Abstract The objective of this work was to estimate parameters of a model for diode-laser heating of a culture of cancer cells under the effects of a chemotherapy drug. Two mathematical models were proposed to represent the physical problem during heating: natural convection was considered in the high-fidelity model, while the low-fidelity model was given by a lumped system. The thermal damage caused

Abstract We analyze numerically the influence nonuniform asymmetric heating on the forced convective conjugate heat transfer characteristics for two-dimensional, steady flow of Newtonian fluid through a parallel plate microchannel. A parametric study is carried out by varying the phase difference, amplitude and period of fluctuation of the imposed heat flux, thickness and thermal conductivity of the

Abstract In this article, transient response of triangular longitudinal fin with internal heat generation under step change in (i) base temperature and (ii) base heat flux assuming is reported. The convection coefficient is assumed to be power law function of temperature, accounting for different practical application. Moreover, thermal conductivity and heat generation coefficient are assumed as linear

Abstract The diverging microchannel has a gradually expanding cross-section area along the flow direction that can reduce flow instability and hence partial dry out. Utilizing the VOF method, Hardt and Wondra phase change model, and dynamic refined mesh scheme within a self-developed OpenFOAM solver, the vapor slug bubble’s growth inside diverging and uniform microchannels are investigated. The effects

Abstract The cooling of the turbine blade plays a vital role in increasing the durability and thermal efficiency of the turbine. Blade cooling is achieved by passing coolant through internal channels roughened with rib turbulators. In this work, the effect of rotation on heat transfer of a square ribbed duct is studied using Large Eddy Simulation (LES) at a Reynolds number based on the average bulk

Abstract The flow and heat transfer characteristics of gas-liquid Taylor flows in a horizontal tube with 3.12 mm inner diameter were studied numerically with the volume of fluid method. The bubbles are patched using the user defined functions based on the experimental volumes and formation frequencies. Numerical results agree well with the experimental results and empirical correlations. The results

Abstract Parabolic trough solar collector (PTSC) is an effective solar harvesting system that can be combined to various systems with different working fluids. This research presents a novel investigation on a PTSC system in which nanofluids are used to transfer heat energy. CFD analysis is performed according to FVM method to complement the study. Syltherm 800 oil is used as the main operating fluid

Abstract This investigation is aimed at the design and optimization of boron arsenide insert structures embedded in the heat spreader of a 3-D Integrated Circuit (IC). The inserts are distributed in three main configurations: radial, one level of pairing, and two levels of pairing. The considered heat spreader is constituted of a composite of copper and highly conductive blades made of boron arsenide

Abstract The two basic equations in the mentioned article are wrong.

Abstract The charging process of solar power applied leaf venation shape bionic latent heat thermal energy storage (LHTES) system was studied in the present research. n-Eicosane was chosen for the phase change materials (PCMs) and the enthalpy porosity method and Boussinesq approximation were applied. A series of transient three-dimensional models built by structure mesh were established to calculate

Abstract A comprehensive three-dimensional numerical model is developed to evaluate the effects of bending on the performance of both low temperature and high temperature heat pipes. The model solves for wall, wick, and vapor regions and includes the compressibility effects of the vapor. The proposed model can calculate the operating pressure and temperature of the heat pipe based on the operational

Abstract This article proposes a liquid-cooled battery thermal management system based on a serial-parallel mini-channel cold plate to solve the problem of severe heat generation during high-rate battery discharge. The numerical simulation method was used to investigate the cooling effects of the bottom margin of the inlet flow channel length (L) and flow channel width (W). The results showed that

Abstract In this work, a fourth-order compact finite difference (FD) algorithm on the nine-point 2-D stencil is proposed to simulate numerically natural convection in an inclined square enclosure using the vorticity-stream function form of the Naiver-Stokes equations. The key feature of the proposed algorithm is that for all Rayleigh numbers Ra of physical interest, the point-successive overrelaxation

Abstract In this study, the flow characteristics and heat transfer performance of rib channel installed with four types of multigap, 45°-angled rib turbulators on the top and bottom walls are numerically investigated using ANSYS Fluent version 19, and an optimal rib structure that facilitates enhanced heat transfer performance is determined. The analyzed structures are as follows: Case 1: inline-type

Abstract The primary purpose of the present study is to investigate the unsteady flow and heat transfer characteristics of non-Newtonian power-law fluid over an oscillating flat plate. The power-law fluid model is employed to distinguish the non-Newtonian fluid behavior, which has wide applications in nature and technology, such as crude oil exploitation, polymer processing and some bio applications

Abstract In the present study, a new optimization method called natural construction (NC) method was presented. This method was inspired by constructal law and it is an effort to extend this theorem by eliminating its predefined constraints. The proposed NC method was implemented on evolutionary optimization of embedded high conductive continuous strips in a cold plate to cool a uniformly heat-generating

Abstract The tool “Heatlines” is useful to understand heat flow and thermal management in enclosures experiencing convection. The heatline concept was first introduced by Bejan in the early 80’s. This article starts with the fundamental principles of heatlines or heat flow trajectories followed by a generalized governing equation for heatfunction (Π) applicable for fluid, nanofluid, or fluid-saturated

Abstract In this work, the interaction impacts of solid nanoparticles and magnetic force on the entropy generation rates for three-dimensional forced convection over an inclined step in the presence of Brownian movement are examined. To achieve this goal, analysis of the thermodynamics second law is used. The working fluids in this three-dimensional problem are the Al2O3–H2O and CuO–H2O nanofluids

Abstract This article applies computational fluid dynamics (CFD) to investigate the thermal and flow fields in the afterburner of solid oxide fuel cell (SOFC) systems. The objective is to estimate the performance of the burner to serve as a reference for performance improvement through structure design. The elliptical baffled burner, which enhances the effect of convective heat transfer and temperature

Abstract A new CFD modeling approach is developed and applied to a numerical study of pool boiling. It is based on a coupled simultaneous solving of the two-fluid model of two-phase flow in the boiling pool and the transient heat conduction within the heated wall. The applied two-fluid model consist in mass, momentum and energy balance equations for each phase and the closure laws for interface transport

Abstract The ambient air with the excessive moisture needs to be dehumidified for a comfortable environment using air conditioning. The planar membrane-based dehumidifier (PMD) is a potential technology to remove moisture in humid air. The performance of PMDs with different operating conditions is evaluated via numerical simulations with focuses on influences of the flow channel geometry, i.e. aspect

Abstract Numerical simulations of a symmetric array of inclined fins heat sink under natural convection had been carried out using the ANSYS icepak to solve the complete Navier-Stokes equation and the energy equation in the current study. The effects of fin height (20 mm ≤ H ≤ 40 mm) and heat sink installation angle (–45° ≤ φ ≤ 30°) were analyzed. The work fluid was the air. The results showed that

Abstract This work performs a direct simulation on forced convection heat transfer of flow past a square cylinder in a channel with an upstream promoter. The promoter is small in size that the incoming flow is stagnated and heated, thus the flow in the gap between the promoter and main cylinder keeps steady and the heating by the main cylinder gets weak as it develops downstream. The objective of the

Abstract The present investigation deals with numerical simulation of thermo-hydraulic transport characteristics of non-Newtonian fluid flowing through a wavy channel subjected to isothermal condition. The power-law constitutive model is adopted to illustrate the rheological behavior of fluid. The influence of various parameters like index of power-law (n), Reynolds number (Re), amplitude of sinusoidal

Abstract This article focuses on two major objectives. The first is the realization in the ANSYS Multiphysics 2017 software of numerical simulations of solar thermoelectric generators (STEG) equipped with vortex tube to supply the accessories of hybrid vehicles according to the solar flux, the vehicle speed and the adjustment of the fraction of cold air from the vortex tube. A comparative study between

Abstract For the sake of investigating the heat transfer performance and its mechanism in body-air-cloth microclimate system and studying the influence of inflow air property and environment conditions, numerical calculations are carried out using computational fluid dynamics method. It is found that the body-clothing microclimate is highly influenced by the heat transfer and air gap distance between

Abstract The primary purpose of the present study is to investigate the unsteady flow and heat transfer characteristics of non-Newtonian power-law fluid over an oscillating flat plate. The power-law fluid model is employed to characterize the non-Newtonian fluid behavior, which has wide applications in nature and technology, such as crude oil exploitation, polymer processing and some bio applications

Abstract This article conducts a two-dimensional numerical model to simulate the ferrofluid droplet formation from microfluidic T-junction under inhomogeneous magnetic fields with diverse strengths. This external magnetic field is produced by two electric straight wires in a finite computational domain. A coupled volume-of-fluid and level-set interface tracking method (VOSET) is adopted to capture

Abstract Numerical modeling based on volume of fluid (VOF) method is conducted and experimentally validated for the two-phase flow and heat transfer in a loop thermosyphon for wide filling ratios. The results show that, under the 87% filling ratio, the loop is dominated by bubbly flow and sub-cooled flow boiling, with sensible heat transfer enhanced by bubble pumping effect, which is beneficial for

Abstract High-porosity “cellular materials” are desirable for manufacturing multifunctional heat exchangers. While stochastic metal foams and regular strut-based topologies have been the focus of many prior investigations, there is very limited research on mathematically defined, triply-periodic minimal surfaces (TPMS). To this end, convective heat transport in sheet-based TPMS topologies, viz. gyroid

Abstract Analyzing the heat transfer effectiveness of fire suppression systems at droplet level through experimentation is difficult and costly. To overcome this issue, traditional Eulerian–Lagrangian model has been modified to track droplet histories in association with computational fluid dynamics (CFD) fluid models. This allows a comprehensive description of the flame interaction energy migration

Abstract The emission characteristics of non-premixed impinging flames are investigated using PIV experiments and numerical simulations. Different coflow conditions are conducted to focus on the pollutant emissions with the flame-wall interaction. Results show that flame dynamics obtained from experiments are in good agreement with that calculated from numerical simulations, and flame instability is

Abstract A novel alternating offset oblique microchannel (AOOMC) is proposed aimed at enhancing the thermal–hydraulic performance (THP) in microchannels. 3-D, conjugate numerical simulations are carried out over a range of Reynolds number from 200 to 800. The effect of three geometric parameters, relative oblique channel width (α), relative fin offset width (β), and oblique angle (θ), on THP is evaluated

Abstract In the present work, 3-D numerical simulations have been carried out to understand the flow patterns and heat transfer on the jacket side of a stirred vessel under mixed convection conditions. Various parameters have been varied (1 ≤ Uin ≤ 20 m/s, 30 ≤ ΔT ≤ 60 K, 30 ≤ Jg ≤ 150 mm, Di= 1 and 3 m) to understand their effect on the heat transfer and pressure drop on the jacket side. SST k-ω model

Abstract Processes that use moving point heat sources to temporarily create localized melt pools (metal additive manufacture and fusion welding) have a flow phenomenon due to the surface tension gradient. Surface tension of the liquid metal reduces with temperature and this, coupled with the high temperature gradients associated with point heat sources, creates Marangoni convection in the melt. The

Abstract Current work involves entropy generation studies within nine porous containers involving identical area for Prm = 155 (engine oil), Dam=10−5−10−2 at Ram=106. The entropy generation maps for lesser values of Dam depict that Sθ is dominant at the boundaries whereas Sψ is dominant at the central zone. On the other hand, for larger values of Dam, Sψ is found to be dominant throughout the porous

Abstract The asymmetric phenomenon of flame deflection in the combustion process of coal-fired boiler for different flow pattern, deflection angle and primary temperature were presented in this work. Numerical simulation was used for this paper to analyze the flow and heat transfer of the boiler furnace combustion. Air flow and combustion condition for the furnace firstly was simulated. And the nonlinear

Abstract In the present work, 3-D numerical simulations have been carried out to understand the flow patterns and heat transfer on the jacket side of a stirred vessel under mixed convection conditions. Various parameters have been varied (1 ≤ Uin ≤ 20 m/s, 30 ≤ ΔT ≤ 60 K, 30 ≤ Jg ≤ 150 mm, Di = 1 and 3 m) to understand their effect on the heat transfer and pressure drop on the jacket side. SST k-ω

Abstract This article conducts a two-dimensional numerical model to simulate the ferrofluid droplet formation from microfluidic T-junction under inhomogeneous magnetic fields with diverse strengths. This external magnetic field is produced by two electric straight wires in a finite computational domain. A coupled volume-of-fluid and level-set interface tracking method (VOSET) is adopted to capture

Abstract In this article, two model order reduction (MOR) methods of Krylov subspace and Laguerre orthogonal polynomials were employed to the numerical simulation of heat transfer characteristics of ground heat exchangers and surrounding ground. The results show that the relative errors between the direct solution and two MOR methods are less than 0.1% under more than certain orders. Considering both

Abstract A novel alternating offset oblique microchannel (AOOMC) is proposed aimed at enhancing the thermal–hydraulic performance (THP) in microchannels. 3-D, conjugate numerical simulations are carried out over a range of Reynolds number from 200 to 800. The effect of three geometric parameters, relative oblique channel width ( α ) , relative fin offset width ( β ) , and oblique angle ( θ ) , on THP

Abstract An attempt is made to improve the overall performances of channel heat exchangers. The techniques of baffles and nanofluids are combined to enhance the dynamic and thermal behaviors within the channel exchanger. Baffles under various attack angles are used as vortex generators. In addition, oil/multiwalled carbon nanotubes (MWCNT) is used as a working fluid. Both inclinations in the upstream

Abstract An attempt is made to improve the overall performances of channel heat exchangers. The techniques of baffles and nanofluids are combined to enhance the dynamic and thermal behaviors within the channel exchanger. Baffles under various attack angles are used as vortex generators. In addition, oil/multiwalled carbon nanotubes (MWCNT) is used as a working fluid. Both inclinations in the upstream

Abstract This numerical study performed the three-dimensional simulations to explore the turbulent thermal flow characteristics over the heated blocks inside a square channel by a slotted ribbed plate through the RNG κ − ε turbulence model and SIMPLE-C algorithm. The influence of slotted ribbed plate on the enhancement of turbulent heat transfer from these heated block surfaces would be evaluated through

This numerical study performed the three-dimensional simulations to explore the turbulent thermal flow characteristics over the heated blocks inside a square channel by a slotted ribbed plate throu...

Abstract Dropwise condensation on rough surfaces enhanced with pillars in the presence of non-condensable gas (NCG) including the initial nucleation process is simulated using the multispecies multiphase lattice Boltzmann method, and the effect of mass fraction of NCG, the surface wettability, the bottom wall temperature and the geometrical parameter (the pillar height H) on condensation process are

A comprehensive numerical study is performed on a vertical hollow cylinder of finite thickness for natural convection with surface radiation effect. The prime aim is to find out the heat transfer r...

Thermal analysis of heat-generating battery pack cooled by several coolants is analyzed numerically. The coolant used are gases, oils, thermal oils, nanofluids, and liquid metals to find the best c...

Abstract A two-dimensional model is proposed for energy efficiency assessment through the simulation of heat transfer in building envelopes, considering the influence of the surrounding environment. The model is based on the Du Fort–Frankel approach that provides an explicit scheme with a relaxed stability condition. The model is first validated using an analytical solution and then compared to three

Abstract In this study, numerical simulations of the interaction between supersonic crossflow and a side liquid jet were performed. The processes of the liquid jet breakup, flow separation and shock waves resulting from the interaction of the gas flows and liquid droplets were predicted. In the numerical simulation, a two-way coupling Eulerian-Lagrangian method was used. The two-dimensional unsteady

In this study, numerical simulations of the interaction between supersonic crossflow and a side liquid jet were performed. The processes of the liquid jet breakup, flow separation and shock waves r...

In this study, turbulent flows and the associated mixing characteristics are numerically investigated for noncircular jets. The selected nozzle shapes are round, square, and equilateral triangular,...

Abstract The present study investigates the performance of selected turbulence models to predict the temperature distribution and eddy viscosity ratio in a horizontal direct-chill casting. The turbulence models include the velocity variance–elliptic relaxation ( ), the kinetic energy-specific dissipation rate shear stress transport (k-ω SST), standard kinetic energy dissipation rate (k-ε), and its

Abstract Water management is crucial to the performance of proton exchange membrane fuel cells (PEMFC). In this work, a pore-scale model is developed based on lattice Boltzmann (LB) method for the simulation of multicomponent multiphase reactive transport in an operating PEMFC, with the aim to capture the water vapor generation, condensation, and subsequent transport in the entire porous cathode, including

Abstract The present study numerically examines the impact of zigzag fin surface pattern structures in a micro-channel heat exchanger on heat transfer efficiency using a commercial computational fluid dynamics program. The three newly designed louvered fin structures that comprise four triangular zigzag patterns, alternately spaced structures on both fin sides, a flat or zigzag fin structure on either

Abstract To reasonably select the process parameters of the double cone specimen (DCS) during hot compression, the temperature field evolution in the resistant furnace during the heating stage of hot compression was analyzed by numerical and experimental methods. The results show that there is a significant temperature gradient between surface and center of the specimen during the heating stage, the

(2020). Correction. Numerical Heat Transfer, Part A: Applications: Vol. 78, No. 11, pp. I-I.

Abstract The structural optimization of a specific laminated cooling structure is conducted under gas turbine combustor representative aero-thermal conditions, with the aim at improving its overall cooling effectiveness. The optimization procedure is realized by using conjugate heat transfer CFD analysis and radial basis function neural network (RBFNN) surrogated model. For this specific laminated

Abstract In this work, a fast and efficiently design method has been introduced. This design process consists of the overall design and the detailed design. For the overall design, one-dimensional pipe-network computations are employed to obtain several design cases quickly at the beginning. Meanwhile the solid domain geometry and mesh with cooling structures, i.e., film holes, impingement holes, and

Abstract Biomimetics is the imitation of the systems, models, and nature elements for the motive of elucidating complex biological problems. In the current century, the use of nanoparticles in the treatment of biological systems (such as cancer and atherosclerosis treatment) is common in worldwide due to many properties of nanoparticles. In general, the size of nanoparticles are very small so that