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Publications related to Thermofluid (949)
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Article
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In this study, the energy charging mechanism is mathematically modeled to determine the impact of design modifications on the thermofluidic behavior of a phase change material (PCM) filled in a triplex tube containment geometry. The surface area of the middle tube, where the PCM is placed, is supported by single or multi-internal frustum tubes in v...
Article
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This paper presents a concurrent topology optimization approach to design multi-scale fluid channels, inlets, and outlets for efficient cooling capabilities. An approximate but low-cost thermofluidic model is used to predict the temperature distributions, in which the Darcy model is utilized to simulate the fluid flow. A novel boundary-based penalt...
Chapter
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The research community agrees that the main indirect way the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads among people who do not keep social distance is through the emission of infected respiratory droplets. Infected people exhale droplets of different sizes and emission velocities while breathing, talking, sneezing, or cou...
Article
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Fluids containing colloidal suspensions of nanometer-sized particles (nanofluids) have been extensively investigated in recent decades with promising results. Driven by the increase in the thermal conductivity of these new thermofluids, this topic has been growing in order to improve the thermal capacity of a series of applications in the thermal a...
Article
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Among the techniques offered to improve the efficiency of heat exchangers, the Dimpled surfaces were repeatedly reported as an applicable solution. In this regard, the current study is formed to evaluate the thermofluidic performance of Dimpled-Protruded tubes while following four novel investigations. Firstly, the impact of Protrusions next to the...
Article
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Boron nitride nanosheets (BNNS) were recently synthesized in a powder form using inductively coupled plasma through two readily-scalable bottom-up routes: (i) heterogeneous nucleation using amorphous boron particles and nitrogen, (ii) homogeneous nucleation from ammonia borane and nitrogen. The operating pressure was found to play a significant rol...
Article
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Characteristics of ignition process of polymer‐ablated arc with different current values were investigated with electromagnetic thermofluid analysis. This thermofluid simulation is based on calculated particle composition, thermodynamic and transport properties of evaporated vapor of polymer material and electrode material. Polymer ablation was ass...
Article
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The regenerator is one of the most important elements of a thermal machine operating in an alternating flow regime. The present study constituted an experiment on the dynamic characterization of different metallic regenerators crossed by alternating air flow. During an experiment, gas temperature, velocity, and pressure were measured at both ends o...
Conference Paper
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Metal additive manufacturing using Laser-Powder Bed Fusion (L-PBF) technique has enabled the metal manufacturing industry to use design tools with increased flexibility such as freeform internal channel geometries that benefit thermofluidic applications such as heat exchangers. A primary drawback of the L-PBF process is the as-built surface roughne...
Article
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Introduction/purpose: Researchers of fluids for high voltage engineering application always experience problems when selecting and recommending specific fluids suitable for high voltage application. This is due to the dual functionality of fluids required for high voltage equipment. Methods: This study introduced and employed a probability-based mu...
Article
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Manuscript Number: IJTF-D-21-00145R1 Cartesian Graetz problem with boundary condition of the third kind: A semi-analytical solution Marco Rosales Dear Dr Belhocine, Thank you for reviewing the above referenced manuscript. I greatly appreciate your contribution and time, which not only assisted me in reaching my decision, but also enables the a...
Article
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The design and techno-economic performance of a compact additively manufactured (AM) molten salt (MS)-to-supercritical carbon di-oxide (sCO2) primary heat exchanger (PHE) for solar thermal application is described. The PHE design consists of sCO2 flow through an array of microscale pin fins while the MS flows through mm-scale rectangular channels....
Article
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In the current investigation, the twisted tape inserts are considered as the augmentation thermal technique, the influence of a variety of twisted tape configurations on pressure drop characteristics, temperature differences, thermal performance of fluid flow structure, heat transfer improvement, and friction factor are numerically evaluated. The c...
Article
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We present a surface-engineering approach that turns all liquids highly wetting, including ultra-high surface tension fluids such as mercury. Previously, highly wetting behavior was only possible for intrinsically wetting liquid/material combinations through surface roughening to enable the so-called Wenzel and hemiwicking states, in which liquid f...
Article
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A 3D stationary particle tracking velocimetry (SPTV) with a unique recursive corrective algorithm has been successfully established to detect the instantaneous regional fluid flow characteristics. The veracity of SPTV is corroborated by conducting actual displacement measurement validation, which gives a maximum percentage deviation of about 0.8%....
Article
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This paper describes the findings of a numerical and experimental study on the heat transfer coefficient and pressure drop in micro-lattice blocks fabricated by selective laser metal melting and subjected to forced air convection. In particular, the influence of the unit-cell topology on the thermofluid performance of the lattice structure is exami...
Article
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Manuscript Number: IJTF-D-21-00145 Cartesian Graetz problem with boundary condition of the third kind: A semi-analytical solution Marco Rosales Dear Dr Belhocine, Thank you for reviewing the above referenced manuscript. I greatly appreciate your contribution and time, which not only assisted me in reaching my decision, but also enables the aut...
Article
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With the increasing thermal challenges of electronic equipment, topology optimization of heat sinks has aroused great research interest in recent years. However, most related researches deal with heat transfer problems of the laminar flow. Only several papers deal with heat transfer problems of the turbulent flow which exhibits better heat dissipat...
Conference Paper
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Moisture carried with the geothermal steam at the turbine inlet can cause millions of dollars lost in electricity generation. These revenue losses occur due to frequent power plant overhauls, retrofitting and extended turbine maintenance required to remove the scaling out of the turbine blades and diaphragm or replace expensive turbine components (...
Article
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Climatic chambers are highly important in research and industrial applications and are used to examine manufactured samples, specimens, or components in controlled environment conditions. Despite the growing industrial demand for climatic chambers, only a few published studies have specifically concentrated on performance analysis and functional im...
Article
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This study experimentally explores the thermofluidic performance of a cryogenic micro-pin fin cooler with two-phase liquid nitrogen flows. The liquid nitrogen cooling system is introduced to investigate the performance of the micro-pin cooler in a cryogenic condition. The result reveals that the nominal value of the base heat transfer coefficients...
Article
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Condensation is ubiquitous in nature and industry. Heterogeneous condensation on surfaces is typified by the continuous cycle of droplet nucleation, growth, and departure. Central to the mechanistic understanding of the thermofluidic processes governing condensation is the rapid and high‐fidelity extraction of interpretable physical descriptors fro...
Conference Paper
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This paper introduces the DLR Thermofluid Stream Li-brary: a free open-source library for the robust modelingof complex thermofluid architectures. Designed to be easyto use, easy to adapt and enriched by a number of exam-ples, this library contains the fundamental components formany different applications such as thermal managementof electric cars,...
Article
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In this paper, we present the physical foundations and the development of the thermodynamic part of a Modelica library with the fundamental components for modeling thermofluid systems. We have chosen Modelica because it is an object-oriented modeling language that allows an elegant design of the library, with a top-down conception that starts from...
Preprint
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A low-cost lumped parameter model (LPM) is developed to simulate hydrogen storage in solid-state materials. The proposed LPM is a zero-dimensional model based on an analogous transient thermal resistance network that considers the whole storage system as a resistor-capacitor (RC) circuit with a current source. Combined with the mass conservation, s...
Article
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The paper examines radiative Casson boundary layer flow over an exponentially shrinking permeable sheet in a Cattaneo–Christov heat flux environment. The sheet is placed at the bottom of the fluid‐saturated porous medium and suction is applied normally to the sheet to contain the vorticity. The radiative heat flux in the energy equation is assumed...
Article
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This paper presents experimental results on the study of the efects of ejector adiabatic absorber on heat and mass transfer of binary nanofuid with heat transfer additives (2-ethyl-1-hexanol and gum Arabic). In this case, H2O/lithium bromide-alumina nanofuid was suggested due to a growing interest in absorption heat transfer working fuid for sola...
Article
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Thermal management is one of the main challenges in the most demanding detector technologies and for the future of microelectronics. Microfluidic cooling has been proposed as a fully integrated solution to the heat dissipation problem in modern high-power microelectronics. Traditional manufacturing of silicon-based microfluidic devices involves adv...
Conference Paper
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Supercritical carbon dioxide (sCO2) power cycles have been identified as an attractive technology to reduce capital and operating expenditure of concentrated solar power (CSP) plants. Numerous studies have investigated various layouts and operating parameters at the system-level in search of an optimal cycle configuration. Two cycle layouts in part...
Preprint
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We provide an ab-initio scaling analysis for liquid film thickness and Nusselt number of a steady laminar jet impacting a rotating heated plate. The limiting scaling regimes incorporating the evaporative effects along the liquid-vapor interface have been probed. The dependence of liquid film thickness and Nusselt number on Reynolds, Rossby, and Pra...
Article
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This paper presents a surrogate- and possibility-based design optimization (SPBDO) methodology for robust design of convective PCR. Parametric computational fluid dynamics (CFD) models are built and simulated at sampled locations within the design space to capture the effect of design configurations on thermofluidic transport and convection–diffusi...
Article
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Predictions made by climate researchers are highly worrisome and demand rapid action to avoid the threat of climate catastrophe. Global energy systems must be transformed as quickly as possible by minimising or avoiding net greenhouse gas emissions. There is broad agreement on this goal, demonstrated by international treaties such as the Sustainabl...
Article
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This paper describes effects of intermittent Ar/CH4 quenching gas (QG) injection on the size and composition of Si/C nanoparticles synthesized using pulse-modulated induction thermal plasma (PMITP). Time-controlled feeding of feedstock (TCFF), with synchronous and intermittent injection of silicon feedstock powder to the PMITP, was used for high-ra...
Article
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This paper presents an analysis of the entropy generated in thermofluidic configuration involving micropolar couple stress fluid flow inside a Forchheimer channel. The channel is composed of a porous medium trapped between two parallel permeable plates separated by distance H through which the fluid can be sucked out/injected in. One of the plate b...
Article
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This paper investigates the topology optimization of planar cooling channels using a low-cost multilayer thermofluid model. A novel three-layer model including the upper/lower cover-plate layers and the central solid-fluid mixing layer is proposed. The flow boundary layer effect and the heat transfer effect in the thickness direction are modeled as...
Article
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Carbon dioxide (CO2, R744) is a natural working fluid with interesting thermophysical properties that have stimulated strong attention by the academic and industrial communities for a broad range of energy applications. The technology readiness level of CO2-based energy systems is very diverse due to the increasing consideration that the fluid has...
Article
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Individual technical components are usually well optimized. However, the design process of entire technical systems, especially in its early stages, is still dominated by human intuition and the practical experience of engineers. In this context, our vision is the widespread availability of software tools to support the human-driven design process...
Preprint
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The prohibitive cost and low fidelity of experimental data in industry-scale thermofluid systems limit the usefulness of pure data-driven machine learning methods. Physics-informed neural networks (PINN) strive to overcome this by embedding the physics equations in the construction of the neural network loss function. In the present paper, the mixe...
Article
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In this study, heat transfer in a tall, rectangular permeable cavity with active thermal walls is investigated. Inside the enclosure, the two side walls' central portions are partially cooled at a fixed temperature. The central portion of the footwall is heated. Additionally, the top wall, the remaining portion of the footwall, and the side walls a...
Article
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A computational study for investigating the flow and heat transfer phenomena in the unsteady magnetohydrodynamic couple stress dusty fluid flow over a linearly stretching porous surface in the presence of viscous dissipation effects is presented. The governing equations, in nondimensional form, are tackled by the exploitation of the standard spectr...
Preprint
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This study investigates the thermal-hydraulic characteristics of immiscible two-phase flow (gas/liquid) and heat transfer through porous media. This research topic is interested among others in trickle bed reactors, the reservoirs production of oil, and the science of the earth. Characteristics of two-phase concurrent flow with heat transfer throug...
Article
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A data-driven surrogate model is proposed for a 64-cell air-cooled condenser system at a power plant. The surrogate model was developed using thermofluid simulation data from an existing detailed 1-D thermofluid network simulation model. The thermofluid network model requires a minimum of 20 minutes to solve for a single set of inputs. With operati...
Article
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In this paper, numerical calculations were made for Ar loop-type inductively coupled thermal plasma (loop-ICTP). The loop-ICTP was developed originally by the authors’ group for rapid surface modification of large areas. Loop-ICTP is sustained with a unique three-dimensional (3D) configuration inside a circular loop quartz tube and on the substrate...
Article
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In this paper, we present a new model design and parametric studies of a miniature Stirling cooler machine for on-site refrigeration. The MEMS (Microelectromechanical systems) technology is investigated to design this machine. The concept could be used to provide cooling at chip scale and mitigate hot spots in electronic devices. Whereas numerous w...
Conference Paper
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The development of deep learning methodologies for the analysis of thermal power plant load losses requires a combination of real plant data and data derived from fundamental physics-based process models. For this purpose, a robust integrated power plant thermofluid process model of a complete +600MW coal-fired power plant was developed within the...
Conference Paper
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On the one hand the complexity of nano-scale thermofluid system considered as an expensive to investigate experimentally, on the other there are available discrete models such as Molecular Dynamics model offers an affordable and accurate choice for researchers to perform nano-scale investigation to look at different fluid aspects. In this paper we...
Article
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Deposition of scale inside wellbores is causing millions of dollars in damage every year. Any water production or injection in the gas or oil well is creating a possibility of scale formation. It can reduce formation porosity and permeability, it can block flow in the pipes, and it can damage downhole completion equipment. Some mineral scales such...
Article
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A combined numerical-experimental investigation is presented with focus on the effects of boundary-layer instabilities and transition on the wall cooling performance in a Mach 5 low-enthalpy flow over a flat plate, with coolant injection achieved through a row of slots. The numerical study has been performed through direct numerical simulation (DNS...
Article
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Thermal fluid characteristics of the lattice cooling channel have been investigated by measuring distributions of heat transfer coefficient. The heat transfer coefficient distributions have been obtained by visualizing steady-state local temperatures using temperature sensitive liquid crystal and foil heater. The measurement has been performed for...
Preprint
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Adding thermal conductivity enhancements to increase thermal power in solid-liquid phase-change thermal energy storage modules compromises volumetric energy density and often times reduces the mass and volume of active phase change material (PCM) by well over half. In this study, a new concept of building thermal energy storage modules using high-c...
Article
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Spray impingement on smooth and heated surfaces is a highly complex thermofluid phenomenon present in several engineering applications. The combination of phase Doppler interferometry, high-speed visualization, and time-resolved infrared thermography allows characterizing the heat transfer and fluid dynamics involved. Particular emphasis is given t...
Conference Paper
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The magnetic fluid is industrially important. Especially in the field of thermofluids, it is expected to be applied to promote natural convection and as a self-excited cooling device. However, magnetic fluid is black and opaque in which nanoparticles are dispersed at high density, and it is difficult to measure the internal flow field. By encapsula...