bluuebunny/crossref_metadata_2025_split huggingface dataset:
A numerical method based on domain decomposition to solve coupled conduction-radiation physics using parallel computing within large porous media
Authors: Kumar Atin , Vicente Jérôme , Daurelle Jean-Vincent , Favennec Yann , Rousseau Benoit 
Published: December 2021

Abstract
A domain decomposition approach is developed to solve coupled conductive– radiative heat transfer within highly porous materials. In this work, a Kelvin–cell foam with five cells in each direction which has ˇ15.6 × 106 of voxels is considered. The coupled heat transfer is solved using the finite volume method where deterministic ray tracing is used to calculate radiative exchange. The temperature distribution is computed and cross–validated with the distribution obtained using a commercial software STAR–CCM+.
Experimental thermal performance comparison of pure and metal foam-loaded PCMs
Authors: Silvestrini M , Falcone M , Salvi F , Naldi C , Dongellini M , Morini GL 
Published: December 2021

Abstract
The thermal performance of latent heat thermal energy storage (LHTES) systems considerably depends on thermal conductivity of adopted phase change materials (PCMs). To increase the low thermal conductivity of these materials, pure PCMs can be loaded with metal foams. In this study, the melting process of pure and metal-foam loaded phase change materials placed in a rectangular shape case is experimentally investigated by imposing a constant heat flux at the top. Two different paraffin waxes with melting point of about 35°C are tested. The results obtained with pure PCM are compared with those achieved from the use of PCM combined with two different porous metals: a 10 PPI aluminum foam with 96% porosity and a 20 PPI copper foam with 95% porosity. The results demonstrate how metal foams lead to a significant improvement of conduction heat transfer reducing significantly the melting time and the temperature difference between the heater and PCM.
An estimate of size of copper nanoparticles levitating over the melt surface using the measurements of spectral reflectance
Authors: Dombrovsky Leonid A , Mendeleyev Vladimir Ya 
Published: December 2021

Abstract
A strong decrease in normal reflectance of a probe laser beam of 660 nm wavelength reflected from the surface of copper sample just after the beginning of the sample melting in a rarefied argon atmosphere has been observed recently by the authors. A similar time dependence of the reflectance is obtained in the laboratory experiments of the present paper at the wavelengths of 532 nm. The additional spectral measurements enable the authors to estimate the size of condensed nanoparticles levitating over the copper melt.
Numerical simulation of coupled diffuse radiation and natural convection in a cubic cavity heated from bottom
Authors: Chanakya Ganaparthi , Kumar Pradeep 
Published: December 2021

Abstract
We present, a three-dimensional numerical simulation of coupled natural convection with diffuse radiation in a cubic cavity whose all four vertical walls are isothermal, the bottom wall is convectively heated and the top wall is insulated. All walls are treated as black, diffuse and opaque for radiation. The simulations are carried out for the fixed Rayleigh (Ra=105) and Prandtl numbers (Pr=0.71) for a transparent and participating medium. The flow visualization technique Q-criteria has been used for analysis of the flow structure. The isothermal surfaces inside the cavity form vertical co-axially convergent-divergent three-dimensional open and closed nozzles, while inside the cavity Q-criteria reveals the formation of Jellyfish like flow structure. The cavity contains four conical vortices whereas each vortex is occupied in tetrahedron space.
Analysis of damaged Alumina Enhanced Thermal Barrier
Authors: Brodzik Ł 
Published: December 2021

Abstract
The paper presents the problem of aerodynamic heating of a damaged Alumina Enhanced Thermal Barrier AETB. At the given minimum dimensions of the cover layers, the impact of damage size on the temperature increase on the skin surface was analyzed. The aim of the study was to determine the temperature curve as a function of the size of damage. In the calculations FreeFem ++ non-commercial environment was used.
Radiative heat transfer calculation for mixture of gases using full spectrum k-distribution method
Authors: Khemani Kamal , Kumar Pradeep 
Published: December 2021

Abstract
The full spectrum k-distribution method is used to obtain radiative heat flux and divergence of radiative heat flux for two test cases, containing mixture of CO
2 and H
2
O at different concentration and temperature keeping pressure constant. The k-distribution for mixture of gases is obtained from individual gas k-distribution using three different mixing models, viz., superposition, multiplication and hybrid model. Further, the radiative transfer equation (RTE) is solved by the finite volume discrete ordinate method (FVDOM) to obtain the radiative flux and the radiation source term. The results obtained were compared with the FSK from spectral addition and LBL method. The multiplication mixing model provides better accuracy compared to other mixing models considered in the present study.
Evaluation of stability and viscosity of [C2mim][DCA] based ionanocolloids
Authors: Pinto J , Fabre E , Murshed S M S 
Published: December 2021

Abstract
In the search for the optimization of heat transfer systems, Ionanocolloids (INCs) as we have termed here, have revealed as very attractive choices due to their increasingly potential applications in thermal energy areas. By definition, INCs are suspensions of nanoparticles (NPs) into Ionic Liquids (ILs). Besides a high degree of versatility and enhanced thermal properties, these new class of fluids are considered as green solvents due to their negligible vapor pressure, non-flammability and recyclability. Despite the great advantages of using these INCs, their industrial application is still a challenge due to low stability and high viscosity issues attributed to them. In this work, different Ionanocolloids were prepared by two-step method, using 1-ethyl-3-methylimidazolium dicyanamide ([C2mim][DCA]) together with deionized water as base fluids and 3 different NPs: Titanium(IV) Oxide, Silicon Oxide and Aluminum Oxide. The stability and viscosity of these mixtures were then evaluated and the results are reported.
Two-phase flow model of a horizontal symmetrical impacting T-junction
Authors: Van Heule X , Van Nieuwenhuyse J , De Paepe M , Lecompte S 
Published: December 2021

Abstract
A symmetrical distribution of the two-phase refrigerant mixture before the evaporator is crucial to achieve optimal performance of heat pumps. In a previous study experiments on two-phase flow in a horizontal symmetric impacting T-junction were conducted in our lab. The measurements performed include both pressure drop and phase distribution data of refrigerants. This data is unique as almost all previous experiments in literature investigate air-water flows. With this data a mechanistic model was constructed which is capable of predicting the phase distributions and pressure drop depending on the flow regime and the fluid properties. The model is capable of predicting 90% of the data with a maximum mean deviation of 5%.
3D gas-liquid interfaces and flow characteristics of two-phase flows in horizontal tubes
Authors: Zhang Jingzhi , Sunden Bengt , Wadekar Vishwas , Wu Zan 
Published: December 2021

Abstract
In order to investigate the characteristics of gas-liquid two-phase flows in horizontal mini circular tubes with inner diameters of 3.14 and 6.68 mm, a prism is adopted to improve the light path in the visualization experimental setup. The front and top views of air-water two-phase flow patterns in two tubes are captured synchronously based on the improved method. Three-dimensional gas-liquid interfaces, flow pattern maps, and void fraction are obtained. The experimental results show that tube diameters have significant effects on flow patterns transition lines in the flow pattern maps, but the void fractions are independent on channel sizes. The effect of gravity gradually decreases with decreasing tube diameter, while that of surface tension is enhanced. As a consequence, the proportion of annular flow in flow pattern map increases in mini tubes, while the reverse is true for the stratified flow whose proportion decreases dramatically in mini channels. The void fraction increases with increasing gas quality. Experimental void fractions obtained using the three-dimensional gas-liquid interfaces fit well with correlations in the open literature. The shape of PDF distributions varies with flow patterns, which could be used to identify flow patterns in industrial applications.
Digital holographic study of vapor transport of heavy hydrocarbon from heated well cavity
Authors: Shukla Digvijay , Panigrahi Pradipta Kumar 
Published: December 2021

Abstract
Thin film evaporative cooling is one of the liquid cooling technologies, capable of removing high heat flux with lower junction temperature due to the utilization of latent heat of vaporization. To understand the various transport processes involved in vapour phase during thin film evaporation, evaporation from a heated well cavity of diameter 3 mm and height 2 mm is studied using Digital holographic interferometry technique. A flat disk-shaped vapour cloud is appeared for heated as well as not- heated well surface case. This signifies radial outward natural convection instead of pure diffusion. A higher vapour concentration is obtained at each time instants for heated surface case due to the higher evaporation rate as compared to non-heated, ambient case.
Averaged energy-balance analysis of wavy micro-channels
Authors: Durantes Roxana , Moon Justin , Rafael Pacheco J , Pacheco-Vega Arturo 
Published: December 2021

Abstract
This study presents numerical simulations of the convective heat transfer on wavy micro-channels to investigate heat transfer enhancement in these systems. The goal is to extend the analysis of our previous work [1, 2], by proposing a methodology based on local and global energy balances in the device instead of the commonly used Nusselt number. The analysis is performed on a single-wave baseline micro-channel model that is exposed to a heat influx. The governing equations for an incompressible laminar flow and conjugate heat transfer are first built, and then solved, for representative models, under several operating conditions, by the finite element technique. From computed velocity, pressure and temperature fields, local and global energy balances based on cross-section-averaged velocities and temperatures enable calculating the heat rate at each section. Results from this study show that this so-called averaged energy-balance methodology enables an accurate assessment of the channel performance.
Room temperature Magneto-Caloric Refrigerator: system level analysis
Authors: Rajamani Keerthivasan , Der Meer Theo Van , Shahi Mina 
Published: December 2021

Abstract
A system consisting of magneto-caloric fluid, which releases (absorbs) heat in the presence (absence) of a magnetic field, is used to achieve refrigeration. Gadolinium is used as a magneto-caloric material. The influence of using water and galinstan as heat transfer liquid, on the refrigerator performance is numerically analysed by varying the mass flow rate of the magneto-caloric fluid, and MCM volume fraction (0.4 to 0.6). A cooling load upto 20 W at room temperature is obtained over a temperature difference of 0.5 K.
Experimental study of the thermal management process at low-temperature circulating charging of an adsorbed natural gas storage system
Authors: Chugaev Sergey , Strizhenov Evgeny , Men’shchikov Ilya , Shkolin Andrey 
Published: December 2021

Abstract
Adsorbed natural gas (ANG) technology is a promising alternative to traditional compressed (CNG) and liquefied (LNG) natural gas systems. Nevertheless, energy efficiency and storage capacity of ANG system strongly depends on thermal management of its inner volume because of significant heat effects occurring during adsorption/desorption processes. At the same time low-temperature charging of ANG system provides its higher storage capacity as well as increased fire and explosion safety due to lower operating pressure and “bound-state” of gas molecules with the surface of adsorbent. In present work, a prototype of low-temperature circulating charging system for ANG storage tank filled with shaped microporous carbon adsorbent was studied experimentally in wide ranges of pressures (0.5-3.5 MPa) and gas flow rates (8-18 m3/h).
Experimental study of heat transfer in adsorbed natural gas storage system filled with microporous monolithic active carbon
Authors: Strizhenov Evgeny , Chugaev Sergey , Men’shchikov Ilya , Shkolin Andrey , Shelyakin Igor 
Published: December 2021

Abstract
The study of the thermal state of the monolithic adsorbent layer and internal heat exchange processes during the circulating charging of an adsorbed natural gas storage system was carried out. The correlation between gas flow mode and the heat transfer coefficient between gas and adsorbent is determined under conditions of mass transfer.
Advanced Adiabatic Compressed Air Energy Storage design and modelling accounting for turbomachinery performance
Authors: Roncolato J , Zanganeh G , Jenny P , Scholtysik M , Jacquemoud E , Haselbacher A , Barbato M C 
Published: December 2021

Abstract
Energy storage plants are going to become a strategic asset in electric grids. This statement is confirmed looking at the increasing shares of renewables composing the energy portfolio of several nations. Therefore the power demand and production mismatches, caused by the intermittent nature of renewables, must be reconciled. Many energy storage solutions are available but Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) plants have potentials similar to pumped hydro systems (PHS). A physical model was developed in Matlab-Simscape to simulate the dynamics of AA-CAES plants, implementing temperature-dependent air properties, efficiency maps for turbomachinery and realistic power ramps. Furthermore, start-up and shut-down phases and energy consumption during idle periods were accounted for. The model embeds a 1D Fortran code to model the detailed behaviour of a packed-bed TES. The grid-to-grid performance of an AA-CAES plant was determined and the assumptions implemented to take into account real turbomachinery behaviour are presented.
Passive system of cooling and refrigerant fluid circulation, assisted by capillary pumping
Authors: Sologubenko O , Hemrle J , Kaufmann L 
Published: December 2021

Abstract
We propose a concept design of a cooling system, primarily targeting gas-insulated switchgear enclosures which use a mixture of a refrigerant fluid, such as Novec™ 649, and a non-condensable gas for electrical insulation. The novel open-loop system relies on evaporative cooling assisted by capillary pumping, and refrigerant vapor condensation on the walls of the system enclosure. The results of experiments on a laboratory prototype are presented and discussed. Besides cooling, a major benefit of the system is in facilitating the circulation of the gas mixture in the enclosure.
Inorganic PCMs applications in passive cooling of buildings - A review
Authors: Adeel Hassan Hafiz Muhammad , Lund Ivar 
Published: December 2021

Abstract
Buildings consume around 40% of total world energy and are responsible for 30-35% greenhouse gas emissions globally. Latent heat thermal energy storage is one of the most promising techniques being investigated currently to reduce the thermal load of buildings. Different types of phase change materials (PCMs) i.e. organic, inorganic and eutectics with different thermophysical properties have been investigated for passive cooling of buildings showing great potential for saving energy. Due to their higher thermal conductivity and high heat storage capacity per unit volume, inorganic phase change materials take advantage over organic ones. They can be used as stand-alone heat storage systems for free cooling, embedded in building walls, windows, roofs and ceilings etc. Studies have shown that there are some drawbacks of inorganic PCMs as well like corrosion of container material, phase separation and supercooling which require solutions.
Performance analysis of a new system for night cooling of buildings on a full scale office room - CFD study
Authors: Lança M , Coelho P J , Viegas J 
Published: December 2021

Abstract
Night natural ventilation systems have been receiving increased attention in recent years because of their energy saving potential and environmental protection when used in passive instead of active cooling. A recently proposed novel system for cooling the building concrete slab is studied numerically in the present work. It consists of a new type of a Suspended Ceiling (SC) with a peripheral gap between it and the walls, combined with the positioning of the air supply and extraction grilles between the ceiling slab and the SC. The system relies only on night ventilation as a means for cooling down the structure of the building. This study focuses on the use of Computational Fluid Dynamics (CFD) to predict the airflow and thermal performance of this strategy and it is applied to a full scale office room. The calculations show that a SC with a gap can reduce the difference between the average temperatures at the end of the heating and the end of the cooling periods by 25% compared with the case of a full covered slab room scenario (tight SC). CFD proved to be a useful and accurate tool to predict indoor conditions in buildings.
Validation and calibration of dynamic energy models: energy audit of a public building
Authors: Bergero S. , Chiari A. 
Published: December 2021

Abstract
Detailed buildings energy audits require dynamic simulation models based on hourly input data. This paper presents the calibration and validation of an office building energy model for the heating and cooling services. Simulation are carried out by DesignBuilder software. Measured hourly heating and cooling energy supplied by the generation system are used for the calibration of the model. Employee behaviour with reference to occupancy profiles and indoor temperature settings is also considered. A good agreement between measured and simulated data is obtained for both heating and cooling seasons.
Estimation of local heat flux for turbulent flow in a helical coil tube by conjugate gradient method
Authors: Shah S , Parwani A K 
Published: December 2021

Abstract
Estimation of local heat flux is challenging in a helical coil tube heat exchanger due to the complex flow field developed by tube curvature. The heat flux has uneven distribution in the angular direction of the tube cross-section. The current research aims to estimate the local heat flux at the fluid-solid interface for the turbulent flow of water in a helical coil tube by solving the inverse heat conduction problem (IHCP). Conjugate gradient method (CGM) with an adjoint problem is used as an inverse algorithm. First, the commercial CFD software ANSYS FLUENT is used for solving the governing equations of continuity, momentum, and energy for turbulent flow to obtain the heat flux at the fluid-solid interface. This heat flux is used to determine the temperature distribution at the outer surface of the tube. The heat flux is then considered unknown and it is estimated by CGM algorithm with the developed in-house code in MATLAB. The result shows that the estimation of heat flux by CGM is very accurate.
Experimental analysis of the evaporation of a thin liquid film deposited on a capillary heated tube: estimation of the local heat transfer coefficient
Authors: Cattani L , Bozzoli F , Ayel V , Romestant C , Bertin Y 
Published: December 2021

AbstractThe aim of this work is to estimate the local heat flux and heat transfer coefficient for the case of evaporation of thin liquid film deposited on capillary heated channel: it plays a fundamental role in the two-phase heat transfer processes inside mini-channels. In the present analysis it is investigated a semi-infinite slug flow (one liquid slug followed by one single vapour bubble) in a heated capillary copper tube. The estimation procedure here adopted is based on the solution of the inverse heat conduction problem within the wall domain adopting, as input data, the temperature field on the external tube wall acquired by means of infrared thermography.
Numerical optimization of a multistage sorption compressor
Authors: Hamersztein A , Davidesko A , Tzabar N 
Published: December 2021

Abstract
Sorption compressors are driven by thermal cycles and have no moving parts, excluding some passive check valves. Such compressors are suitable for powering Joule-Thomson (JT) cryocoolers and can provide reliable and vibration free active cooling system with a potential for high reliability and long operating life. The thermal cycle consists of cooling and heating a sorbent material which is installed in a sorption cell, where the heating is obtained by an inner electric heater and cooling is obtained by the surrounding via the sorption cell envelope. The investigation and optimization of the sorption cells were conducted in previous work, at steady state conditions, by a one-dimensional heat and mass transfer numerical model. The current paper presents a dynamic numerical model of sorption compressors which consist of several sorption cells. The numerical model allows one to three compression stages, with any number of sorption cells at each stage. The model enables the investigation of dimensional parameters and operational parameters, and provides the low and high pressures, pressure fluctuations, and compressor’s efficiency. The current investigation focuses on a three-stage compressor for nitrogen, with low and high pressures of 0.2 and 8 MPa, respectively, and a mass flow rate of about 11 mg/s.