Purpose This study aims to propose a new composite metal fin structure to enhance heat transfer efficiency during the phase change energy storage (PCES) process in a hot water oil displacement system. Design/methodology/approach PCES numerical unit is developed by varying the radii of annular fins and the number of corrugated fins. The impact of the finned structure on melting characteristics, energy

Purpose This paper aims to report on a homogenized model for the anisotropic thermal conductivity of support structures constructed by the laser powder bed fusion (L-PBF) process, and its application to the numerical simulation of the L-PBF process. Design/methodology/approach Considering both analytical and numerical approaches, the model is developed across a temperature interval encompassing the

Purpose Aerodynamics plays a crucial role in enhancing the performance of race cars. Due to the low ride height, the aerodynamic components of race cars are affected by ground effects. The changes in pitch and roll attitudes during the car’s movement impact its ride height. This study aims to analyze the aerodynamic characteristics of race cars under specific pitch and roll attitudes to understand

Purpose This paper aims to explore, through a numerical study, buoyant convective phenomena in a porous cavity containing a hybrid nanofluid, taking into account the local thermal nonequilibrium (LTNE) approach. The cavity contains a solid block in the shape of a cross (+). It will be helpful to develop and optimize the thermal systems with intricate geometries under LTNE conditions for a variety of

Purpose Surface properties (smooth or roughness) play a critical role in controlling the wettability, surface area and other physical and chemical properties like fluid flow behaviour over the rough and smooth surfaces. It is reported that rough surfaces are offering more significant insights as compared to smooth surfaces. The purpose of this study is to examine the effects of surface roughness in

Purpose Continuous fiber-reinforced thermoplastic composites are a class of materials highly valuable for structural applications and modeling of heat transfer within them is critical to the design of their processing methods. However, the fiber reinforcement leads to highly anisotropic thermal conduction. Among a variety of methods to account for anisotropic thermal conductivity, continuum models

Purpose Agricultural crops play a crucial role in food security and require commensurating environmental conditions, including adequate rainfall to ensure optimum growth. However, in the recent past, a reduction in the agriculture crop yield has been observed due to the deteriorating rainfall pattern. This paper aims to present a novel mathematical model to analyze the impact of rainfall on the growth

Purpose The main purpose of this paper is given below: To present a mathematical model of a two-phase Stefan problem including a moving phase change material and variable thermophysical properties. To find a numerical solution of the problem to discuss the dependence of considered phase change problem on variable thermal conductivity, variable specific heat and Peclet number. Design/methodology/approach

Purpose This paper is concerned with the study of the propagation of Rayleigh waves in a homogeneous isotropic, generalized thermoelastic medium with mass diffusion and double porosity structure using the theoretical framework of three-phase-lag model of thermoelasticity. Design/methodology/approach Using Eringen’s nonlocal elasticity theory and normal mode analysis technique, this paper solves the

Purpose This study aims to assess the accuracy of degree adaptive strategies in the context of incompressible Navier–Stokes flows using the high-order hybridisable discontinuous Galerkin (HDG) method. Design/methodology/approach The work presents a series of numerical examples to show the inability of standard degree adaptive processes to accurately capture aerodynamic quantities of interest, in particular

To achieve carbon peaking and carbon neutrality goals, the CO2 transcritical power cycle is regarded as a promising technology for waste heat recovery. Variations in the working conditions of the engine can lead to significant fluctuations in waste heat. Therefore, to enhance adaptability to changes in heat sources, this study focuses on natural gas engines and proposes a dual split flow system for

Purpose This paper aims to study the effects of varying inlet channel angle in a novel microfluidic architecture blood plasma separation ability over range of hematocrit values (5–45%) at multiple flowrates. Design/methodology/approach CAD designs for both micro architectures were designed in SOILWORKS. In the second step, these designs were imported into ANSYS to perform where meshing, model selection

Purpose The purpose of this research is to investigate the feasibility of using the components series connection (CSC) method to predict the performance of a newly developed micro turbine engine (MTE) under rated operating condition. Design/methodology/approach The main research object is the MTE with known factory performance parameters, and the finite element method is used to discretize its main

Knowledge of phase equilibria and critical properties of CO2 + carboxylic acid systems is essential for supercritical fluid extraction (SCFE) processes, such as oil deacidification. However, modeling these systems is challenging due to their highly asymmetrical behavior. In this study, we apply the Group Contribution with Association Equation of State (GCA-EOS) to model vapor−liquid and liquid−liquid

Enhanced oil recovery (EOR) involves several techniques, including the injection of gas (such as natural gas, nitrogen, or CO2) into the reservoir to increase its pressure, thereby displacing oil from one or more injection wells to production wells. For this process to be effective, it is essential that the injected gas and the oil reach a homogeneous state. Particularly, the First-Contact Minimum

Supercritical water gasification (SCWG) technology enables the efficient utilisation of lignite to produce H2, CO, and CO2. Coal gasification differs under different atmospheres and H2 promotes the pyrolysis of carbon structures. While simultaneous increases in H2, CO, and CO2 are observed, their combined effect on the SCWG of coal remains unknown. Formic acid (FA) was used to produce H2, CO, and CO2

Purpose This investigation is devoted to analyze the electroosmotic flow characteristics in a sinusoidal micropipe through a porous medium. This study aims to investigate the impact of surface waviness on Darcy–Brinkman flow in the presence of electroosmotic force, achieved through the unification of perturbation techniques. Design/methodology/approach Analytical approximate solutions for the governing

Purpose This study aims to explore the hydrodynamic and thermal behavior of an incompressible fluid flowing between uniformly corotating disks with finite radii. The narrow gap between the disks necessitates accounting for slip flow in the radial direction, departing from the classic no-slip model. Design/methodology/approach The author uses a perturbation approach and derives full analytical approximations

High-temperature components in the supercritical power plant experienced alternating thermal stresses under deep peak regulation, accelerating the cracking and spalling of the oxide film formed on the steam-side of super-heaters and re-heaters. This study employed the corrosion testing and finite element simulations to investigate the failure behavior of oxide films on super-heaters made by heat-resistant

Purpose This study aims to get a better understanding of the impact of streamlined high-speed trains (HSTs) with geometric uncertainty on aerodynamic performance, as well as the identification of the key parameters responsible for this impact. To reveal the critical parameters, this study creates a methodology for evaluating the uncertainty and sensitivity of drag coefficient induced by design parameters

Agro-industrial residues, such as soybean husks, are low-cost and can be converted into products. Therefore, the objective of this work was to evaluate the influence of temperature (230, 260, 300, and 340 °C) and the solvent/feed ratio (40 and 80) in the subcritical water process in semi-continuous mode under soybean husks in fermentable sugar, platform chemicals, bio-oil and hydrochar yields. Contextually

Purpose This paper aims to perform a linear and nonlinear analysis of the stability of a chemically reacting Newtonian fluid in a Darcy porous medium. The purpose of selecting both analyses is to investigate the probability of subcritical instability resulting from combustion. Design/methodology/approach The chemical reaction problem in a Darcy porous medium with Arrhenius kinetics is considered. The

Purpose The aerodynamic load caused by high-speed train operation may lead to severe vibration of the pedestrian bridge, thus causing great safety hazards. Therefore, this study aims to investigate the aerodynamic loading characteristics of a pedestrian bridge when a high-speed train passes over the bridge, as well as to evaluate the vibration response of the aerodynamic loads on the bridge structure

Purpose This study aims to investigate experimentally and numerically the thermal analysis of a wavy diverging-converging corrugated enclosure, partitioned into two parts under the effect of magnetohydrodynamic (MHD) natural convection. The left part was filled with Al2O3/C2H6O2 nanofluid, while the right part was Al2O3/C2H6O2 saturated by a porous medium, featuring a corrugated cylinder at the center

Purpose Nowadays fossil fuel prices have increased; therefore, consumption of energy reduction has become a significant issue. Hence, this study aims to explore energy-efficient mechanical devices and their energy management. Design/methodology/approach This study focused on numerical analysis of various factors, including pressure drop, sensitivity, heat transfer and friction factor. This study compared

Purpose The purpose of this study is to investigate the simultaneous effects of normal wall transpiration, stretching strength parameter, velocity slip and nanoparticles on the flow of a ternary hybrid nanofluid through an elastic surface. The goal is to understand the behavior of the flow field, temperature distribution, skin friction and temperature gradient under these conditions, and to explore

Chemical depolymerization of polylactic acid (PLA) was demonstrated in supercritical carbon dioxide medium. No catalyst, organic solvent or water was employed in the reaction. The primary feedstocks used in ring opening polymerization of PLA, lactide isomers, were produced with high yield. More specifically, lactides were produced as the sole nongaseous products with a 93 % yield based on the initial

Supercritical carbon dioxide (scCO2) was selected as the medium for the synthesis and dyeing of four naphthalimide dyes (Y-1, Y-2, Y-3, and Y-4). They were synthesized through the reaction of 4-bromo-1,8-naphthalene dianhydride with various amines. These dyes demonstrated good photophysical properties and thermal stability, aligning with the prerequisites for scCO2 dyeing. Consequently, the scCO2 dyeing

Biocompatible implants are essential for improving human health and longevity. Incorporating bioactive compounds, such as eugenol, into implant materials can improve biocompatibility and therapeutic efficacy. This study examines the effects of supercritical eugenol impregnation on the physical properties of 3D-printed polylactic acid samples produced by Fused Deposition Modeling. Impregnation was performed

Purpose This paper aims to explore dual solutions for the flow of a hybrid nanofluid over a permeable melting stretching/shrinking sheet with nanoparticle shape factor, second-order velocity slip conditions and viscous dissipation. The hybrid nanofluid is formulated by dispersing alumina (Al2O3) and copper (Cu) nanoparticles into water (H2O). Design/methodology/approach The governing partial differential

This study aimed to obtain bioactive compounds from the residue from pineapple (Ananas comosus L. Merril) juice processing, using supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE). The SFE were performed using ethanol as a co-solvent and evaluating different pressure, temperature, and co-solvent percentage. For the PLE, temperature and ethanol percentage were assessed. The

The effects of the extraction conditions on the recovery and isomerization of the UV-absorbing saclipins from the edible cyanobacterium Aphanothece sacrum by subcritical water were investigated. The extraction temperature (100–160 ℃) did not affect the extraction efficiency of saclipins, but the pressure (5–15 MPa) had a significant effect. The saclipin B (cis-configuration) ratio in the extract increased

Ilex paraguariensis is a source of bioactive compounds, which have been demonstrated to mitigate neurological disorders and enhance athletic performance. This study aimed to decaffeinate yerba mate using supercritical fluid extraction, followed by caffeine purification. The purified extract was encapsulated in gelatin via spray drying, and its release profile was evaluated in simulated gastric fluid

Purpose This study aims to investigate the heat and mass transfer characteristics of a temperature-sensitive ternary nanofluid in a porous medium with magnetic field and the Soret–Dufour effect through a tapered asymmetric channel. The ternary nanofluid consists of Boron Nitride Nanotubes (BNNT), silver (Ag) and copper (Cu) nanoparticles, with a focus on understanding the thermal behaviour and performance

To meet the demands of the evolving circular economy, there is a growing need for renewable resources as base materials for innovative, easily recyclable products. Lignin, the second most abundant biopolymer, has emerged as a promising source of aromatics and reinforcing agent in polymer composites. For the successful manufacturing of homogeneous composite materials, good bonding between the coexisting

Purpose This paper aims to study numerically the non-Newtonian solution of carboxymethyl cellulose in water along with copper oxide nanoparticles, which flow turbulently through twisted smooth and finned tubes. Design/methodology/approach The twisted-tape inserts of rectangular and triangular sections are investigated under constant wall heat flux and the nanoparticle concentration varies between 0%

Araçaúna (Psidium myrtoides) is a native fruit from the Brazilian Atlantic Forest. It was studied for the proximate composition of its flour and sequential extraction using supercritical fluid extraction (SFE) in the first stage with CO2 and pressurized liquid extraction (PLE) with ethanol and water in the second and third stages, respectively, at 50°C and 60°C. The proximate analysis revealed essential

Carrageenan, a polysaccharide mostly extracted from Kappaphycus alvarezii (KA), is valuable for cosmetic and food uses due to large quantities of κ-carrageenan. High-pressure sequential extractions can recover high-purity carrageenan from KA, adequate for aerogel production. The biopolymer properties such as size, shape, and sulphate groups affect the gel form and aerogel characteristics. In this work

The Internal flow mechanisms and windage loss in impeller back gap of a supercritical carbon dioxide (sCO2) radial inflow turbine with scallops are comprehensively investigated in this paper. The study emphasizes the effects of scallop depth and leakage outlet pressure. The results indicate that scallop structures lead to a degradation in overall turbine performance. Under design conditions, a turbine

Purpose This research focuses on the controlling irreversibilities in a radiative, chemically reactive electromagnetohydrodynamics (EMHD) flow of a nanofluid toward a stagnation point. Key considerations include the presence of Ohmic dissipation, linear thermal radiation, second-order chemical reaction with the multiple slips. With these factors, this study aims to provide insights for practical applications

Despite the impressive characteristics of biological metal organic frameworks (bioMOFs) for their use as drug delivery systems (DDs), there are still some parameters related to their structural stability and processing routes that have decelerated their realistic application in this field. Both drawbacks are unraveled in this work for the microporous bioMOF CaSyr-1 by using supercritical CO2 (scCO2)

This research investigates the extraction of compounds from Nepeta crispa (N. crispa), utilizing supercritical carbon dioxide green solvent, for the first time. Using RSM, the study examines the impact of pressure (15–25 MPa), temperature (313–333 K), and co-solvent (0.5–3.5%) on the extraction yield. The antioxidant activity of the essential oil is assessed through Ferric Reducing Antioxidant Power

Sediment flushing through bottom tunnels has been widely applied in engineering practice to alleviate reservoir sedimentation. However, there is limited understanding of whether flushing can be acc...

In the cockpit, minimising the pilots' thermal discomfort due to solar exposure while ensuring clear visibility is essential. This study numerically examined the solar radiation effect on thermal f...

The transcritical CO2 (T-CO2) power cycle is regarded as one of the most promising alternatives to the steam power cycle in nuclear power plants. However, these plants often operate with transient cold source conditions, leading to deviations from the optimal design point and performance degradation. Therefore, this study examines a double recompression T-CO2 power cycle to optimize the design point

Purpose This paper aims to present a numerical investigation for two-dimensional fractional Helmholtz equation using the Aboodh integral homotopy perturbation transform scheme (AIHPTS). Design/methodology/approach The proposed scheme combines the Aboodh integral transform and the homotopy perturbation scheme (HPS). This strategy is based on an updated form of Taylor’s series that yields a convergent

High-pressure gas might affect the molecular chain movement, chain interaction, and crosslinking behavior of MVQ during the saturation process. In this paper, by comparing crosslinking exothermic behaviors of MVQ in air, CO2, and N2, it is found that the supercritical CO2 (scCO2) can promote crosslinking reaction of MVQ through enhancing the swelling and molecular chain's mobility. The result of rheological

Steam explosion (SE) pretreatment and sequentially subcritical water hydrolysis (SWH) was studied. Industrially, there is an advantage in using this process strategy, since it uses the same equipment and instrumentation, without the need to transport the raw material in separate stages. The influence of severity factors (SF) (2.75, 3.05, and 3.35) and solvent used (distilled water and 0.5 % w/w of

This pioneering study is the first to explore the extraction of Calycolpus goetheanus using supercritical carbon dioxide (scCO2), novel approach to harnessing the bioactive potential of this Amazonian species. By examining extractions under varying temperatures (35 and 45 °C) and pressures (150, 250, and 350 bar), the research not only evaluates the yields but also uncovers significant differences

Dyes abundance in wastewaters poses environmental threats, and a cost-effective strategy to remediate dyed water is adsorption: this process could be enhanced using nanostructured sorbents, that expose high surface areas.

The impregnation of piperine and black pepper extract into poly (L-lactic acid) (PLLA) films using supercritical CO2 was investigated. Piperine was a model to determine the influence of operating conditions of pressure (10 and 12 MPa) and temperature (40 and 50 °C) on the impregnation yield. The most favorable conditions were obtained at 10 MPa and 50 °C and were used in the incorporation of piperine

We developed a methodology to study the extraction of high-value solutes directly from suspensions of finely disrupted substrates. For that, we modelled the high-pressure phase equilibrium for the ternary (CO2 + ethanol + water) system using experimental literature data. Different compositions of hydroethanolic mixture and CO2 were loaded into an extraction vessel set at 30–35 MPa and 40–50 °C during

Supercritical carbon dioxide (SC-CO2) was used as an alternative method of dyeing alpaca fiber. This study analyzes the colorfastness to laundering as a function of operating parameters. The fiber was subjected to a pretreatment (Impregnation), where it was soaked in an acidulated solution of Nylosan Yellow N-3RL dye, squeezed through a padder roller and then dyed in the SC-CO2 system. Dye concentrations

The computation of Global Phase Equilibrium Diagrams (GPED) for binary systems, including critical and three-phase equilibrium curves, is crucial for analyzing process conditions and assessing thermodynamic models. In the past two decades, algorithmic strategies and GPEC software have become essential tools. However, numerical problems can arise with the original algorithm for highly asymmetric systems

Purpose Double flow-focusing nozzles (DFFNs) form a coaxial flow of primary liquid with micro-crystalline samples, surrounded by secondary liquid and focusing gas. This paper aims to develop an experimentally validated numerical model and assess the performance of micro-jets from a DFFN as a function of various operating parameters for the water–ethanol–helium system, revealing the jet's stability

Purpose Using passive techniques like twisted tapes and corrugated surface is an efficient method of heat transfer improvement, since the referred manners break the boundary layer and improve the heat exchange. This paper aims to present an improved dual-flow parabolic trough collector (PTC). For this purpose, the effect of an absorber roof, a type of turbulator and a grooved absorber tube in the presence

Purpose Carotid artery is often associated with plaque deposition because of its shape and associated flow features. The shape of stenosed bifurcation is characterised by bifurcation angle (ß), planarity angle (α) and severity of stenosis (b). In the present work, three-dimensional numerical computations have been performed to analyse the effect of these geometrical parameters of carotid bifurcation

Purpose This study aims to investigate entropy generation through natural convection and examine heat transfer properties within a partially heated and cooled enclosure influenced by an angled magnetic field. The enclosure, subjected to consistent heat production or absorption, contains a porous medium saturated with a hybrid nanofluid blend of Cu-Fe3O4 and MoS2-Fe3O4. Design/methodology/approach The

Renowned for its medicinal properties, barbatimão bark extract contains bioactive compounds susceptible to degradation, necessitating their safeguarding within a stable matrix for diverse biomedical applications. This study investigates using high-pressure liquid impregnation (HPLI) to load barbatimão extract into biopolymeric membranes at 30, 45, and 60 °C, and 11 MPa. HPLI combines the simplicity

Purpose This study aims to investigate the formation and characteristics of Taylor bubbles resulting from short-time gas injection in liquid-conveying pipelines. Understanding these characteristics is crucial for optimizing pipeline efficiency and enhancing production safety. Design/methodology/approach The authors conducted short-time gas injection experiments in a vertical rectangular pipe, focusing