Melting Heat Research Articles

Dulcitol/Starch Systems as Shape-Stabilized Phase Change Materials for Long-Term Thermal Energy Storage.

In recent years, there has been an increasing interest in phase change materials (PCM) based on dulcitol and other sugar alcohols. These materials have almost twice as large latent heat of fusion as other organic materials. Sugar alcohols are relatively cheap, and they can undergo cold crystallization, which is crucial for long-term thermal energy storage. The disadvantage of dulcitol and other sugar alcohols is the solid-liquid phase transition. As a result, the state of matter of the material and its volume change, and in the case of materials modified with microparticles or nanoparticles, sedimentation of additives in liquid PCM can occur. In this study, we obtained shape-stable phase change materials (SSPCM) by co-gelation of starch and dulcitol. To characterize the samples obtained, differential scanning calorimetry (DSC), step-mode DSC, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used, and they were also used to test for shape stabilization. The results show that the obtained systems have great potential as shape-stabilized phase change materials. The sample dulcitol/starch with a 50:50 ratio exhibited the highest heat of cold crystallization, up to 52.90 J/g, while the heat of melting was 126.16 J/g under typical DSC measuring conditions. However, depending on the applied heating program, the heat of cold crystallization can even reach 125 J/g. The thermal stability of all compositions was higher than the phase change temperature, with only 1% mass loss occurring at temperatures above 200 °C, while the phase change occurred at a maximum of 190 °C.

Urea-aided phase change thermal energy storage performance regulation for thermal management

Organic phase change cold storage materials show significant potential in various fields, including cold chain transportation, food and drug preservation, and battery thermal management. However, most organic phase change cold storage materials struggle with issues like difficult temperature control and flammability, which severely limit their application and development. In this study, by physically blending a modulated urea solution and alcohol with the polyethylene glycol lauryl ester (PLE), and adjusting the mass of urea and alcohol, a series of samples are prepared. Detailed characterization and analysis reveal that the prepared phase change materials (PCMs) possess excellent cold storage properties. These materials achieve precise control of melting temperatures ranging from −13.42 to −3.80 °C, with a maximum latent heat of melting of 85.12 J/g. Interestingly, this study reveals that seven groups of samples exhibit flame retardant effects. These properties are critical for enhancing the safety and efficiency of the materials in practical applications. This innovative approach not only addresses the temperature control and flammability issues but also expands the potential use of PCMs in various industries. Therefore, this study offers an effective method for developing advanced phase change cold storage materials, contributing to technological advancements in thermal management.

Bridge-grafted EG/BCN encapsulated PW with effectively improved thermal conductivity and battery thermal management performance

Although phase change materials (PCMs) have been widely utilized in thermal management of batteries, they still confront the challenges of high cost and low thermal conductivity. In this study, low-cost composite PCMs with high energy-storage capacity, thermal conductivity and outstanding thermal management performance were proposed by utilizing the synergetic porous structure of expanded graphite (EG) and boron carbon nitrogen (BCN) nanospheres through bridge-grafting method to encapsulate paraffin wax (PW), which effectively enhanced the anti-leakage and comprehensive performance. The incorporation of BCN nanospheres endowed the composite PCMs with extremely improved thermal conductivity of 1.611 W/(m·K), which was 421 % higher than that of pure PW. And the highly improved melting and crystal latent heat of the composite PCMs reached 184.37 J/g and 185.39 J/g, respectively, which also exhibited excellently thermal-cycling stability. The photo-thermal conversion efficiency of the composite PCMs was enhanced to 92.6 %. When applied to battery thermal management, the maximum temperature of battery wrapped with the composite PCMs was 11.9 °C lower than that of the batteries without PCMs, which confirmed an outstanding battery thermal management effect of the composite PCMs.

A numerical study on metallic melt infiltration in porous media and the effect of solidification

The melt infiltration in porous debris is of importance to severe accident prediction and mitigation in nuclear power plants (NPPs), but its mechanism remains elusive. In this study, a computational fluid dynamics (CFD) model is proposed to simulate the evolution of melt infiltration within porous media, incorporating both solidification and melting processes. The CFD model is validated against the experiment (REMCOD facility) and Moving Particle Semi-implicit (MPS) simulation results. Building upon this validated model, the influence of the melt superheat, the initial particle temperature, and its surface wettability on melt infiltration dynamics are mainly analyzed. It is found that increased initial melt superheat enhances melt infiltration length and rate; higher initial particle temperatures promote deeper and faster infiltration, while lower temperatures may result in solidification that blocks further infiltration. Additionally, the wettable particulate bed can enhance melt relocation and heat transfer, but it also accelerates the solidification of the melt, which complicates the infiltration process. Furthermore, phase changes could intensify melt flow instability. This work may expand our understanding of melt infiltration dynamics and pave the way to severe accident modeling in NPPs.

Investigation of the degradation behaviour of poly-L-lactic acid braided stents under real-time and accelerated conditions

Degradation tests are a key step in the development of a bioresorbable stent. The present study focused on the degradation of bioresorbable stents made from PLLA filaments, and examined the variation of the physical, thermal, and mechanical properties of the material and the devices under both real-time and accelerated degradation conditions. Results showed that the undegraded filaments were highly crystalline and composed by both α and α′ crystalline phases, induced by both the melt spinning and heat treatment processes. The latter was shown to have an important influence on the further formation of α crystalline phase and therefore crystalline structure perfectioning. Real-time degradation tests showed that the devices maintained structural stability for up to a year, meeting the required 6-month degradation period for vascular stents. Degradation was shown to primarily affect the crystalline regions, and to cause a gradual loss of material ductility before any mass loss or decrease in crystallinity. In turn, a constant decrease of molecular weight was observed, with stent failure occurring around day 389 due to a drop in molecular weight below 10,000 g/mol. Accelerated degradation tests mirrored real-time results until mass loss began. Subsequently a slower molecular weight decrease was observed, with an increase and subsequent decrease of material crystallinity. The consistency of the data obtained between real-time and accelerated degradation before mass loss confirmed the possibility to gain insights into real-time degradation through an accelerated protocol. However, attention must be paid to the initial molecular weight of the material, which has been shown to highly influence the acceleration rate. This study provides a wide range of experimental data both on the real-time and thermally accelerated degradation behaviour of PLLA braided stents that can be used as benchmark for further studies in the field.

Understanding melting behavior of aluminum clusters using machine learned deep neural network potential energy surfaces.

Deep neural network-based deep potentials (DP), developed by Tuo et al., have been used to compute the thermodynamic properties of free aluminum clusters with accuracy close to that of density functional theory. Although Jarrold and collaborators have reported extensive experimental measurements on the melting temperatures and heat capacities of free aluminum clusters, no reports exist for finite-temperature abinitio simulations on larger clusters (N > 55 atoms). We report the heat capacities and melting temperatures for 32 clusters in the size range of 48-342 atoms, computed using the multiple histogram technique. Extensive molecular dynamics (MD) simulations at twenty four temperatures have been performed for all the clusters. Our results are in very good agreement with the experimental melting temperatures for 19 clusters. Except for a few sizes, the interesting features in the heat capacities have been reproduced. To gain insight into the striking features reported in the experiments, we used structural and dynamical descriptors such as temperature-dependent mean squared displacements and the Lindemann index. Bimodal features observed in Al116 and the weak shoulder seen in Al52 are attributed to solid-solid structural transitions. In confirmation of the earlier reports, we observe that the behavior of the heat capacities is significantly influenced by the nature of the ground state geometries. Our findings show that the sharp drop in the melting temperature of the 56-atom cluster is a consequence of the change in the geometry of Al55. Mulliken population analysis of Al55 reveals that the charge-induced local electric field is responsible for the strong bonding between core and surface atoms, leading to the higher melting temperature. Our calculations do not support the lower melting temperature observed in experimental studies of Al69. Our results indicate that Al48 is in a liquid state above 600K and does not support the high melting temperature reported in the experiment. It turns out that the accuracy of the DP model by Tuo et al. is not reliable for MD simulations beyond 750K. We also report low-lying equilibrium geometries and thermodynamics of 11 larger clusters (N = 147-342) that have not been previously reported, and the melting temperatures of these clusters are in good agreement with the experimental ones.

Investigation of formation, microstructure and hardness of Ti-6Al-4V single tracks via Joule-fused filament additive manufacturing

Purpose This paper aims to investigate a novel additive manufacturing (AM) method for titanium alloy using Joule heat as the single heat source to melt TC4 wire, which intends to provide a new low-power, low-cost solution for the processing of titanium alloys. Design/methodology/approach When current flows through the wire and the substrate, Joule heat will be generated to melt the wire and join the wire with the substrate. By stacking the wire layer by layer, finally a part can be formed. The cross-sectional morphology, microstructure and hardness of TC4 single track deposits formed by Joule heat melting wire AM were investigated by various characterization methods. Findings The melting width and melting penetration decreased with the increase of printing speeds. There is no obvious change in single track morphology with the change of printing pressures. The melting width and melting penetration increased with the increase of printing currents. The observation of the internal microstructure of a single track reveals a decrease in grain size as printing speeds increase. The average hardness of the single track was about 363 HV, which is comparable to the hardness of the parts fabricated by selective laser melting process. The printing power is less than 300 W, which is lower than other AM processes. Originality/value This paper provides a novel solution for the processing of titanium alloy parts. Compared with other expensive energy sources, this work only uses an ordinary DC power supply as the energy source. The printing process is simple and the cost is low. The power is much lower than other AM processes.

Effect of dual NEPCM and tapered fins on thermal runaway control in lithium-ion batteries

This research investigates the thermal performance of dual phase change materials (PCMs) RT82 (PCM1) and RT27 (PCM2) using tapered fins and nanoparticles to improve their thermal management capabilities, specifically for controlling excessive heating in lithium-ion battery cells. The primary objective is to enhance heat transfer efficiency and melting characteristics of dual PCMs by incorporating alumina (Al2O3), molybdenum disulfide (MoS2), and single-walled carbon nanotubes (SWCNTs) nanoparticles at varying volume fractions and configuring tapered fins in different arrangements. A series of parametric studies were conducted to analyze the impact of these modifications on the thermal transport and solid-liquid transition characteristics of the PCMs. The key findings indicate that the incorporation of nano-sized particles significantly enhances the thermal conductivity of PCMs, with SWCNTs showing the highest improvement. The PCM system with 6 % SWCNTs nanoparticles exhibited a 41.85 % increase in melting characteristics compared to the baseline PCM. The study also reveals that increasing the number of fins from two to eight results in a 94.28 % increase in the melting rate for RT82 and a 50 % increase for RT27. Furthermore, the combination of increased nanoparticle concentration and fin number leads to a 12.17 % rise in melt pool temperature distribution for 2 % SWCNTs and 14.08 % for 6 % SWCNTs. The enhanced thermal conductivity and efficient heat transfer due to the synergistic effect of fins and nanoparticles result in faster phase transitions and improved temperature regulation within the system. These findings underscore the potential of optimized PCM configurations with advanced materials for superior thermal management solutions in high-heat applications, effectively extending the operational efficiency and lifespan of thermal systems like lithium-ion batteries.

Underplating-induced trans-crustal melting and maturation of Neoarchean continental crust in the North China Craton

A global change in granitoid compositions from early predominantly sodic tonalite-trondhjemite-granodiorites (TTGs) to later TTGs and more potassic granites occurred during the late Archean, coupled with a major period of crustal maturation. However, the detailed relationship between granitoid chemical evolution and the maturing crustal process remains enigmatic. Successive granitoid magmatism including late Neoarchean TTGs and high-K granites occurred in the Western Shandong Province granite-greenstone belt (WSP) of the North China Craton and thus preserves crucial clues of the crustal maturation process. In this study, petrology, whole-rock geochemistry, and zircon U-Pb and Lu-Hf isotopes are reported for the late Neoarchean TTG gneisses, monzogranites, and minor metabasaltic to andesitic rocks from the WSP. The ca. 2560−2540 Ma TTG gneisses show low MgO, K2O/Na2O, but high (La/Yb)N, Sr/Y, and absence of Eu anomalies, indicating their derivation from partial melting of the thickened lower mafic crust. The ca. 2530−2500 Ma monzogranites are characterized by systematically high SiO2 and K2O/Na2O, but low MgO and Sr/Y, and moderately negative Eu anomalies, revealing they were formed by intracrustal reworking of local TTGs and sedimentary rocks in the middle to upper crust. Geochemical variations of these crustal-derived granitoids suggest that they were formed by melting at gradually higher crustal levels with the melt zone moved gradationally from the eclogite stability field into the plagioclase stability field. The ca. 2530−2500 Ma calc-alkaline metabasaltic to andesitic rocks sourced from metasomatized mantle outline roles of mantle-derived magma underplating in contributions of heating and trans-crustal melting magmatism. The long-term melting processes facilitated the upward movement of volatiles and heat-producing elements from deep to shallow crustal levels, and introduced K-enriched monzogranites into the upper crust, leaving a refractory, strengthening, and tectonically stable lower crust. Secular compositional evolution of crustal-derived granitoids reveals that continuous crustal reworking drove lithosphere differentiation and paved the way for the maturation of the Archean continental crust.

Maximizing thermal management of photovoltaic-thermal systems with proper configuration of porous fins and phase change materials

Effective thermal management is crucial to enhance the performance and longevity of photovoltaic-thermal (PVT) systems. Phase change materials (PCMs) offer a promising solution for absorbing excess heat from PV modules; however, their poor thermal conductivity limits their effectiveness. This work explores the incorporation of porous fins within PCMs to improve heat absorption and thermal regulation in PVT systems. A detailed mathematical model is developed to analyze the effects of varying fin porosity (0.85–0.95), fin thickness (7–21 mm), fin height (7–21 mm), and fin inclination (−15°–30°) on PCM melting and PVT cooling performance. Results show that optimally configured porous fins significantly enhance PCM melting rates and heat extraction from PV cells. Incorporating optimal fins reduces peak PV temperatures by up to 5 °C compared to PCM alone at irradiation rate of 1000 W/m2. Meanwhile, reducing the fin thickness from 21 to 7 mm accelerates the overall PCM melting rate by 14 %. The cooling performance also shows a nonlinear increase with fin tilt angle, with maximum enhancement occurring at 15° downward tilt for the studied configuration. The optimized fin-enhanced PVT design achieves 3.1 % higher electrical efficiency and 15 % increase in thermal efficiency compared to conventional PCM-PVT systems without fins. Findings provide design guidance to harness porous fins for maximized PCM-based cooling of PVT systems.

Highly thermally conductive and shape-stabilized phase change materials with desirable solar/electric-to-thermal conversion performance based on high-modulus graphite/PVA foam

The widespread utilization of phase change materials (PCMs) has been impeded by challenges such as leakage, low thermal/electrical conductivity, and inadequate light absorption. Although constructing interconnected three-dimensional (3D) carbon networks within PCMs can mitigate these issues, their complex and energy-intensive fabrication processes, coupled with insufficient mechanical strength causing significant leakage and collapse of liquefied PCMs under external loads or impacts, hinder their practical application. Herein, we present a novel approach for the preparation of 3D graphite/polyvinyl alcohol foam (GPF) through a simple vacuum foaming combined with air-drying method. The obtained GPF-5 exhibits impressive compression strength (4.46 MPa) and compression modulus (93.1 MPa) at low density of 0.30 g/cm3. Upon impregnation with polyethylene glycol (PEG), GPF-5/PEG exhibits notable mechanical strength (7.62 MPa), contributing to its thermal shape stability and resistance to leakage. Even when subjected to temperatures above the melting point of PEG under external loads, GPF-5/PEG maintains its original shape without any liquid leakage. Due to the efficient construction of 3D thermal conductivity pathways within GPF, GPF-5/PEG demonstrates a high thermal conductivity of up to 3.48 W/m K−1 with graphite contents of 21.1 wt%, representing an increase of 136 % and 1640 % compared to graphite/PEG (with equivalent graphite content) and pure PEG, respectively. Additionally, GPF-5/PEG displays high latent heat of melting (136.8 J/g) and superior thermal cycling stability. Moreover, GPF-5/PEG demonstrates high solar-to-thermal and electric-to-thermal energy conversion capabilities, highlighting their potential for diverse applications. The work offers a rational strategy for fabricating high-modulus carbon foam, which can be used for PCMs-based multi energy conversion and storage systems with high thermo-mechanical properties.

Thermal characteristics of conical heat storage tank filled by metal foam: Optimization by response surface analysis

The heat storage efficiency of heat storage tank is a challenge to optimize the utilization of solar energy. Therefore, improving the efficiency of heat storage tank has become the main research focus. In this study, the conical tank design optimized for natural convection and the metal foam addition enhanced for thermal conduction are combined. However, there are some mutual constraints between two optimization methods. Therefore, the single factor analysis coupled response surface optimization method was used in this study to optimize the conical heat storage tank filled with metal foam. Firstly, the influence and optimization interval of each factor are discussed through single factor analysis. Then, the comprehensive influence of three factors is analyzed by response surface method. Finally, the heat storage characteristics, natural convection characteristics, melting fraction and temperature uniformity of the optimized model were evaluated. The results show that the optimized heat storage tank has stronger natural convection intensity and stronger melting heat storage performance than three comparative heat storage tanks.

Effects of Arrhenius activation energy and melting heat transfer on Carreau fluid through a stretching sheet

ABSTRACT This article investigates the effect of activation energy on Carreau fluid flow in the presence of variable thermal conductivity, inclined magnetic field, melting heat transfer, and Soret and Dufour phenomena. A set of suitable similarity transformations is applied for transforming the governing partial differential equations (PDEs) considered for the physical phenomena into non-linear ordinary differential equations (ODEs). We obtained the results by solving the non-linear ODEs numerically which describe the behavior of the velocity, temperature, and concentration profiles of the fluid against the governing parameters and illustrated these graphically. The velocity distribution decreases for angle of inclination while it is increasing against higher melting parameter. The temperature distribution enhances with higher modified Dufour parameter and Prandtl number while it declines for thermal conductivity, activation energy, and melting parameters. The concentration distribution increases for melting parameter, Soret number, and activation energy parameter while decreasing for temperature difference parameter, Schmidt number, and reaction rate parameter. Skin friction, Nusselt and Sherwood numbers are evaluated numerically against the various governing parameters. Accuracy of the present work is illustrated and established through comparison carried out for skin friction versus magnetic parameter with existing results in the literature.

Statistical analysis on the rate of heat transfer of radiative water‐based hybrid nanofluid flow over an elongating surface due to velocity slip and melting heat condition

AbstractThe performances of the heat transfer due to dissipative heat likely magnetic dissipation is a challenging field of research because of it's diversifies applications in industries and engineering. Particularly, nowadays, in biomedical field of research the implementation of dissipation along with thermal radiation is vital. Based upon the current scenario, the present investigation leading to the role of magnetic dissipation vis‐à‐vis thermal radiation on the water‐based hybrid nanofluid past an electro‐magnetized elongating surface associated with melting boundary conditions. The adaptation of the transformed rule particularly, similarity rules are useful to convert the proposed set of problems in to ordinary. Further, shooting‐based numerical technique is proposed to handle the governing equations. The interesting and novel approach in this topic is the use of robust statistical technique, that is, response surface methodology for the optimizing Nusselt number for the use of various factors. Moreover, the validation is obtained by conducting a hypothetical testing using analysis of variance (ANOVA) which conforms a best output model for appropriate response. Further, the major outcomes of the study are depicted as; the unsteadiness parameter decelerates the velocity profile of the hybrid nanofluid for the interaction. However, the increasing particle concentration favours in enhancing the heat transport phenomenon.

Promising areas of slag processing in ferrous metallurgy

The characteristics of promising areas of slag processing in ferrous metallurgy are given. An increase in requirements for environmental protection was noted. Modern slag processing includes primary and secondary processing, which differ in the physical state of the slag. The technological foundations of mass processing of slag have been formed at the Ural Institute of Metals. An assessment of the state of slag processing shows that the capacity of crushing and screening plants, mainly due to complexes purchased abroad, exceeds the yield of slag of current production and leads to a decrease in dumps. Modern areas of economics and environmental protection require the creation and implementation of new technologies and equipment for the processing of slag in liquid and solid form, improving the quality of products at all stages of processing. Processing of slag in liquid form at furnace (or located near melting furnaces) plants will make it possible to organize the technological process in highly economical environmentally friendly small-sized units, to adjust the composition and properties of slag, to expand the range and quality of the resulting products, to create conditions for the utilization of melt heat and the recycling of slag processing products. These processes reduce the environmental burden on the environment, reduce material, energy and operational costs, and expand the range and quality of the products obtained

Late Triassic extension of thickened lithosphere of the East Kunlun orogenic Belt, northern Tibetan Plateau: Evidence from the geochemistry and geochronology of mafic magmatism

The East Kunlun Orogenic Belt (E-KOB) evolved into an extensional tectonic setting with plenty of mafic magmatism after the closure of the Paleo-Tethys Ocean. However, the deep tectonic system and geodynamic processes in this context still need further clarification. The detailed field geological, petrological, geochronological and geochemical works carried out on the Yeniugou gabbros in this study could provide key evidence for clarifying this issue. The gabbros are predominantly composed of clinopyroxene, orthopyroxene, plagioclase, olivine and ilmenite. Zircon U–Pb dating results suggest that their formation at ca. 209–207 Ma. Characterized by a relatively low SiO2 content and a moderate total alkaline content, these rocks are classified as alkalic to subalkaline series. High values of Mg# (42.2–59.4) and high concentrations of compatible elements (V, Cr, Co, Ni) suggest that their parent magma was generated through high partial melting of a lithospheric mantle source. The left-leaning rare earth element distribution patterns, combined with the characteristic spikes of Nb-Ta, indicate that they were originated from the lithospheric mantle metasomatized by subducting components. The positive zircon εHf(t) values (0.1–5.7), along with elevated Nb/La ratios (0.45–0.67), further confirm a small amount of asthenosphere mantle contribution. Elevated Zr/Y ratios, plus a slightly positive correlation between Alz and TiO2 in clinopyroxene, imply that they formed within an extensional setting, where the upwelling of the asthenospheric mantle provided heat for partial melting of the metasomatic lithospheric mantle. Combined with previous data, we suggest that E-KOB underwent delamination of thickened lithosphere in the late Triassic, following the closure of the Paleo-Tethys Ocean.

Ablation and molten layer flow simulation for plate model of SiO2f/SiO2 composite material using particle method

In this paper, the moving particle semi-implicit method (MPS) is extended from calculating free mobility to simulating the extremely viscous and temperature-dependent molten layer flow of SiO2f/SiO2 composite material under aerodynamic heating conditions, which includes strong heating and shear of incoming flow. A method for applying heat flux and airflow shear, based on the conceptual particle approach, has been established. Heat transfer, melting, solidification, and evaporation behaviors are considered, with temperature-dependent viscosity variations also accounted for. The ablative regression of the plate model is verified using experimental results of the SiO2f/SiO2 composite material, and results from convergence analysis demonstrate the accuracy of the space step size selection. Surface morphology analysis through three-dimensional computation indicates that the extended particle method also accurately describes the surface morphology of SiO2f/SiO2 composite material under aerodynamic heating conditions. Thus, the extended particle method accurately simulates both the ablation process and the surface morphology of the SiO2f/SiO2 composite material. The influences of acceleration and surface tension are discussed. Ablative recession, when subject to acceleration, is smaller than that observed in its absence. When exposed to surface tension, the liquid layer tends to form a spherical shape, and the particles behave as a cohesive unit, resulting in smaller ablative recession than in the absence of surface tension.

Heat transfer analysis and melting behavior of nano composite phase change materials (NCPCMs) in a reverse flow solar air heater

This paper presents a CFD investigation on heat transfer analysis and melting behavior of Nanocomposite Phase Change Materials (NCPCMs) in a Reverse Flow Solar Air Heater (RFSAH). Semicircular tubes filled with PCM are embedded on the top surface of the absorber plate. The study was conducted with three different nanoparticles (CuO, Al2O3, Fe3O4) based NCPCMs at three concentrations of 0.1, 0.2, and 0.3 % by weight. The constant geometrical parameters such as pitch ratio (P/e = 6), height ratio (e/Dh=0.1571), and Reynolds number (Re = 5000) is considered for this study. A 2-D transient numerical analysis using the RNG k-ε turbulence model is performed for the melting behavior of NCPCMs inside the semicylindrical tubes. The incorporation of nanoparticles into the base PCM enhances thermal conductivity but reduces the latent heat of NCPCMs. Thus, it is observed that NCPCMs have a faster melting rate. The CuO based NCPCM shows a more quick and uniform phase transition compared to the Fe3O4, and Al2O3 based NCPCMs and reached their peak value at a higher mass fraction of 0.3. Furthermore, the heat transfer and melting fraction improves with increasing in mass fraction of nanoparticles. The phase transition process of CuO based NCPCM is approximately 1.9 times, and 1.01 times, 1.03 times faster as compared to the base PCM, and Fe3O4, Al2O3 based NCPCMs respectively.

Numerical simulation of melting heat transport mechanism of Cross nanofluid with multiple features of infinite shear rate over a Falkner‐Skan wedge surface

Numerical simulation of melting heat transport mechanism of Cross nanofluid with multiple features of infinite shear rate over a Falkner‐Skan wedge surface

Significances of melting heat transfer and bioconvection phenomena in nanofluid flow over a three different geometries

This study addresses the numerical investigation of the steady and two-dimensional flow of magnetohydrodynamic nanofluid containing motile microorganisms over three distinct configurations: a wedge, a plate, and the stagnation point of a flat plate. The impacts of activation energy, melting phenomena, thermophoresis, and Brownian motion are taken into account. The dimensionless form of the governing coupled nonlinear partial differential equations is obtained by using similarity transformations. The system of ordinary differential equations is numerically solved using the “bvp4c” solver in MATLAB, and obtained results are also validated with an analytical approach Optimal Auxiliary Function Method (OAFM). Skin friction, heat, mass and motile microorganisms transfer rates are discussed through graphs and tables. Findings indicate that profile for Nusselt number enhances for higher inputs of melting parameter while Sherwood number lowers with increasing inputs of activation energy parameter. An improving pattern of velocity profiles is magnificent for stagnation point flow [f(η = 1) = 0.943711] compared to wedge [f(η = 1) = 0.915698]and horizontal plate [f(η = 1) = 0.868617]with respect to wedge angle parameter keeping velocity ratio parameter A < 1. For the wedge surface, the temperature profiles decrease [θ(η = 1.5) = 0.933075, 0.895245, 0.858931] for increasing inputs of radiation parameter (2.5 ≤ Nr ≤ 4.5) while motile microorganism profiles enhance [χ(η = 1.3) = 0.532505, 0.621569, 0.690635] with bioconvection Schmidtt number (0.3 ≤ Sb ≤ 0.7) respectively. Furthermore, it was found that, as velocity slip parameter increases then velocity of fluid also improves over a plate, wedge, and stagnation point of a flat plate considering velocity ratio parameter A < 1 .