The present investigation emphases on rotation effects on internal cooling of gas turbine blades both numerically and experimentally. The primary motivation behind this work is to investigate the possibility of heat transfer enhancement by dean vortices generated by Coriolis force and U-bend with developing turbulent in the view point of the field synergy principle and secondary flow intensity analysis

A great number of studies have been conducted pressure drop for packed bed and curved channel. However, pressure drop in the spiral packed beds has not been investigated. In this study, pressure drop in spiral packed beds which are made of two different channel widths (a = 10 mm and a = 15 mm) and three different ball diameters (d = 2.00, 2.38 and 3.17 mm) was investigated experimentally. Experiments

In the present work, conical frustums (d/D = 0.3) are used as turbulators to form an insert of a heat exchanger tube. Both the perforated and imperforated conical inserts in a diverging arrangement (DR arrangement) are experimentally studied. The effects of the parameters like pitch ratio (p/D), the number of perforated holes (N), and relative location of perforations (x/L) on thermal and fluid characteristics

Fouling phenomena, generally related to heavy crude oils and bituminous petroleum fractions, nevertheless affects significantly the preheat train (PHT) of the light Algerian crude oil. In this study, a two dimensional model was developed using the computational fluid dynamic (CFD) method in order to investigate fouling behavior in the PHT of Algiers refinery. A fouling model was proposed specifically

Salted chickpea (Cicer arietinum L.) is increasingly used in snack production and in home cooking by soaking in brines. Order to achieve better quality and higher nutrient content, it is important to model and understand the mass transfer processes during this operation. In this work, brine salting of chickpea was studied at 1, 5 and 20% salt concentrations, at temperatures of 25, 50, 75 and 100 °C

This study aims to examine and optimize the solvent extraction process of two different liquid-liquid systems, including toluene–acetone-water and n-butylacetate–acetone-water, in a perforated rotating disc contactor (PRDC) pilot plant according to response surface methodology (RSM). The interaction effects of four influential parameters of dispersed phase velocity, and continuous phase velocity, rotor

The thermal conductivity of soil is a fundamental physical property related to heat conduction and also one of the widely applied parameters in geotechnical engineering. Thermal needle tests were performed to measure the thermal conductivity of transparent sand. The thermal conductivity of three particle sizes of transparent sand was measured at different porosities and temperatures. The result shows

Temperature and pressure ratios in gas turbines have grown over time to increase the performance and efficiency of the engine. This, in turn, has required improvements to the effectiveness of the secondary air system to enhance the cooling performance of critical components. Analysis of pressure losses in the secondary systems of aero gas turbines has identified a significant contribution in the bled

Recently, the quality of food solar dried has been associated to solar irradiance, irradiation and UV-light. Different materials used as covering materials in direct solar dryers had different optical properties, thus, different quality should be expected in solar food drying. The objective of this study was to compare two direct solar dryers builder with different covering materials: Direct Solar

This paper reported numerical simulation investigations on heat transfer performance of ZrO2-water and Cu-water nanofluids in the tube with concentric double twisted element(CDTE)(Re = 6000-12000). Furthermore, experiments verified that the two-phase flow model method was more suitable for the numerical simulation of nanofluids in the tube with CDTE. The Nusselt numbers with CDTE and nanofluids obviously

The present work introduces an experimental analysis of an array of 12 elements including two heat sources and the rest are dummy elements. The effect of the second heat source position on the heat transfer coefficient (HTC) of both heat source elements within the Reynolds number range of 4108 ≤ ReL ≤ 17,115 is studied. Moreover, 3D (CFD) numerical model is introduced and its predictions are compared

Open sun Crops drying is common in India even though a considerable time and dust accumulated. This is a serious issue. Workman ship and time reduction is needed to increase the productivity. Introduction of Green house solar dryer should be a right choice as against the conventional drying. The novel research focuses for retaining the nutritional values at higher level, very clean and with very less

The objective of this study is to re-examine the classical parallel and classical series models of the effective thermal conductivity of porous media and review the underlying assumptions used to develop these asymptotic models. The Langmuir shape factor concept is introduced to gain insight into these classical models and add extra degrees of freedom to formulate semi-empirical correlations for the

An existing laboratory scale solar energy accumulator based on phase change materials was adapted to study experimental and analytically its thermoelectric capabilities. Electric power generation levels were assessed to energize low powered systems. Variables of the study were the circulating air velocity at two levels and the cooling convection mechanism on the cold face of the thermoelectric modules

The thermal performance of a double tube two-phase closed thermosyphon (DTTPCT) using alumina nanofluid as working fluid in startup, steady state and shut down modes has been experimentally and theoretically evaluated. Gamma-Alumina (γ-Al2O3) nanoparticles with size of 40 nm were well dispersed, prepared and stabilized in distilled water base fluid at different particle concentrations.The axial wall

The accidental spilling of cryogenic liquid leads to formation of a spreading pool, which may result in pool fires, BLEVE(boiled liquid evaporate vapor explosion) or vapor cloud fire, such as liquefied natural gas, is flammable. The key aspect of evaluating the consequence of such a disaster is to predict vaporization rate of the spreading cryogenic liquid pool. In this study, an empirical function

With the continuing development in the electric industry, highly efficient heat dissipation is of great significance due to the shrinkage of electric elements and increase in energy input. Working fluid, acting as a heat transfer medium, plays a core role in the thermal management. While, traditionally used working fluids suffer from either low thermal conductivity or relatively narrow liquid range

A modified so-called standard apparatus for heat transfer measurements in highly viscous binary fluids has been developed. It covers a viscosity range from 0.2 mPa∙s up to 1000 Pa∙s and is designed for measurements over a temperature range from 273 to 423 K. Concept and setup of the apparatus are described in detail, and uncertainties of the different elements of the measurement chain are discussed

The quantity of energy consumers in the country is extensive in the current quick-moving situation; the whole car industry puts a significant part in energy utilization. Biofuels have lured consideration among other alternative fuels as indicated by their natural element and synthetic creation.In this test, the aluminum nanoparticles are prepared by three various proportions (50, 100 and 150 ppm) being

The thermal enhancement and pressure drop in a circular tube with radially-arrayed winglet vortex generator (VG) mounted inside at different orientations were experimentally studied. A series of four winglet rings containing VGs were on the inner surface of the tube at different sections. The effects of winglet attack angles β (0–45°), pitch ratios PR (1.6–4.8), porosity ratio γ (0–20%), winglet length

A scale analysis has been performed to investigate the film boiling heat transfer associated with cooling of a horizontal flat plate through water jet impinging. The forced convection film boiling of water is treated by classifying a wide spectrum of subcooling regime by two extreme situations of low and high subcooling dominated by mass evaporation and sensible heating respectively. A simple expression

The effects of bubble size, solids particle (impurities) and the respective physical mechanisms on gas–liquid columns have received little attention. Therefore, the objective of this work is to study the effect of solid concentration and the ratio of the bubble diameter to the solid diameter on the mass transfer characteristics. Experiments were conducted in a three phase electroflotation column for

We studied the heat transfer of finned heat exchanger configurations with a novel design. These novel fin designs use integrated pins to enhance the heat conduction from the fin base to the fin tip as well as the air-side heat transfer on the fin surface. Oval tubes with conventional circular plain fins (CPF) as well as novel circular integrated pin fins (CIPF) and serrated integrated pin fins (SIPF)

Growing technological developments to improve the thermal efficiency of heat pipes resulted in many innovative techniques. The use of nanofluids with superior thermophysical properties compared to conventional fluids is one such technique. However, the service life of nanofluid driven heat pipes is affected by agglomeration and stability issues, demanding an alternate solution. Boiling heat transfer

Enhanced heat transfer through minichannel heat sink is beneficial for engineering uses such as air conditioning, cooling system, and heat retrieval processes. In the current study, the heat transfer and friction factor were experimentally measured in a rectangular minichannel heat sink with coiled wire inserts. These coiled wires exhibited two wire diameters (0.4, 0.6 mm) and three pitches (1.2, 2

During the construction of clay core rockfill dam in cold regions in winter, the heat transfer characteristics of gravelly soil are important to the anti-freezing control of the core. Laboratory experiment and field test data showed that the frost depth of gravelly soil in unconsolidated state was deeper than that in compacted state at the early period of soil freezing. With the increase of the freezing

This study experimentally investigated the heat transfer characteristics of the heat sink situated in a rectangular channel with the axial main flow under a transverse synthetic jet. The heat sinks, made of aluminum alloy, were divided into three kinds: the finned heat sinks, the in-line pin-fin heat sinks and the pure aluminum-foam heat sink. Total 7 heat sinks were used as test specimens. There was

Limiting current density data were obtained at point electrodes fixed flush with inner surface of the outer cylinder of an electrochemical cell in which a coaxially placed cylindrical rod is rotated at different rotational velocities in the presence of fluidizing solids. The variables covered in the present study are rpm of inner annular rod, diameter of rod, solid fraction and flow rate of the electrolyte

An experimental study on the contact angle dynamic during the impact of single water droplet onto a hot flat practical stainless steel surface under medium weber number was performed. The tested solid material was practical stainless steel of SUS 304. The surface roughness of the hot surface, the static contact angle at ambient pressure, and the diameter of the solid materials were respectively Ra = 0

The present works focus on the preparation of a novel bio-diesel from Methyl esters fish oil and assessment in a compression ignition engine. The process is optimized with different oil-methanol ratio and catalyst concentration to obtain a maximum yield of 99%. With that purpose, B20, B30, and B40 (by volume) of biodiesel and isobutanol was added to diesel to make different blends, and its properties

The aim of the study was to investigate the impact of combined application of pulsed electric fields (PEF) and ultrasound (US) pre-treatment on drying kinetics, mass transfer and convective water diffusion coefficient on plum fruit. The treatment was performed by using plum fruit in water for uniform distribution of electric conductivity and PEF treatment was applied at 1, 2 and 3 kV/cm, 50 pulses

The estimation for interfacial heat transfer coefficient (IHTC) between casting and mold is paramount to predict solidification phenomena. In this study, three hydraulic pressures of 30, 60, and 90 MPa were applied to indirectly squeeze cast magnesium alloy AZ91 in a P20 steel mold with five casting section thicknesses of 2, 4, 8, 12, and 20 mm, named steps 1, 2, 3, 4 and 5, by using a 75-ton hydraulic

Many new insulation materials are being developed and thermally tested aiming at understanding and improving their insulation characteristics in order to improve the energy performance of new and existing buildings. Bio-sourced materials appear among the new insulation solutions presenting the advantage of being able to save energy on one hand and having a low environmental impact on the other. The

This paper presents a new non-contact transient method for measuring the heat transfer coefficient. The proposed method is based on measuring the temperature response of the surface temperature to the heat flux irradiating the same surface, which is affected by the heat transfer coefficient on the back of the surface. The theoretical solution of this problem together with the measured experimental

An experimental and numerical study was carried out to investigate matrix-fracture thermal transport in fractured rock. Two different synthetically fractured core plugs were used during the flow-through experiments while core plugs’ outer surface was maintained at two different constant temperatures. To investigate the matrix-fracture thermal transport, cold water was injected through the single fracture

Crab stick by-product is the underspecification product from crab stick production. The by-product contains high moisture content inducing a short shelf life. Therefore, drying is considered as a food preservation technique to extend its shelf life. This study is focused on an investigation of desorption isotherms, drying characteristics and rehydration properties of crab stick by-product. Desorption

Experimental investigations have been carried out for impingement heat transfer characteristics of an enclosed dual swirling flame for various enclosure configurations. Effects of the size of the enclosure (DE = 70 mm, 90 mm, 90 mm, 110 mm and 150 mm) and the level of gap between the top of the enclosure and the target surface (G = 12, 16, 20, 24 and 28 mm) have been examined at fixed other operating

Due to the development of the electronic components, concentrator photovoltaic, fuel cell, etc., the cooling requirement of the devices increases rapidly. Due to the higher heat transfer and compact design of the microchannel technology, it has been widely considered and investigated to solve the increasing heat flux. Boiling heat transfer is an effective way to dissipate a mass of heat using the latent

Fouling is the unwanted deposition of soils on heat transfer surfaces and is a major challenge for industry and has been s subject to scientific investigations for decades, still being an unsolved problem for many applications. A fouling situation is commonly quantified with the thermal fouling resistance describing the integral fouling behavior of an apparatus. Modeling of this quantity is a permanent

Marangoni effect is one of the critical factors in the droplet evaporation process, which is caused by surface tension gradient in the droplet interface. In this study, local heating is adopted to provide a more complicated temperature distribution on the droplet surface, and a detailed numerical investigation is carried out to address the effect of Marangoni flow on the droplet evaporation behaviour

The thermal conductivity (TC) of rock has a general application in safety assessment and engineering optimization of deep geological engineering practices such as geothermal mining and nuclear waste disposal. Determining the TC of rock by using a TC model is a convenient and effective method for such evaluation, and selecting a suitable TC model is key for ensuring accurate calculation results. In

SAPO-34 and Y are two of the most commonly investigated zeolites for adsorption heat pump/cooling applications, due to their favorable adsorption properties. Some observations that mass transfer may be a limiting factor for SAPO-34 and faujasite (X/Y) coatings deserve further inquiry to understand better the performance limits of these materials. In this study, a theoretical investigation was made

R134a was recognized as probably one of the most important refrigerants of the two past decades. Among the proposed alternative fluids, there are certainly isobutane (R600a) and R152a. This article presents about 200 new heat transfer coefficient and pressure drop data obtained during flow boiling of R152a and R600a inside a smooth copper tube having an internal diameter of 4 mm. Three saturation temperatures

In this paper, a three dimensional Computational Fluid Dynamics Model (CFD) model was generated for spray cooling of straight parts by using a single point nozzle. The numerical simulations of spray quenching were performed to investigate the cooling rate of a 22MnB5 hot steel blank commonly used material in the automotive industry. Experiments are carried out to examine infrared thermograph of hot

Excellent ultra-thin heat pipes (UTHP) require a wick with high capillary force (ΔPc) and a good permeability performance (K). In this work, a copper powder-fiber composite wick was fabricated by sintering of the copper powder and fiber mixture. Effects of the copper powder particle size, copper powder volume ratio, as well as the super-hydrophilic treatment were investigated, and the results indicate

Jet impingement heat transfer finds applications where a large heat flux is required between a fluid and a surface. Impinging jets can be implemented in Concentrating Solar Power (CSP) thermal receivers and bayonet tube heat exchangers. A simultaneous outlook on the heat transfer and total pressure loss (performance) characteristics of several jets impinging on a concave hemispherical surface are investigated

The performance evaluation of radiator with the application of a new coolant, water-based of various shape nanoparticles i.e., spherical (CuO), cylindrical (CNT), platelet (Graphene) and vol. concentrations based ternary hybrid nanofluid have been investigated theoretically. Impact of heat transfer rate and pressure drop along with exergetic analysis on vol. fraction of ternary hybrid nanofluid, coolant

A parametric study is proposed in this paper to examine heat dissipation rate and entropy generation of a forced convection in a horizontal pipe which is filled with high porous metallic foams. The study quantifies the effect of thermal conductivity and pore density on entropy generation when the pipe is fully filled with copper, aluminium and nickel metallic foams of 0.6 m length in the fluid flow

Tomato (Solanum lycopersicum) and brinjal (Solanum melongena) are food products that are frequently wasted in Indian markets as their shelf lives are only a few days. An indirect type solar dryer (ITSD) has been developed. It’s performance and drying kinetics of brinjal and tomato slices have been analyzed. The moisture content of tomato decreased from 15.667 to 0.803 kg/kg of dry basis (db) and that

Pulsating heat pipe (PHP) is a two-phase heat transfer device, and the start-up characteristics plays a crucial role in its practical application and stable operating performance. This paper introduced the start-up principle of PHP and reviewed the influences of the cross-sectional shape, the physical property parameters and the external field action (i.e., magnetic field, ultrasonic wave etc.) on

It is important to study the temperature stratification phenomenon in flash evaporation to well design the marine accumulator and some related industrial equipment. Therefore, a series of flash evaporation experiments with initial temperature of 65.0 °C ~ 84.4 °C and superheat degree of 5.0 °C ~ 30.0 °C are carried out to study the temperature variations at different water depths. Meanwhile, the functional

Experimental results showed that the effective thermal conductivity of silicon nanowire is smaller than the bulk thermal conductivity, while that of carbon nanotube (CNT) is usually much larger than its bulk counterpart. In order to resolve this paradox, a nonlocal heat conduction model for one-dimensional materials is proposed. This nonlocal model indicates that the different heat conduction boundary

Natural convection heat transfer from vertical 9 × 9 rod bundle in liquid sodium was numerically analyzed to optimize the thermal-hydraulic design for the bundle geometry with equilateral square and triangle arrays (ESA and ETA). Unsteady laminar three-dimensional fundamental equations of natural convection heat transfer caused by step heat flux were solved numerically until the solution reached a

Indonesia is country that owns large enough source of geothermal energy. One effort can be done by utilizing geothermal energy as source for electrical energy generation. To produce a source of electrical energy using ORC using water (H2O) as a working fluid. In this research ORC system uses Refrigerant R-141b as a work fluid for water experiment (H2O) used at Rankine cycle at general. There are 4

In this study, experimental investigations and exergy analysis on shell and helically coiled tube heat exchanger are carried out for free convection heat transfer. The measured data are totally optimised utilizing thermodynamics rules in which exergy study is performed to investigate the thermal performance of the helical system under different operating conditions. The experimental set-up of apparatus

The present work deals mainly with dehydration characteristics of onion slices. Microwave power levels of 100, 350, 550 and 750 W was practiced to dry onion slices with thicknesses of 2.5, 5, 7.5 and 10 mm. The results showed that moisture diffusivity and specific energy consumption of the process increased with both increasing microwave power and the samples thickness, and ranged from 0.82 × 10−8

This paper investigates the total freezing time of droplets on surfaces with various wettabilities with horizontal and inclined orientations. A two-dimensional Volume of Fluid (VOF) method was applied to capture the liquid-air interface, and an automatic localized grid treatment technique was applied to increase the accuracy, especially near the impact and spreading areas. The Kistler and Shikhumurzaev

Thermochemical heat storage materials for space heating applications such as, ZnSO4 offer high energy storage density, low cost and clean mean of long-term solar energy storage. Herein, we studied the ZnSO4 hydrated salt as potential heat storage material at low temperature and furthermore observed the impact of temperature and concentration on the dehydration/hydration process and enthalpy. The thermal

In the present study, a series of experiments are conducted to investigate the thermal performance of a copper made pulsating heat pipe consisting of uniform flow passages with the cross section of 2 mm × 2 mm. Test conditions cover two orientations (0° and 90°) and six different filling ratios (10%, 25%, 40%, 55%, 70% and 85%). The working fluid used in the experiments is methanol. Heat inputs are

For further understanding the coal spontaneous combustion in goaf, the dynamic evolution of the oxygen concentration field influenced by the condition of negative pressure of cross-cut were analyzed. Based on the on-site testing results, the range of the oxidation zone on the headentry and tailentry side is determined as 30 ~ 75 m and 15 ~ 65 m respectively. This paper adopts a new method called “fixed