Abstract The prediction accuracies of the two-phase heat transfer coefficient for the flow in a small channel, which are usually based on the mean absolute error (MAE) between the correlation and experimental data, have remained unsatisfactory. Conventionally, the regression method has been used to determine the correlation that best represents the experimental data. In this paper, an improved heat

Abstract Access to drinking water in many parts of the globe is shrinking over the years and much of the water resources are polluted or unpurified. North Africa is facing a huge water shortage due to drought and climate change. Water desalination has become very popular and serves as solar distillation which is proving to be an economical, simple and ecological technique, especially in rural and remote

Abstract In this paper, an experimental study was carried out in order to investigate the effects of Al2O3/water nanofluid with a mean diameter of 50 nm on heat transfer performance in a counter flow double-pipe heat exchanger. The nanofluid was used as cold side fluid and passed through the inner pipe of the double-pipe heat exchanger considering fully developed turbulent flow regime with different

Abstract This study investigated the numerical analysis of Nusselt number and entropy generation of copper/water nano-fluid under turbulent flow conditions at volume fraction ranges of 1–5% within a helical coil under constant heat flux. The nano-fluid behavior was modeled through a single-phase model. Flow and heat transfer governing equations were discretized using finite volume method, and the SIMPLE

Abstract The transient temperature measurements and subsequent prediction of heat flux are prime requirements to quantify instantaneous heat transfer characteristics in short duration unsteady flow phenomena. Coaxial surface junction thermocouples (CSJT) are efficient laboratory tools that can cater both the requirements of measuring continuous as well as instantaneous temperatures. In addition, they

Abstract In this study, the production of green olive, chickpea and haricot bean added potato chips was investigated in order to produce a functional snack food appealing to consumers from all age groups. Chips were produced by hot air drying (75–85 °C), vacuum drying (75–85 °C, 250 mbar), and microwave drying (90 W and 180 W). The effective diffusion coefficient of chips was calculated as between

Abstract The impingement behavior is inevitable during the injection process of urea water solution in selective catalytic reduction aftertreatment system of diesel engine. The impingement contributes to the formation of liquid film on the pipe wall and mixer, and it will block the pipe and reduce the urea water solution decomposition efficiency. In this work, the morphological changes of the spray

The article Experimental assessment of Al2O3 and Cu nanofluids on the performance and heat leak of double pipe heat exchanger, written by Esam I. Jassim & Faizan Ahmed, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 16 January 2020 with open access.

Abstract Several numerical and experimental studies of natural convective heat transfer from two-sided heated horizontal plates are available. In the numerical studies it has usually been assumed that the plate is thin, effectively having no thickness, whereas plates of finite thickness have been used in the experimental studies. The main aim of the present study is to determine whether the plate thickness

Abstract Velocity and concentration profiles in a pipe flow was measured downstream of injection of a tracer gas at the pipe centerline. The pipe had diameter D = 0.2 m and two Reynolds numbers, Re = 50000 and Re = 100000, were used. The profiles were measured at positions 5D and 10D downstream of the injection point. Three different industrial relevant geometrical configurations were used upstream

Abstract Sodium chloride salt is used in the cheese salting because it promotes sensorial changes besides preserving the food, but in excess can cause hypertension. Therefore, it has been partially replaced by potassium chloride to not affect the sensory characteristics. In this work the mozzarella cheese was subjected to the diffusion of Na+ and K+ in brine by static and stirred immersion. The diffusion

Abstract Based on the thermal integrity testing method of foundation pile, distributed optical fiber temperature sensing (DTS) technology was applied to testing the integrity of a cast-in-place pile. A theoretical model was established for the heat transfer and temperature characteristics in consideration of the physical properties of piles and the surrounding media. By establishing a model of a pile

Abstract With the increase in laser technology for ophthalmic surgeries, the knowledge of the heat transfer mechanism in the human eye becomes increasingly important. The accuracy in predicting thermal behavior is linked to the use of adequate thermal and numerical methods. In this way, this study presents the results of two two-dimensional models, cartesian and axisymmetric in cylindrical coordinate

Abstract The current numerical study has explored the effect of incorporation of rectangular winglets with circular, flat and oval tubes on the performance of compact heat exchangers. Rectangular winglet pairs are mounted behind the tubes at a span angle of 5° to obtain the enhanced performance. The obtained results show that fin and oval tube heat exchanger (FOTHE) having rectangular winglet pairs

Abstract Heat exchanger fouling is a complex process and closely associated with the operating conditions and surface properties. Many studies have been carried out to model various stages of the fouling process. These include the induction period, initial fouling rate (IFR), and fouling growth. Among them, IFR is of primary importance since its reduction leads to a longer operating time. Several studies

Abstract One of the common problems of water-cooled panels which is carrying off-gas from Electric Arc Furnace is cracking and punching in their steel bodies due to the high thermal stresses which cause water leakage into the furnace and delaying the production. In this study, heat transfer in the elbow of water-cooled panels was simulated in the steady and transient states using computational fluid

Abstract Boiling utilizes latent heat of vaporization of the fluid to dissipate large amount of heat at small temperature budgets. Surfaces with micro−/nano-scale wettability patterns have been shown to improve the heat transfer coefficient during pool boiling. In this work, we propose a simple and cost-effective technique to fabricate heterogenous surfaces with macroscale wettability patterns comparable

Abstract Considering equipment damage, energy consumption enhancement and efficiency reduction during undesirable solidification process, this paper experimentally investigated the ability of clay nanoparticles to hinder the solidification procedure. The nanofluids were prepared by dispersing various concentrations of clay nanoparticles (0.01 wt.%, 0.02 wt.% and 0.04 wt.%) in deionized water without

Abstract The present experimental study aims to investigate condensation heat transfer characteristics of R600a/oil/multi-walled carbon nanotube (MWCNT) nano-refrigerant flow inside a horizontal micro-fin tube. The test condenser is a horizontal double-pipe heat exchanger consists of a copper micro-fin tube with 14.18 mm inner diameter which is installed in a polyethylene shell with a diameter of 6 cm

Abstract Radial inflow turbine and nozzle among the other components of the cryogenic turboexpander has a significant effect on the efficiency of the system. This study proposes an effective one-dimensional design approach of a radial turbine by introducing different loss correlations. The methodology also describes the effect of non-dimensional design variables on the performance of the turbine. These

Abstract The current technical note is an expression for extending aspects of the previous work of Ajib and Karno [1] which related to the thermophysical properties of acetone / ZnBr2. The study covers the thermal conductivity of a solution which appears to be a promising fluid for operating vapour absorption refrigeration (VAR) systems from a low temperature source. It covers also an investigation

Abstract Heat and mass transfers’ equations of hydrocarbon liquid droplet are solved numerically by using a semi-implicit method based on the finite volume scheme (VOF). The Piece-wise Linear Interface Calculation (PLIC) is used in our modeling. A curvature estimation technique based on PLIC-VOF method is developed. The determination of the normal vector based on the calculation of the curvature is

Abstract Binary distillation in continuous contact equipment is an important section in the oil refinery. In order to provide information about the temperature of the phases as well as the compositions, the heat and mass transfer that are nonlinear should be solved simultaneously. In this research, the heat and mass transfer of the binary distillation in a vertical wetted wall column is solved using

Abstract This paper provides a comprehensive review of the published experimental researches on condensation heat transfer inside plain tubes. The existing methods of the research on heat transfer and hydrodynamics have been analyzed and their disadvantages are substantiated (shown). There are considered more than 40 empirical and semi-empirical methods and correlations for prediction of heat transfer

Abstract An impinging jet heat transfer in cross-flow within and without influence of a vortex generator pair (VGP) is studied using the unsteady Reynolds averaged Navier-Stokes (URANS) and the large-eddy simulation (LES). The jet Reynolds number is 15,000 and the cross-flow Reynolds number is 30,000. The elliptic-blending Reynolds stress model (EBRSM) is implemented and adapted to capture the effect

Abstract In this study, experiments were performed to investigate the flow boiling of deionized water in a rectangle (1 mm × 2 mm) horizontal long mini channel, and visualization experiments were carried out to study the transformations of flow patterns. Uniform heating (UH for short) and step-changing heating (SCH for short) were studied. The local heat transfer coefficients during both heating methods

Abstract Rice (Oryza sativa L.) is one of the most produced and consumed cereals in the world, being characterized as the main food of more than half of the world population, since it is source of energy, protein, vitamins and minerals. Freshly harvested rice from the field generally has a high moisture content to be stored safely and, therefore, a suitable drying process needs to be conducted to decrease

Abstract This paper reported experimental and numerical simulation investigations on heat transfer characteristics of polygonal twisted elements in the constant wall temperature with Reynolds number (Re) ranging from 200 to 1800. In this study, the results revealed that the entransy efficiency (η) increased with the polygonal twisted element’s edge number increasing. Moreover, the highest entransy

Abstract The present article is focused on two phase heat transfer experiment, conducted over plain and porous coated circular tube of 20 mm diameter with 130 mm heating length in the quiescent pool of fluid at atmospheric pressure. The heat flux is varied from 20.19–70.22 kW/m2. The concentration of SDS and TritonX-100 are varied from 100 to 1200 ppm and 100–400 ppm in NaCl solutions respectively

Abstract Produce of continuous-dehumidified air free from traces of water vapour is essential in many industrial applications. Temperature swing adsorption (TSA) system and heatless based pressure swing adsorption (PSA) system are generally used to produce ultra-low dew point temperature dehumidified air. In this work, an internally heated TSA system is developed and investigated for its suitability

Abstract This paper aims at investigating the hygroscopic behavior and the thermodynamic characterization of the dandelion (Taraxacum officinale) leaves and root during moisture sorption phenomena. This study has been conducted by using the saturated salt solutions at different temperatures 30 °C, 40 °C and 50 °C. The obtained isotherms curves of all samples were of sigmoidal Type II. The optimal water

Abstract Present work studies experimentally the flame characteristics of a premixed natural gas/air mixture in a porous-free flame (PFF) burner, and also it is compared with a conventional porous burner. For the PFF burner a hole is created at the center of the porous foam, which has a porosity of 87%, height of 22 mm and diameter of 90 mm, making a combination of a free flame and a flame in the porous

Abstract This paper presents a study of a new tubular vaporizing liquid micro-thruster (VLM) with induction heating. The developed micro-thruster consists of a micro-heater core, an excitation coil, a vaporizing chamber, a nozzle and a micro-channel, all integrated in a glass tube with a dimension of 3 mm (outer diameter) × 18 mm (length). The temperature of the micro-heater core is tested with experiments

Abstract A domestic cookie baking process was modeled using nonlinear forward and inverse models to predict surface temperature, moisture content and browning index that describe the baking quality of the end product. The baking processes were carried out at different oven temperatures (160, 180, 200 °C) and the changes in surface temperature, moisture content and browning index were determined to

Abstract Thermal properties of sand are of importance in numerous engineering and scientific applications ranging from energy storage and transportation infrastructures to underground construction. All these applications require knowledge of the effective thermal parameters for proper operation. The traditional approaches for determination of the effective thermal property, such as the thermal conductivity

Abstract Due to the high thermal conductivity, graphene could be used as a filler in matrix materials to improve the thermal performance. In this paper, the thermal conductivity and interfacial interaction of graphene/polyamide (GE/PA6), graphene/polypropylene (GE/PP) and graphene/high density polyethylene (GE/HDPE) composites with different graphene mass fractions were studied by melt-blending experiments

Abstract As the Zizania latifolia has a delicious taste, high nutritional value and rich moisture, it is easy to rot and deteriorate due to the high moisture content, resulting in short shelf life. In order to maintain quality of Zizania latifolia, the vacuum cooling process of cylindrical vegetables is experimentally studied. Considering the transient heat transfer and mass conservation, a mathematical

Abstract In this present work, round jet impingement on a heated flat plate at constant heat flux is analysed experimentally and numerically. Experiments have been performed at various Reynolds numbers (Red = 10,000 to 25,000) and at four different nozzles to plate spacing (h/d = 4, 6, 8 and 10). Different RANS turbulence model namely, k-ω SST, Realizable k-ε, RNG k-ε and ν2f were used to validate

Abstract Nanofluids have been introduced to improve the thermal properties of phase-change materials. However, stability problems caused by agglomeration and deposition have greatly restricted the use of nanofluids. In this work, paraffin-based nanofluids were prepared under the dual coordination of magnetic stirring and ultrasonic oscillation, the influence of ultrasonic power and time, base fluid

Abstract The cooling performance of a vehicle radiator was experimentally investigated using pure water, graphene oxide (GO) and graphene nano ribon (GNR) nano-fluids in this paper. Three different fluid inlet temperatures (36, 40 and 44 °C) and four different flow rates (0.6, 0.7, 0.8 and 0.9 m3 h−1) were performed in the experiments. GO and GNR nano-fluids were obtained at 0.01 and 0.02% vol. concentrations

Abstract Condensing gas boilers are widely employed for their high heat efficiency, which attributes to their ability to use the recoverable sensible heat and latent heat in flue gas. In this paper, the optimal excess air rate of a novel condensing gas boiler is investigated experimentally. With the change of excess air rate, the pre-mixed and post-mixed systems were used to study the performance,

Abstract Various design configurations of semi-T-shaped dual-channel micro-reactors were numerically examined for their laminar mass transport performance in heterogeneous catalytic combustion of methane and air. One single-channel and five dual-channel configurations (i.e., parallel, divergent, convergent, zig-zag, and curved configurations) were investigated with a two-dimensional computational fluid

Abstract The development of additive technologies such as gas-phase deposition provides the possibility of applying various coatings with different properties. The study introduces a model of heat conduction which relies on the specific character of heat and mass transfer in chemical gas-phase deposition on a curvilinear surface with a linear change in the curvature over the shell thickness. A difference

Abstract Application of the method of fundamental solutions in combination with the global radial basis function collocation method for analysis of fluid flow and heat transfer in an internally finned square duct is presented in the paper. Fluid flow problem is solved using the modified method of fundamental solutions. After that, the average fluid velocity and product of friction factor and Reynolds

Abstract Detailed flow field and heat transfer characteristics developed in a row of three co-rotating dual swirling impinging flames have been investigated experimentally as well as numerically. Impingement heat transfer and pressure distribution has been studied experimentally at different separation distances and inter-jet spacings. Inverse heat conduction procedure (IHCP) has been used for estimating

Abstract Reduction of the stenosis in arteries is one of the most important applications of nanoparticles in medicine. Thus, investigating nanoparticles in stenosed arteries is a subject attracting so much attention from the researchers nowadays. However, considering the small size of arteries, it seems that non-classical theories demonstrate better results when compared to the classical Navier-Stokes

Abstract The kinetics of degradation of pharmaceutical drugs is studied by ozonation in a fine bubble system. In the present experimental work, fine bubbles of ozone were used for degradation of pharmaceutical drugs soluble in water. The ozonation of pharmaceutical drugs by ozone bubbles was found to be very effective at high pH and high ozone flow rates. The apparent reaction rate constant was estimated

Abstract New empirical models for evaluating heat-transfer coefficients for condensation on banks of tubes were developed using an experimental database of over 4000 individual data points for 7 different condensing fluids and 13 different tube bank configurations. New empirical models within each of the free and forced convection flow regimes for both of the steam and non-steam fluids separately were

Abstract In this paper, a three-dimensional computational fluid dynamics model based on the finite volume method is developed for an anode-supported solid oxide fuel cell with an active area of 1.54 cm2. The numerical model including electrochemical reaction has been compared with experimental data obtained under the same conditions to verify the reliability of the code, air and fuel concentrations

Abstract Thermal management is highly essential for the latest electronic devices to effectively dissipate heat in a densely packed environment. Usually, these high power devices are cooled by integrating micro scale cooling systems. Most of the works reported in the literature majorly concentrate on microchannel heat sink in which the characteristics of friction factor and enhancement of heat transfer

Abstract This “study deals with fabrication, physico-chemical characterizations and thermal properties of AP25 nanocapsules as organic PCM (phase change materials) for TES. The influence of reaction temperature and stirring rate on the properties of phase change materials nanocapsules was studied using RSM method. The FESEM and TEM micrographs show that nanocapsules are uniform of spherical shape with

Abstract The purpose of this paper is to theoretically investigate the steady nanofluid flow due to a permeable stretching/shrinking cylinder using the mathematical nanofluid model proposed by Buongiorno. The effects of the stretching/shrinking parameter as well as the suction and curvature parameters are studied. A similarity transformation is used to reduce the governing partial differential equations

Abstract Effect of helical perforated twisted tape parameters like diameter ratio (dR/DI), relative pitch ratio (PPT/LT), perforation index (PA/TA) and Reynolds number(Re) on the thermal and hydrodynamic performance of heat exchanger circular tube experimentally analysed. Experimental data pertinent to air flow and heat transfer is generated and thermal hydrodynamic performance is determined for different

Abstract Improving the heat transfer coefficient of working fluids is essential for achieving the best performance of manufacturing systems. As a replacement of conventional working fluids, nanofluids have a high potential for improving this heat transfer coefficient. However, nanofluids are seldom implemented in actual systems, and several factors should be considered before actual application. Accordingly

Abstract The influence of cooling models and moving velocity on the temperature variation and cooling rate through the thickness of a metal plate is experimentally investigated. In this investigation, the cooling process is divided into four stages: a starting stage (I), a rapid cooling stage (II), a slow cooling stage (III) and a stopping stage (IV). Based on the curves, cooling rate, temperature

Abstract The heat transfer characteristics of shell-and-tube exhaust gas recirculation (EGR) coolers with different tube bundles were studied by experiment and numerical simulation. The overall heat transfer coefficient and shell-side pressure drop were determined. The influences of tube spacing, baffle form, baffle arrangement and number on the overall heat transfer coefficient and shell-side pressure

Abstract In this work, analytical solutions of the thin-layer and the Luikov models were proposed. For the thin-layer model, the moisture content and temperature distribution inside a biomass, assimilated to a parallelepiped material, are uniform whereas the Luikov model considers the sample as a porous medium. Analytical solutions of the Luikov model equations were obtained using Hermite’s zero-order

Abstract Studies presented in this paper concern wide issue of thermal comfort of protective clothing. The Computer Aided Design (CAD) software tools to analyze thermal insulation of multilayer textile assembly used in thermal protective clothing were applied. First, 3D geometry and morphology of a real textile assembly was modeled. In the designed model different scales of resolution were used for

Abstract The aim of this work was to evaluate the influence of drying temperature on the convective drying process of clay sample as well as on the effective diffusivity. The study was performed on Tunisian raw-clay product in here simple spherical geometry with initial moisture content of 0.35 kg water/kg d.b. Air-drying characteristics were investigated in a laboratory convective dryer for a temperature

Abstract In this work, a new method of bricks making based on waste paper has been developed for the thermal insulation of buildings. This method involves converting paper waste into aggregates and combining them with a Portland cement binder. A physical and thermal characterization of the Aggregate of Waste Paper (AWP) is carried out, followed by a structural study by Scanning Electron Microscopy