Heat Transfer Devices Research Articles

TASA formulation for nonlinear radiative flow of Walter-B nanoliquid invoking microorganism and entropy generation

Recent scientists and engineers have keen interest for nanomaterial flow across the globe. It is because of the fact that nanomaterials possess innovative characteristics that have gained considerable attention for their involvement in medicine, automobiles, metal spinning, heat transfer and storage devices, power generation, renewable energy and many others. Heat transfer rate has key role regarding finishing and quality of end product. With such consideration the present communication analyzes magnetohydrodynamic bioconvective flow of Walter-B nanoliquid. Flow is generated by stretching surface. Gyrotactic microorganisms in presence of first order reaction is discussed. Energy expression comprises Brownian movement, magnetohydrodynamics, thermophoresis, thermal radiation and dissipation characteristics. Innovative features (random movement and thermophoresis) of Buongiorno's model are deliberated. Entropy minimization rate is under consideration. Soret effect in first order reactive flow is considered. Bejan number is calculated. Dimensionless ordinary expressions are developed through suitable transformations. Optimal homotopy analysis method (OHAM) is invoked for convergence purposes. Total and individual residual errors have been computed through OHAM which guarantees the solutions convergence. Graphical analysis for entropy rate, microorganism field, liquid motion, temperature, Bejan number and concentration is arranged. In addition, the analysis for skin friction, motile density number and Nusselt and Sherwood numbers is organized. Here velocity and Bejan number decreased against larger magnetic field whereas opposite scenerio witnessed regarding thermal field and entropy rate. Decrease in liquid motion occurs through viscoelastic variable while an increasing effect seen for thermal transport rate. Higher Prandtl number lead to intensify the thermal transport rate. Nusselt number and entropy rate for radiation have similar response qualitatively when compared with concentration through higher Soret number.

Thermal Performance Investigation of Vapor Chamber Under Partial Heating and Different Heat Flux Conditions: Effects of Inclination Angle

Abstract The need for cooling technologies increases tremendously with raising demand on the powerful and compact electronics. There, it pushes the research and technology to the new investigations on varying heat transfer mechanisms and devices. While one of these devices is vapor chamber (VC), an experimental study has been carried out to investigate the heat transfer performance of a VC under partial heating, varying heat fluxes, and different inclination angles for different temperatures, in the current study. For this purpose, a VC with a dimension of 90 mm × 90 mm × 3 mm is evaluated via its resulting thermal resistance, performance, and the temperature distribution over the VC surface. There, the limited effect of inclination angle is observed on the performance, while the highest change is obtained with decreasing local heating surface area, thus increasing heat fluxes. Moreover, this trend is seen almost similar with a reasonable shift up or down according to the different temperature differences.

Experimental characterisation and visualisation of a novel two-phase flexible heat transfer device

The importance of passive Flexible Heat Transfer Device (FHTD) in electronic cooling or space applications lies in their ability to provide efficient, reliable, and adaptable thermal management solutions. Heat transfer enhancement studies pertaining to FHTD developed to meet the thermal management demands of futuristic flexible electronic devices are presented in the current work. The possibility of extending the heat transport limit of FHTD beyond 24 W by limiting the maximum operating temperature to 60 °C is discussed. The superior performance of FHTD at varying heat loads from 5 W to 40 W at 45°and 90°bending angles is brought out compared with existing heat transfer devices like Flexible Heat Pipe (FHP) and copper thermal straps. The performance is reported in thermal resistance and equivalent thermal conductivity. A commercial dielectric liquid is used as a working fluid in FHTD to enhance the heat transfer limit employing phase change. The evaporator and condenser sections of the flexible section are made transparent to visualise the boiling and condensation phenomenon. Under steady-state operation at a 45°bending angle, The FHTD demonstrates a minimum thermal resistance of 0.73 K/W and a peak effective thermal conductivity of 8172 W/m K. The heat transfer coefficient ranges from 200 to 700 W/m2 K, consistent with values reported for heat pipes in the literature. Additionally, the study explores the impact of modifying the external surface texture to create more nucleation sites, thereby enhancing the performance of the FHTD. The results show that the laser-textured surface on the heat pipe condenser effectively reduces the onset of nucleate boiling for dielectric fluid by 3.5 °C and decreases the maximum temperature of the evaporator by 4.5 °C. The present work dictates the fundamental baseline for possible design choices of futuristic passive flexible heat transfer devices.

Thermal management and power generation characteristics in a bifurcating channel by using a piezo-embedded inclined elastic fin assembly during turbulent forced convection of ternary nanofluid

Numerous engineering systems use piezoelectric energy harvesters (PE-EHs), which have several benefits including low cost, simplicity, better power density, and ease of installation. They can be used in different applications for energy harvesting and different external sources such as wind and vortex induced vibrations due to fluid–structure interaction can be utilized. This study uses a unique elastic fin PE/EH assembly for power generation, thermal management, and flow control in a bifurcating channel. Performance of the system is improved by using ternary nanofluid in the channel cooling system. Galerkin weighted residual FEM with ALE is used as the solution method. The convective heat transfer performance and power generation by the EH device are investigated in relation to the varying following parameters: Reynolds number (Re between 10000 and 30000), PE-EH inclination (γ between 0 and 60), fin horizontal location (xf between −H and H), and nanoparticle loading in the base fluid (ϕ between 0 and 0.03). The vortex size and distribution near the junction are significantly influenced by the fin inclination and horizontal location of the fin assembly within the bifurcating channel. When varying other parameters of interest, using nanofluid at the highest loading results in significant deflection of the fin assembly and power generation within the PE-EH. Enhancement factors (EFs) for power generation becomes 15.6 and 39.8 when cases of lowest and highest Re are compared with pure fluid and nanofluid while they are 2.93 and 3.38 for thermal performance improvements. Fin inclination of γ=30 is found as the optimum inclination for achieving the highest power from the assembly. Higher inclination of elastic fin/PE-EH assembly results in cooling performance deterioration while average Nu reduces by a factor of 2.94 by varying inclination from γ=30 to γ=60 with nanofluid. For power generation, effects of using nanofluid with varying inclination is significant and EF becomes 252 from γ=0 to γ=30. There are opposing tendencies for the device’s power generation and cooling performance enhancement when the fin’s horizontal placement is changed. EF for average Nu is 7.25 for varying fin location. As the loading of nanoparticle inside the base fluid increases, the average Nu and generated power exhibit non-linear rising characteristics. Polynomial type correlations are provided for the average Nu and power from the device by varying elastic fin assembly inclination and nanoparticle solid volume fraction. Potential of using hybrid nanofluid in PE-EH embedded thermo-fluid system is shown. The design, development, and optimization of self-sufficient power production systems that may be used to various thermo-fluid systems, such as electronic cooling and thermal control in a range of heat transfer devices, may benefit from the findings.

ВЛИЯНИЕ ТЕПЛОФИЗИЧЕСКИХ СВОЙСТВ ТЕПЛОНОСИТЕЛЕЙ НА ПРОЦЕСС ТЕПЛООБМЕНА В ЗАМКНУТЫХ ДВУХФАЗНЫХ ТЕПЛОПЕРЕДАЮЩИХ СИСТЕМАХ

The analysis of low-temperature heat carriers (ozone-safe freons) properties for use as heat carriers in thermosyphon elements has been carried out. The most significant thermophysical properties of heat carriers that affect the intensity of heat exchange in closed two-phase heat-transfer devices have been determined. The calculation of the FOM quality index of the heat carrier for the selected freons is given. The dependence of the thermal resistance of the thermosyphon element on the supplied heat load is established. Recommendations are given for choosing a heat carrier for two-phase heat-transfer elements

Enhancing Capillary Pressure of Porous Aluminum Wicks by Controlling Bi-Porous Structure Using Different-Sized NaCl Space Holders.

Capillary pressure and permeability of porous media are important for heat transfer devices, including loop heat pipes. In general, smaller pore sizes enhance capillary pressure but decrease permeability. Introducing a bi-porous structure is promising for solving this trade-off relation. In this study, the bi-porous aluminum was fabricated by the space holder method using two different-sized NaCl particles (approximately 400 and 40 μm). The capillary pressure and permeability of the bi-porous Al were evaluated and compared with those of mono-porous Al fabricated by the space holder method. Increasing the porosity of the mono-porous Al improved the permeability but reduced the capillary pressure because of better-connected pores and increased effective pore size. The fraction of large and small pores in the bi-porous Al was successfully controlled under a constant porosity of 70%. The capillary pressure of the bi-porous Al with 40% large and 30% small pores was higher than the mono-porous Al with 70% porosity without sacrificing the permeability. However, the bi-porous Al with other fractions of large and small pores did not exhibit properties superior to the mono-porous Al. Thus, accurately controlling the fractions of large and small pores is required to enhance the capillary performance by introducing the bi-porous structure.

Operation characteristics and limitations of small-diameter two-phase closed thermosyphon

Two-phase closed thermosyphon (TPCT) is a latent heat-based, high-efficiency heat transfer device primarily utilized in heat pipe heat exchangers in waste heat recovery (WHR) applications. Recently, there has been increasing interest in small-diameter TPCT due to thermal confinement issues and space and cost limitations of heat transfer devices. The nature of the two-phase flow and the resulting thermal performance of a small-diameter thermosyphon differ from that of a large-diameter thermosyphon, which is called the “confinement effect” of TPCT. In the present study, we experimentally explored the internal flow and heat transfer characteristics of TPCT with a very small inner diameter of 5 mm. Based on the Laplace length, which means the characteristic bubble size, four working fluids were considered: water, acetone, ethanol, and the HFE-7000. As a result, except for a specific condition where the degree of confinement and heat flux were very low, the shear force between the falling liquid condensate and upward vapor prevented the smooth circulation of working fluid inside the small-diameter channel. This caused local dry-out of the evaporator, resulting in the effective thermal conductivity of the TPCT being lower than that of the copper block.

Thermal performance analysis and optimization of a heat pipe-based electronic thermal management system using experimental data-driven neuro-genetic technique

Heat pipes are highly efficient heat transfer devices and are used widely to dissipate heat generated by electronic components, thereby maintaining their operating temperatures and preventing overheating. The present study deals with the thermal performance prediction of a cylindrical heat pipe (length 380 mm) based electronic thermal management system using steady-state experimental investigation. The experiments are conducted under varying operational conditions, including heat inputs (10–50 W), condenser cooling water inlet temperatures (288.15, 293.15, and 298.15 K), and flow rates (10, 25, and 40 LPH). The study shows that the evaporator temperature of the heat pipe consistently rises with the increase in heat inputs for all tested conditions. The lowest evaporator temperature (311.42 K) is noticed for the cooling water inlet temperature of 288.15 K across all heat inputs. Notably, at 10 LPH, the heat pipe supplied with cooling water at 288.15 K exhibits reductions of up to 1.47 % and 2.29 % compared to 293.15 K and 298.15 K, respectively. Similar trends are also observed at 25 LPH and 40 LPH. The heat pipe’s thermal resistance is lowest (0.95 K/W) at a cooling water inlet temperature of 298.15 K. At 10 LPH, there are reductions of 10.19 % and 5.62 % compared to 288.15 K and 293.15 K, and at 40 LPH, reductions are 15.66 % and 7.89 %. The heat pipe’s evaporator heat transfer coefficient also plays a significant role and is maximum for the cooling water inlet temperature of 288.15 K at a flow rate of 10 LPH. To understand the complex behavior of the heat pipe and for better prediction of its thermal performance, a neuro-genetic (experimental data-driven artificial neural network and genetic algorithm) optimization technique is considered in the study. This predicts the optimal combination of operating parameters (heat input, cooling water inlet temperature, and flow rate) to minimize the heat pipe’s evaporator wall temperature which is found to be 312.54 K at a heat input of 10 W, flow rate of 10 LPH, and cooling water inlet temperature of 289.14 K. These input combinations are further validated through the experiments and the error in the heat pipe’s evaporator temperature is found to be 0.66 % only. Overall, this neuro-genetic technique underscores the importance of optimizing operational parameters for enhanced heat pipe performance and offers valuable insights for electronic cooling systems.

Dry spot propagation during boiling crisis on thin metal heaters

This work presents the results of an experimental investigation aimed at elucidating the role of heater-side parameters on the growth of an irreversible dry spot during the boiling crisis of FC-72 on thin metal foils. A two-sided funnel shape of the heater is adopted to induce the occurrence of the boiling crisis in the middle of the foil and capture the expansion of the critical dry patch through high-speed infrared thermometry. In agreement with pre-existing literature, critical heat flux values achieved during this experimental campaign are shown to increase with bulk subcooling, thermal effusivity, and thickness of the heater. The transient temperature field at the boiling surface is used to capture the spatiotemporal evolution of the dry spot and investigate the effect of heater’s parameter on dry spot propagation. Results collected in this work show that the growth of an irreversible dry patch is strongly affected by the heat diffusion process occurring within the thin heater. The dry spot propagation rate is found to be proportionally correlated with the thermal diffusivity of the heater and the volumetric heat dissipation rate achieved at the boiling crisis, the latter being inversely proportional to heater’s thickness. These results provide important insights into the dryout dynamics related to the boiling crisis in thin wall heat transfer devices. Nevertheless, they open questions about the role of fluid thermophysical properties, that still deserve to be studied in detail.

Multiple slip nonlinear radiative bioconvective flow of nanofluid with variable thermal conductivity

Owing to the improved thermal applications of nanomaterials, various applications have been suggested in various era of engineering including heat transfer devices, chemical processes, thermal management devices, electronic cooling etc. The aim of current investigation is to presents the bioconvective flow of nanofluid with applications of multiple slip effects. The motivations for considering the slip effects for heat and mass transfer analysis are associated to its significance in the petroleum sciences, extrusion processes, oil recovery and plasma physics. The nonlinear thermal radiation effects and chemical reaction consequences have been attributed. In contrast to traditional investigations, the thermal conductivity of nanofluid have been assumed to be temperature dependent. Following the assumptions of dimensionless variables, a system of nonlinear differential equations is obtained. The shooting technique is employed for computing the numerical simulations. The accuracy of solution is ensured. The physical assessment of problem is incorporated in view of involved parameter. It has been claimed that interaction of slip effects enhances the heat and mass transfer effects. Change in microbes density slip parameter leads to improvement in the microorganisms profile. Moreover, local Nusselt number and Sherwood number reduces for slip parameters. Current results present significance in heat transfer systems, thermal engineering, chemical engineering, fertilizers, biofuels etc.

Analysis of peristalsis transport in flow of non-Newtonian fluid with modified Darcy’s law

Nanofluids present novel applications in various era of engineering and medical sciences like lubricants, medication delivery, cancer treatment, and microchip cooling. Investigating the peristaltic transport of a magnetohydrodynamic (MHD) Williamson nanofluid model in a horizontally asymmetrical channel is the main goal of this article. A porous medium allows the flow to take place according to the revised Darcy’s law. Hybrid nanoparticles based on aluminum oxide are used to improve the thermal properties. The classical aspects with implementation of Buongiorno approach namely thermophoretic effects and Brownian impact is elaborated. The extension in heat equations is proceeded with utilization of Joule heating and viscous dissipation outcomes. There are no-slip conditions linked to the channel borders. By adhering to the lubricating strategy and employing the homotopy perturbation method, the issues are resolved. Graphs and tables are used for physical analysis of the relevant parameters. It is examined that velocity profile enhances due to Darcy parameter in both channel walls. The temperature profile for hybrid nanofluid increases for Brinkman number. Low concentration profile is claimed for activation energy parameter. Current results incorporate the applications in thermal engineering, nuclear systems, roller pumps, heat transfer devices, chemical engineering, etc.

Silicon-based microscale-oscillating heat pipes for high power and high heat flux operation

Microscale-oscillating heat pipes (micro-OHPs) have recently drawn interest for electronic cooling applications due to their compact size and passive operating mechanism. The occurrence of dryout in OHPs, however, at which the working liquid no longer wets the evaporator, limits the maximum operating cooling power, preventing their integration for direct cooling of high heat flux semiconductor chips. Here, we report on high power and high flux operation of silicon-based OHPs by using microchannels with hydraulic diameters of ∼200 μm. Particularly, a micro-OHP with 100 μm channel height is shown to effectively operate at 210 W using a dielectric working fluid, corresponding to an unprecedented cooling power density of 145 W/cm2, without dryout. A distinctive oscillating mode with highly periodic bulk circulations occurs at high heating power and can provide efficient heat dissipation. The flow speed of the liquid under this bulk circulation mode can be as high as 10 m/s. The empirical relationships between the heat transfer rate, oscillating frequency, and device temperatures are studied.

On the design of manifolds for parallel channel systems

In the design of high-performance heat and mass transfer devices such as liquid-cooled heat sinks, catalytic reactors, and catalytic convertors, parallel mini/microchannels are favored owing to their special potentials. Offering low pressure drop, providing high transfer surface area to volume ratio, and being easy to manufacture and optimize have been drawing thermal and chemical engineers attention to parallel channels for past decades. When working with parallel channels, the challenge of flow maldistribution is commonly faced which decreases their efficiency significantly. System total pressure drop and flow uniformity are two parameters that determine the system performance. In the present study, a variety of practical ideas, aiming to enhance parallel channels performance, are studied numerically. Inventive manifold designs with high hydraulic performance are created through the course of this study. The results of these designs are compared with basic conventional designs which show substantial enhancement. Analyzing less successful designs lead us to deep understanding of fluid dynamics in parallel channel heat and mass transfer devices.

Correlation to predict thermal characteristics of pulsating heat pipes with long evaporator section

In terms of employing closed-loop pulsating heat pipes as heat transfer devices in solar water heaters, the evaporator should be extremely long according to the length of the solar collector. However, there is a noticeable shortage of Semi-Empirical Correlations for predicting the thermal performance of extra-long closed-loop pulsating heat pipes utilized for heat absorption within solar collectors. The primary objective of this study was to formulate a Semi-Empirical Correlation specifically designed for predicting the thermal efficiency in extra-long closed-loop pulsating heat pipe configurations. This study extensively examined the thermal efficiency of a comprehensive design of closed-loop pulsating heat pipe samples when implemented in an evacuated-tube solar water heater system strategically designed for individual households. The specified maximum length for the evaporator section of the closed-loop pulsating heat pipes is set at 1.50 m, in contrast to the conventional design, which typically features an evaporator section of approximately 0.15 m. Furthermore, the investigation encompasses a number of sets, varying as one, two, and four. Therefore, a Semi-Empirical Correlation derived from the experimental data concerning seven pertinent non-dimensional parameters is presented, demonstrating a standard deviation percentage of 4.4 %. Among these parameters, the number of sets emerged as the most influential, inducing a maximum percentage change in the heat rate of water of 20.47 %. Moreover, compared with other studies utilizing pulsating heat pipes in solar water heaters, the correlation exhibited a 1.52 % error. These findings suggest that the developed Semi-Empirical Correlation is a valuable tool for predicting the thermal performance of an extra-long closed-loop pulsating heat pipe. It is particularly well suited for estimating the thermal behavior of closed-loop pulsating heat pipes with extended configurations, showcasing its enhanced accuracy and relevance in capturing the distinction of heat transfer in extra-long closed-loop pulsating heat pipe systems.

Thermo-magnetic convection of MHD Casson fluid in a wavy triangular porous cavity with embedded a cold inverted triangle obstacle

The design of enclosures is crucial in thermal engineering applications and technologies, encompassing areas such as electronics, heat transfer devices, power reactors, heating systems, solar panels, and nuclear power plants. Thermal efficiency in microchannels is optimized and improved by using triangular enclosures with varying aspect ratios. Specifically, the purpose of these triangular enclosures with cool cylinders is to reduce energy loss in nanoscale thermal sinks and thermal exchange devices. The current study aims to explore the thermal radiation effects on magnetohydrodynamic MHD Casson fluid flow within a wavy triangular cavity that includes an embedded cold inverted triangle. The inner inverted triangle is kept at a lower temperature, while the wavy bottom wall of the outer triangular cavity acts as an isothermal heat source at a higher temperature. The numerical solution for this mathematical model is obtained using the open-source finite element software COMSOL. In this study, the wavy triangular enclosure is analyzed for key parameters such as Casson parameter β , Hartmann number Ha , Rayleigh number Ra , numbers of undulation N , radiation Rd and inclination γ . The study presents the local distribution of streamlines, velocity profiles, isothermals, and entropy production, along with the Nu avg . The results reveal the rate of heat transport and total entropy production raise with the increasing number of undulations N and the Casson parameter β , while they decrease with increasing Hartmann number Ha . The number Nu avg rises with the increasing radiation parameter Rd and Rayleigh number Ra . The maximum stream function is observed at an inclination angle of 60 ° .

Evaluation of innovative thermal performance augmentation techniques in heat sinks & heat pipes: Electronics & renewable energy applications

Heat sinks and heat pipes have vast applications including industrial domains requiring high heat flux. Due to numerous uses of these heat transfer devices, there have been great advancement in this area through innovation. This study focuses use of nanofluids and hybrid nanofluids for thermal performance enhancement of heat pipes and heat sinks. There are five different arrangements finless sintered copper wicked heat pipe, water based TiO2 filled heat pipe, TiO2 and SiO2 based hybrid nanofluid filled heat pipe, water cooled cylindrical pin finned heat sink and Fe2O3 and TiO2 hybrid nanofluid cooled heat sink. There are two test rigs one for testing heat pipe configurations and other for heat sinks. All the five elements are tested at constant heat flux ranging from 900 W/m2 to 3600 W/m2, in four equal steps. It’s observed that nanofluids play a very significant role in thermal performance augmentation, the affect is even more significant in heat pipes compared to heat sinks. Interestingly, nanofluids based heat pipes are proved more significant for high heat flux applications, although, nanofluid cooled heat sinks have slight better performance compared to the said but at a higher expense of weight, auxiliaries, space and cost. At 3600 W/m2 nanofluid based heat pipes have 33 % lower thermal resistance compared to water cooled heat sink. Therefore, nanofluid based heat pipes are primarily significant unless use of heat sink deemed dire. Nusselt number of heat sink is calculated at various heat flux and at variable mass flux conditions and found increasing with both parameter.

Performance of a novel loop heat pipe coupled with micro vapor-driven jet injector – An experimental and numerical study

Loop heat pipe (LHP) is an efficient phase-change heat transfer device which has been widely applied in cooling high-power electronics on ground and in spacecraft. In previous work, a novel LHP coupled with vapor-driven jet injector (VDJI) has been proved to be feasible and shows excellent performance, namely LHPI. However, due to the lack of pressure data during LHP operation, the coupling mechanisms of VDJI and LHP remain unknown. Especially, the heat-mass transfer between high-speed vapor and subcooled liquid inside VDJI, which has great influence on the LHPI, need to be investigated to guide the design of the LHPI. In this paper, the start-up process, steady-state operation characteristic of LHPI and internal flow field of VDJI were investigated experimentally and numerically. By using the pore-forming sintering and integrated sintering method, the bi-porous wick was prepared and embedded on the base plate surface of evaporator, which brought a significant improvement in its performance. The results indicated that the LHPI could operate under a power of 600 W (50.0 W/cm2) without dry-out. Maintaining the heating wall temperature within 85 °C, the minimum thermal resistance of the LHPI with bi-porous and integrated sintered wick was below 0.18, and the maximum heating power can reach up to 404 W, which are 60% lower and 52.5% higher than mono-porous wick, respectively. In addition, four operation modes of VDJI were classified as low-efficiency mode, normal-injection mode, restricted expansion mode and superheated mode. The operation modes of VDJI had great influence on the performance of LHPI. In normal-injection mode, the entrainment ratio of VDJI exceeded 100, which resulted in the lowest thermal resistance of LHPI. For long-term operation of LHPI, the VDJI is suggested keep operating in normal-injection mode. Moreover, by using 3D numerical simulation method, the internal flow structure of the VDJI was obtained to gives an insight into mechanisms of these four operation modes. The numerical results showed the profile of compression waves and confirmed the existence of condensation shock wave in VDJI.

Applications of pulsating heat pipe (PHP) as an efficient heat transfer device: a review of recent developments

Applications of pulsating heat pipe (PHP) as an efficient heat transfer device: a review of recent developments

Effect of Wavy Interface on Natural Convection in Square Cavity Partially Filled with Nanofluid and Porous Medium using Buongiorno Model

nvective heat transfer improvement from wavy surfaces presents a new solution in industrial engineering for composite materials, including porous medium, and nanofluids to address the wavy irregular surfaces in heat transfer devices such as a wavy solar collector, energy absorption and filtration, thermal insulation, and geothermal power plants. This technique enables the performance of engineering applications. The numerical study is performed to examine the effects of a wavy interface separating two layers in the enclosure on heat exchange rates. This paper investigates numerically the natural convection flow in a square cavity partially filled with nanofluid-porous layers separated by a wavy horizontal interface. The left and right walls of the cavity are maintained at constant hot and cold temperatures, whereas the other walls are adiabatic. The Buongiorno model is used to describe nanofluid motion, taking into account the brownian and thermophoresis effects in the cavity. The Galerkin finite element method was applied to solve the differential governing equations. The dynamic, thermal field and heat transfer have been analyzed for various parameters such as Rayleigh number (10^3 ≤ Ra ≤ 10^6), the amplitude of interface (0 ≤ A ≤ 0.1), and undulation number (0 ≤ n ≤ 9). The results reveal that the flow intensity induced by buoyancy forces is more significant in the nanofluid layer than in the porous layer, since the heat transfer is enhanced while the flow is not sensitive to variations in amplitude and number undulation, and accordingly, the decline of average Nusselt and Sherwood numbers is insignificant. The effects of controlled parameters on the structure of nanofluid flow, heat, and mass transfer rate are insignificant.

Machine learning methods for modeling nanofluid flows: a comprehensive review with emphasis on compact heat transfer devices for electronic device cooling

Machine learning methods for modeling nanofluid flows: a comprehensive review with emphasis on compact heat transfer devices for electronic device cooling