mar 2015TL;DR: In this article, gas-phase reactors and their systems are described, including a spacer within a gap to control a flow of gas between a region and a reaction chamber, which can reduce a pressure drop along the flow of gasses through the reactor.
Abstract: Gas-phase reactors and systems are disclosed. Exemplary reactors include a reaction chamber having a tapered height. Tapering the height of the reactor is thought to reduce a pressure drop along the flow of gasses through the reactor. Exemplary reactors can also include a spacer within a gap to control a flow of gas between a region and a reaction chamber.
TL;DR: In this paper, the convective heat transfer coefficient and friction factor for fully developed turbulent flow of graphene nanoplatelet (GNP) nanofluids of varying specific surface areas flowing through a horizontal stainless steel tube with a uniform heat flux are experimentally determined.
TL;DR: In this article, both numerical and experimental studies on the hydrodynamics and heat transfer of two-phase flow without phase change in small channels and tubes are reviewed and a perspective on future directions in the field is suggested, including control through wettability and the use of novel liquids.
TL;DR: In this paper, the effect of the length of Y-shaped bifurcation and the angles of the arms on the overall performance of the microchannel heat sink was examined, and the thermal and fluid flow characteristics were investigated numerically.
TL;DR: The benefits of using pin fin heat sinks with multiple perforations using complementary experimental and Computational Fluid Dynamics (CFD) methods were investigated by as mentioned in this paper, which showed that the effect of perforated pin fin design on heat transfer and pressure drops across the heat sinks was found to agree with predictions from a CFD model for the conjugate heat transfer into the cooling air stream.
TL;DR: In this article, the predictive model based on least square support vector machine (LSSVM) was used to estimate the amount of dissolved calcium carbonate concentration in oil field brines.
TL;DR: In this article, the effects of geometric properties of each porous layer on the thermal performance were investigated, and the results indicated that the thickness of the first porous layer has significant effect on the temperature field and pressure drop.
TL;DR: In this paper, a prismatic spouted bed was characterized experimentally and modelled by means of 3D CFD-DEM simulations, where the main focus was on the investigation of the influence of the gas flow rate on the bed dynamics and spouting stability.
TL;DR: In this paper, a simple new equation (fV = −160 + 2.81Rem0.904) was proposed to represent the data collected in this work, which yields the smallest mean error among all the correlations considered here.
TL;DR: In this paper, two approaches were evaluated: Response Surface Methodology (RSM) applying Neural Networking method, and Direct Optimization (DO) for heat transfer enhancement in a fin-tube heat exchanger.
TL;DR: In this article, double emulsion drop formation in flow-focusing microfluidic device is investigated numerically by computational fluid dynamics simulation using VOF method, and the simulation produces two typical drop formation modes, including dripping and jetting, and provides the detailed hydrodynamic information underlying these two modes.
TL;DR: In this paper, the influence of material type and PSD on both particle properties (sphericity) and packed bed properties (voidage and Sauter mean diameter) have been investigated.
TL;DR: In this paper, a two-phase mixture model was used for modeling the convective heat transfer coefficient and the pressure drop in a shell-and-tube heat exchanger equipped with helical baffles.
TL;DR: In this paper, the authors used non-dominated sorting genetic algorithm-II (NSGA-II) to optimize the geometrical parameters of chevron type plate evaporator for a low temperature geothermal ORC system.
TL;DR: In this article, the authors compared straight-finned and oblique finned microchannels with similar channel dimensions and operating conditions using the FC-72 dielectric fluid.
TL;DR: In this article, the local heat transfer coefficient during condensation of R1234ze(E) is investigated in a single minichannel, horizontally arranged, with hydraulic diameter equal to 0.96 mm.
Abstract: R1234ze(E), trans-1, 3, 3, 3-tetrafluoropropene, is a fluorinated propene isomer which may be a substitute of R134a for refrigeration applications. R1234ze(E) has a much lower GWP100-years than that of R134a. In this paper, the local heat transfer coefficient during condensation of R1234ze(E) is investigated in a single minichannel, horizontally arranged, with hydraulic diameter equal to 0.96 mm. Since the saturation temperature drop directly affects the heat transfer rate, the pressure drop during adiabatic two phase flow of R1234ze(E) is also measured. Predictive models are assessed both for condensation heat transfer and pressure drop. A comparative analysis is carried out among several fluids (R1234ze(E), R32, R134a and R1234yf) starting from experimental data collected at the same conditions and using the Performance Evaluation Criteria (PEC) named Penalty Factor (PF) and Total Temperature Penalization (TTP) to rank the tested refrigerants in forced convective condensation.
TL;DR: A comprehensive literature survey on the thermal-hydraulic performance of liquid flow and heat transfer in pipes with internal integral-fins, twisted tape inserts, corrugations, dimples, and compound enhancement techniques is conducted in this paper.
TL;DR: In this article, the authors carried out an experimental study on the transportability and pressure drop of coal gangue-fly ash backfill slurry through a pipe loop system built in laboratory.