Subjects -> PHYSICS (Total: 857 journals)
    - ELECTRICITY AND MAGNETISM (10 journals)
    - MECHANICS (22 journals)
    - NUCLEAR PHYSICS (53 journals)
    - OPTICS (92 journals)
    - PHYSICS (625 journals)
    - SOUND (25 journals)
    - THERMODYNAMICS (30 journals)

THERMODYNAMICS (30 journals)

Showing 1 - 29 of 29 Journals sorted alphabetically
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26)
Applied Thermal Engineering     Hybrid Journal   (Followers: 41)
Araucaria. Revista Iberoamericana de Filosofía, Política y Humanidades     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 9)
Chemical Thermodynamics and Thermal Analysis     Open Access   (Followers: 7)
Condensed Matter Physics     Open Access   (Followers: 2)
Diffusion Foundations     Full-text available via subscription   (Followers: 4)
European Journal of Mechanics - B/Fluids     Hybrid Journal   (Followers: 5)
Experimental Heat Transfer     Hybrid Journal   (Followers: 17)
Experimental Thermal and Fluid Science     Hybrid Journal   (Followers: 34)
Fluids     Open Access   (Followers: 1)
Heat and Mass Transfer     Hybrid Journal   (Followers: 28)
Heat Transfer Engineering     Hybrid Journal   (Followers: 37)
High Temperature     Hybrid Journal   (Followers: 2)
HTM Journal of Heat Treatment and Materials     Full-text available via subscription   (Followers: 3)
International Journal of Thermodynamics     Open Access   (Followers: 11)
International Journal of Thermophysics     Hybrid Journal   (Followers: 7)
Journal of Thermodynamics & Catalysis     Open Access   (Followers: 6)
Journal of Chemical Thermodynamics     Hybrid Journal   (Followers: 4)
Journal of Low Temperature Physics     Hybrid Journal   (Followers: 8)
Journal of Non-Newtonian Fluid Mechanics     Hybrid Journal   (Followers: 16)
Journal of Thermal Science     Hybrid Journal   (Followers: 21)
Journal of Thermal Spray Technology     Hybrid Journal   (Followers: 5)
Journal of Thermodynamics     Open Access   (Followers: 7)
Journal of Thermophysics and Heat Transfer     Hybrid Journal   (Followers: 93)
Low Temperature Physics     Hybrid Journal   (Followers: 6)
Metal Science and Heat Treatment     Hybrid Journal   (Followers: 36)
Quantitative InfraRed Thermography Journal     Hybrid Journal  
Thermophysics and Aeromechanics     Hybrid Journal   (Followers: 6)
Similar Journals
Journal Cover
Heat and Mass Transfer
Journal Prestige (SJR): 0.448
Citation Impact (citeScore): 1
Number of Followers: 28  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1432-1181 - ISSN (Online) 0947-7411
Published by Springer-Verlag Homepage  [2468 journals]
  • Experimental study of multidimensional wire-plate/sintered hybrid mini
           heat pipes for electronics

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      Abstract: Abstract The experimental study concerning new two and three dimensional mini heat pipes, proposed for cooling electronic components in printed circuit boards is presented. These heat pipes can capture the heat from electronic components and conduct it to the cabinet wall, through the narrow spaces available between boards. As the location and dissipation of the electronic components vary, several different heat pipes are necessary for a complex electronic equipment, which should operate at different temperatures and orientations. A hybrid wick structure, composed by sintered copper powder and wire-plate technologies along the device are proposed. Four different types of hybrid mini heat pipes, in up to three generations, were designed and constructed, using diffusion bonding fabrication technique. Two different testing setups were developed. First, the thermal performance of the hybrid heat pipes was accessed, resulting in the selection of the appropriated working fluid and its volume. Second, the devices were tested in rigs that mimic actual electronic equipment geometries and operational conditions. The several hybrid multidimensional heat types worked well, even against gravity. Besides, the present work shows that the wire-plate wick structure, up to this date considered only in academic studies, resulted in very flexible heat pipes, able to start up easily, in several adverse geometric and gravitational conditions, especially when combined with more conventional technologies, such as sintered porous media. Besides, the fabrication process developed that includes diffusion bonding, can be considered a novelty.
      PubDate: 2024-03-02
       
  • Application of a phase change numerical model to the simulation of
           freezing and thawing of wrapped foods

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      Abstract: Abstract The process of heat transfer is one of the most important issues in the food industry and plays a crucial role in the storage of frozen foods. The main objective in this field is to extend the storage time, which can be achieved by limiting the heat transfer between the ambient air and the frozen food product. In this paper, the authors applied a numerical model of the phase change process to simulate the freezing and thawing process of a package wrapped with compressible multilayer polymer thermal insulation. The model was solved in COMSOL Multiphysics program and verified with experimental results with satisfactory agreement. Based on the performed simulations and experiments, it was proved that the freezing time of the tylose package is almost the same regardless of the applied film, while the thawing time of the package strongly depends on the type of film—transparent, opaque or metallized. The use of transparent film allows to extend the maximum thawing time of food products by 2 times, the use of opaque film—by about 3.7 times, and the use of metallized film—by about 4.1 times.
      PubDate: 2024-03-01
       
  • Optimized combustor performance based on the combination of bluff body and
           porous media

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      Abstract: Abstract The direct emission of coal mine methane caused serious environmental pollution and resource waste. To improve the methane utilization, the porous media burner was regarded as an efficient method. In this paper, the bluff body was proposed to combine with porous media to optimize the combustion characteristics. The effects of bluff body position, size and shape on the temperature distribution and gas emission were studied at different operating conditions. The results indicated that the position of the bluff body greatly influenced the combustion characteristics, and the maximum temperature of 1295 K was obtained at the position of 62 mm. The increase of the bluff body diameter promoted the flame moving to the burner outlet. And the combustion temperature increased first and then decreased when the bluff body height increased. Moreover, the CO and NOx emissions at the height of 20 mm reached 31 and 16.8 ppm respectively. The combustion temperature was significantly improved by increasing the equivalence ratio and velocity. Compared with the single porous media, the addition of the bluff body increased the combustion temperature and reduced the CO emission by 11%.
      PubDate: 2024-03-01
       
  • Enhanced heat transfer performance of silver Nanofluids as coolants in a
           helical Shell and tube heat exchanger: an experimental study

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      Abstract: Abstract Silver nanofluids have recently emerged as a promising coolant for enhancing heat transfer performance. This study experimentally investigates the heat transfer characteristics of silver nanofluid in a helical shell and tube heat exchanger. Spherical silver nanoparticles of 143 nm mean diameter were synthesized using a chemical reduction method and characterized comprehensively. The nanofluid was utilized as the tube-side coolant at volumetric concentrations of 1.5% and 2.5%, with its effectiveness compared to water. The impacts of concentration and fluid flow rate on heat transfer coefficient and effectiveness were evaluated under varying conditions. Results showed improved heat transfer performance using silver nanofluid, with the maximum enhancement at 2.5% concentration. The heat transfer coefficient and effectiveness increased with higher flow rate, demonstrating the importance of optimizing fluid flow conditions. This study provides new insights into harnessing silver nanofluids for thermal engineering applications and quantifies the effects of concentration and flow on the viability of silver nanofluids as efficient coolants in heat exchangers.
      PubDate: 2024-03-01
       
  • Thermal properties and water content of two tropical wood species as a
           function of the air relative humidity.

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      Abstract: Abstract This work aims to use experimental data from thermal characterization and adsorption/desorption isotherms of two tropicals woods species (Ayous and Tali) to propose an empirical model of thermal conductivity as a function of air relative humidity. A static gravimetric method was used to determine the adsorption isotherms of Tali and Ayous at 30 °C, and 40 °C. The GAB, Henderson and Nelson models were used to predict the isotherms. Exponential models of thermal conductivity and volumetric heat capacity with air relative humidity were proposed. The influence of hysteresis phenomenum was studied on these properties. The reliability of the developed empirical correlation between thermal properties and air relative humidity was evaluated by comparing the experimental and predicted curves. The relative errors were less than 8% for both Ayous and Tali. The correlation coefficients obtained were greater than 99% for both species in adsorption and desorption. There was also an increase in the equilibrium water content of both species with the increase in water activity at constant temperature. The correlation coefficients between GAB model and sorption experimental data were lower than 99% when Ayous was subjected to a temperature of 40 °C in adsorption and Tali to a temperature of 40 °C in desorption.
      PubDate: 2024-03-01
       
  • Thermal analysis of a novel solar collector coupled in series and parallel
           connection based on honey-comb conjecture

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      Abstract: Abstract A potential solution to environmental problems associated to the use of fossil fuels and the exploitation of natural resources for energy production is the development of renewable energies with greater capacity, adaptability and integration, as well as their use for the improvement of this systems. Researchers turned their attention to biological and natural processes such as honeycombs at a structural level to increase the mechanical properties of various technologies. This investigation shows the results of the thermal analysis of a novel solar collector designed based on a Honey-Comb conjecture studied under different connections. Several structures were proposed considering a serial and parallel connections. Each one was designed and simulated in SolidWorks® software Flow Simulation. The study considers different boundary conditions as mass flow and solar radiation on the surface of the collectors. In the analysis, the maximum temperature was achieved at the highest solar radiation of 1050 \(W/{m}^{2}\) and the lowest flow mass of 0.052 kg/s. On the other hand, the peak performance of the heat thermal parameter in the whole study was achieved at solar radiation of 1050 \(W/{m}^{2}\) and the maximum mass flow of 0.17 kg/s. A honey-comb structure conformed by three collectors (AC1) shows an increase of around 187%, against a single collector (A0), comparing the other structures two collectors in series (AS1) and two collectors in parallel (AP1) connections the total increase in the useful heat obtained with AC1 was 52% and 49% respectively.
      PubDate: 2024-03-01
       
  • Study on the flow boiling of different media under supercooled conditions
           on surfaces with microstructures

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      Abstract: Abstract Previous studies have demonstrated that altering the surface structure can enhance heat transfer. In this study, a square micropillar array with a homogeneous structure was designed for a long rectangular channel with a hydrodynamic diameter of 10 mm. Deionized water and HFE-7100 were used as working fluids for the study. The effect of flow rate and subcooling degree on flow boiling heat transfer performance is discussed. The bubble behavior of two different media was compared by visualization experiments. The results show that the square microcolumn array will delay the ONB point by increasing the heat transfer area and disturbing the main fluid, and improve the overall boiling heat transfer performance by 2–3 times. It was found that HFE-7100 boils better under low heat flow density, but its stable nuclear boiling time is shorter. Furthermore, the effects of volume flow and subcooling on heat transfer performance vary significantly at different stages of the boiling process. Before the ONB point, an increase in volume flow will increase the heat current density by 88.9% and reduce the boiling heat transfer stability. After the ONB point, the effect of fluid flow on the boiling process weakens.
      PubDate: 2024-03-01
       
  • Heat transfer on impingement cooled meshing spur gears: Experimental
           comparison of into-mesh, out-of-mesh and inclined impingement methods

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      Abstract: Abstract Oil jet impingement cooling is the standard approach to cool high-speed high-power gears. The heat transfer between oil jets and gears is experimentally investigated in this paper. The three established methods of oil jet impingement cooling -into-mesh, out-of-mesh and inclined impingement on one of the gears- are studied. Heat transfer coefficients for these methods are experimentally determined. A loss correction approach is implemented for the evaluation of measurements. For the inclined impingement method, heat transfer on the non-impinged gear and the influence of meshing on the heat transfer coefficient are investigated. Gear meshing has an insignificant effect on the average heat transfer coefficient over the gear tooth. However, the spatial distribution of the heat transfer coefficient depends on the meshing configuration. Significant cooling on the non-impinged gear is observed with the inclined impingement method. The inclined impingement method is superior to the into-mesh and out-of-mesh methods at all measured operating points.
      PubDate: 2024-02-29
       
  • Comparison of thermal conductivities of polypropylene fibers and fibrils

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      Abstract: Abstract In this work, we compared thermal conductivities of polypropylene fibers and fibrils. The polypropylene fibers were melt spun, and oriented by solid-state drawing. Both wide-angle X-ray scattering and sonic velocity measurements were performed to determine the orientation of fibers. The thermal conductivities of fibers were measured via direct electrical heating method, and that of fibrils were measured via thermal bridge method. Our results show that the thermal conductivity of polypropylene fibers increases linearly with their sonic velocity. This suggests we can use the sonic velocity to characterize the thermal conductivity of semicrystalline polymers. Our results also indicate the average thermal conductivity of fibrils is close to that of fibers. This implies that the low thermal conductivity of polymer fibers is due to the low thermal conductivity of fibrils, instead of thermal resistance between fibrils.
      PubDate: 2024-02-26
       
  • Drying properties, color characteristics, microstructure, and modeling of
           ginger cubes dried using electrohydrodynamic, electrohydrodynamic-hot air,
           and hot air methods

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      Abstract: Abstract This study investigates the drying of ginger cubes using three different techniques: electrohydrodynamic drying, electrohydrodynamic-hot air drying, and hot air drying. The main objective is to assess how these drying methods affect drying times, effective diffusion coefficients, color, and microstructure. Additionally, the study includes fitting ten different thin-layer models to the experimental data for mathematical analysis. It was observed that increasing temperature and voltage values led to a reduction in the drying times of the ginger samples. After conducting statistical tests, it was determined that the Midilli et al. and Wang and Singh models were the most suitable for describing the experimental drying curves. Effective diffusion coefficient values increased with the rise in temperature and voltage values. The L* values of the dried ginger samples decreased due to temperature and voltage applications. Notably, ginger samples dried using the electrohydrodynamic method exhibited better preservation of their original appearance, particularly in terms of microstructure and starch particle integrity, compared to other drying methods. The findings of the study suggest that integrating electrohydrodynamic technology with hot air drying reduces overall drying time. This innovative approach shows promise for producing high-quality end products in the future.
      PubDate: 2024-02-26
       
  • Energy correlation of heat transfer for drag reduction surfactant solution
           in a double pipe heat exchanger

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      Abstract: Abstract In the present study, the effects of surfactant solutions on pressure drop properties and heat transfer characteristics in a double pipe heat exchanger have been investigated. An ionic surfactant (SDS) and two nonionic surfactants (NP-10 and Tween 80) solutions with 0.2 wt% are utilized at different flow rates. The results show that pressure drops for surfactant solutions are lower than those for water at equivalent flow rates. NP-10 demonstrates high drag reduction values, reaching a maximum of approximately 15%, whereas Tween 80 has lower drag reduction values, which vary according to the flow rate. Besides, Nusselt number for water in this study reveals a satisfactory agreement with the predictions derived from the Dittus-Boelter equation with a difference of 2.1%. While NP-10 and Tween 80 addition cause the Nusselt number to decline, SDS does not significantly alter it when compared to water. Energy correlations with high R2 values have been developed using experimental data for water and surfactant solutions. Furthermore, enhancement factors (η), the ratio of heat transferred at constant pumping power with and without surfactant, have been calculated. The η values vary within a range of 0.8‒1.1 depending on the flow rate, and for SDS solution, these values are above 1 when the Reynolds number is in the range of 13000–25000. In the case of NP-10 and Tween 80 solution, the η values are below 1 for the whole flow rate range.
      PubDate: 2024-02-23
       
  • Investigation of the hydrodynamic and thermodynamic behavior of the liquid
           jet quenching process

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      Abstract: Liquid jet quenching of metals is typically adopted to achieve specific material properties of metals, thereby making them suitable for advanced engineering applications. In this process, a metal plate is heated and cooled rapidly by impinging water jets. The temperature history during cooling leads to a microstructural transformation thereby improving the material properties such as hardness. During liquid jet quenching, since the plate surface temperature is above the Leidenfrost temperature, the boiling heat transfer dominates. This is associated with an intense cooling and water vapor generation, where the Leidenfrost effect impedes the immediate wetting of the surface. The resulting uneven cooling over the plate surface tends to potential deformation and cracking. To control this process, a detailed understanding of the spatial and the temporal heat transfer behavior is imperative. Experiments in this context are limited and therefore investigating the conjugate heat transfer process is to be combined with a multi-phase numerical model. The two-phase numerical model based on the Euler-Euler approach is developed and validated to simulate the jet quenching of a stationary plate considering all the boiling regimes within a single framework. This model consists of two phases, the liquid water which is the continuous phase (primary) and the water vapor modeled as the dispersed phase (secondary). In this study, a circular water jet (tap water) impact is considered and the plate materials under investigation are aluminum alloy (Al-alloy) and stainless steel (St-steel). Experiments are performed using infrared and high-speed imaging. The validated numerical model provides the technical parameters such as wetting front behavior, heat flux, HTC (heat transfer coefficient) etc. The influence of the jet Reynolds number and the plate material properties on the heat transfer is analysed. The study emphasizes that the plate material has a significantly higher influence on the heat transfer during jet quenching. Graphical abstract
      PubDate: 2024-02-19
       
  • Drying of Curcuma longa L. slices by refractance window: Effect of
           temperature on thermodynamic properties and mass transfer parameters

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      Abstract: Abstract Curcuma longa L. rhizomes (CL) are aromatic spices known for their natural dye properties. These rhizomes contain considerate quantities of nutrients and bioactive compounds. Nevertheless, due to their perishable nature, they necessitate water removal process. This research aims to evaluate the adequacy of the analytical model established by Dincer and Dost in 1995, using experimental data from the Refractive Window (RW) drying method, focusing on solid samples in the flat plate configuration of Curcuma longa L. A comparative analysis will be carried out with the model devised by Crank in 1975, which relies on the traditional solution of Fick's second law. The primary objective is to determine the mass transfer parameters and the thermodynamic characteristics relevant to the drying procedure. The drying process for the samples was observed to be relatively rapid. In their natural state, the samples had a moisture content of 80.71 ± 1.12% (on a dry basis). According to the Dincer and Dost model, the moisture diffusivity ranged from 0.85 × 10–8 m2 s−1 to 2.15 × 10–8 m2 s−1, and the mass transfer coefficient varied from 1.60 × 10–6 to 1.12 × 10–6 m s−1. The entropy value (ΔS) obtained was negative (ΔS < 0). The thermodynamic properties indicated a non-spontaneous process with positive values for enthalpy and Gibbs free energy, along with negative values for entropy.
      PubDate: 2024-02-17
       
  • Investigation evaluation of thermo-hydraulic flow and heat improvement in
           a 3D circular corrugated pipe based on response surface method and Taguchi
           analyses

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      Abstract: Abstract Current research is investigating the effect of different tube geometries on flow patterns and thermal performance. Perform numerical simulations and thermo-fluid couplings. Calculation results are calculated and the solution uses both flow transport and thermal correction. Results are compared and validated using experimental results. Hydraulic and heat flow behaviors in all corrugated tubes are studied and discussed under various constitutive parameters of position and shape. The turbulent fluid flow in these tubes is modeled using 3D numerical flow domain simulations and the optimization of the multilens algorithm is analyzed. The effects of various geometric design parameters such as ring diameter, spacing between each well ring, and number of well rings around the tubing spacing of the rings were analyzed using Response Surface Methodology (RSM) and Taguchi Method (TM). Analyzed. be studied. The effects of changes in flow structure, such as velocity magnitude and radial velocity, and velocity magnitude and radial velocity profiles in different configurations, are studied. An experimental design strategy using the Taguchi method (TM) is chosen according to the variance of the orthogonal L16 sequences. Optimization results show that higher differential pressure values are related to shaft diameter. Therefore, the number of corrugated rings has a great effect on the heat transfer rate and temperature difference. Various configurations of Conduit Performance Evaluation Factor (PEF) increased the PEF value by more than 1.3.
      PubDate: 2024-02-15
       
  • Comparative investigation of R1270, R290, and R600a boiling in microfin
           and smooth tubes

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      Abstract: Abstract This study investigates the comparative analysis performance of three environmentally friendly refrigerants, R1270, R290, and R600a, in the context of flow boiling heat transfer (FBHT) and pressure gradients. The experiments employ copper microfin and smooth tubes, operating under varying conditions, including saturation temperatures (Tsat) of 6 and 15 °C, heat fluxes (HF) ranging from 13 to 30 kW.m−2, mass fluxes (MF) spanning 187 to 427 kg.m−2.s−1, and vapor quality from 0.1 to 1.0. Both tube types share identical dimensions - an outer diameter, inner diameter, and length of 7 mm, 6.14 mm, and 500 mm, respectively - facilitating a focused investigation into the impact of microfins on flow boiling characteristics. The results highlight noteworthy differences among the refrigerants, with the microfin tube exhibiting substantial enhancements in heat transfer coefficient (HTC), particularly pronounced with R1270 and R290. At the same time, the R600a demonstrates more HTC improvements than the smooth tube. Additionally, the microfin tube increases pressure gradients. The average enhancement factor (EF) for R600a, R290, and R1270 are 2.15, 1.95, and 1.9, respectively, while the average penalty factor (PF) for R600a, R290, and R1270 are 1.25, 1.3, and 1.35, respectively. Comparative analyses with established literature correlations validate the experimental findings.
      PubDate: 2024-02-15
       
  • Optimization method for compact heat exchanger cores with circular
           channels

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      Abstract: Abstract Geometry optimization aims to maximize heat transfer rate and minimize pressure drop attending to structural and fabrication constraints. The present work carried out the first optimization study of compact heat exchangers produced by selective laser melting (SLM) with circular channels. No optimization study investigated circular mini channels since most focus on semi-circular channels of printed circuit heat exchangers. Besides, since samples produced by selective laser melting present higher yield strength, it was possible to investigate a higher range of configurations. Analytical models of heat transfer and pressure drop, with structural analysis in finite element model were used in the optimization study. The analysis was conducted using genetic algorithms (NSGA-II) based on evolutionary and dominance concepts to evaluate different configurations. The results showed a strong relationship with the admissible stress limit, so a new study, using the properties SLM samples, was performed. Decision variables’ behavior was investigated among all the optimum solutions, besides stress constraint and flow type (cross and counter-flow), resulting in different optimal solutions of Pareto curves. The optimization provided heat transfer and pressure drop ratio from 1.2 kW/Pa to 12.5 kW/Pa. The optimized arrangements were compared with heat exchangers from the literature, demonstrating a 19% improvement in thermal performance and an 85% reduction in pressure drop.
      PubDate: 2024-02-14
       
  • Drying kinetics and mathematical modeling of shredded tobacco under hot
           air drying

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      Abstract: Abstract In the traditional tobacco drying process, there is often a problem of uneven drying, which is closely related to drying conditions such as air velocity and temperature. To better understand the drying characteristics of tobacco, its drying kinetic performance were experimentally studied and predicted in this paper. In the drying experiment, the range of air temperature and velocity is 20–60℃ and 0.95–4.93 m/s, respectively. The results show that the effective diffusion coefficient increases with the increase of air temperature and decreases with the increase of air velocity. The effective moisture diffusivity( \({D}_{eff}\) ) ranges from 2.077 × 10–7 to 9.136 × 10–7 m2/s. Additionally, the activation energy (Ea) is between 14.292 and 21.032 kJ/mol according to Arrhenius law. Among the six commonly used empirical correlations, the logarithmic model has higher prediction accuracy, but it has a prediction deviation of more than 20% in the later stage of drying. Based on the logarithmic model and the two models, a new prediction model of tobacco drying characteristics was proposed with a maximum relative deviation error of less than 1%.
      PubDate: 2024-02-11
       
  • Direct contact evaporation of a single two-phase bubble in a flowing
           immiscible liquid media. Part II: convective heat transfer coefficient

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      Abstract: Abstract The direct contact evaporation of n-pentane volatile liquid drop in a warm flowing immiscible liquid (water) has been investigated experimentally. A Perspex column with a 10 cm internal diameter and 100 cm active height was used in the experiments. N-pentane at its saturated temperature (~36 °C) and distilled warm water were utilised as a continuous and dispersed phase. The warm water, with three different Jacobs numbers (Ja), (Ja = 6.1, 23 and 46.3), flows from the top of the column and leaves from the bottom at three different Reynolds numbers (Re = 3250, 6500 and 9750). The evaporation of the drop while rising along the column was filmed with a Photron FASTCAM high-speed camera ( \(\sim\) 65,000 f/s). All images were analysed using AutoCAD, and the two-phase bubble, the vaporisation ratio \(\left(x\right)\) and the half-opening vapour angle \(\left(\beta \right)\) were measured. The convective heat transfer coefficient in terms of Nusselt number (Nu) was predicted based on the measured two-phase bubble radius through the experiments. The effect of Reynolds’s number (Re), Jacobs’s number (Ja), vaporisation ratio (x), and diameter ratio (B) on Nu were investigated. The experimental results revealed that Nu increased with time. The Re and Ja significantly affected the time-dependent Nu. Although the final Nu was nearly the same for all cases (Nu = 21), the higher the continuous phase Re, the higher the Nu, especially with the progress of evaporation \(\left(\tau \ge 70\right)\) . In addition, the results showed that Ja inversely influenced the average Nu, and the final value of Nu depended strongly on Ja. The higher the Ja, the lower the average Nu and the shorter the time for complete evaporation. In this regard, the dimensionless time \(\left(\tau \right)\) required for complete drop evaporation was about 38, 60 and 120 for Ja of 46.3, 23 and 6.1, respectively.
      PubDate: 2024-02-10
       
  • Experimental study on hydrothermal characteristics of shell and tube heat
           exchanger using phase change material-based hybrid nanofluid

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      Abstract: Abstract The shell-and-tube heat exchanger (STHX) is probably the most ubiquitous form of heat exchanger in many industrial settings. In the current investigation, various nanofluids (Al2O3, PCM, CNT, Al2O3+PCM, and Al2O3+CNT) at volume concentrations of 0.01% and 0.1% were used to test the hydrothermal performance in a STHX. This study aimed to investigate the influence of the Nusselt number and friction factor on the Reynolds number and the hydrothermal performance of STHX at various volume fractions. The execution of an experimental investigation accomplished this. The findings demonstrated that the pressure drop and heat transfer coefficient depend on the nanofluid's flow rate, that it is superior to DI water and improves with volume. The hi/∆p value rises for Al2O3 due to pressure drop impacting heat transmission, but it falls for phase change material (PCM) and Al2O3+PCM nanofluids. The hybrid nanofluid Al2O3+CNT flowing at 10lpm in the tube has a 15.60% greater friction factor and an average Nusselt number of 38.08% compared to the base fluid. The heat transfer coefficient, Nusselt number, pressure drop, and friction factor for Al2O3+PCM at 8.33lpm increase by 9.18%, 8.91%, 36.84%, and 5.98%, respectively, with an increase in volume concentration from 0.01 to 0.1%. Nanofluids that are either mono- or hybrid and contain PCM dispersion have a better heat transfer coefficient at low flow rates. The pressure loss increases with increasing flow rate because PCM particles raise dynamic viscosity.
      PubDate: 2024-02-08
       
  • Oscillating heat pipe performance in various gravity force implementing
           openFOAM code

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      Abstract: Abstract This study investigates the effect of gravity on the flow pattern and thermal efficiency of a single-loop oscillatory heat pipe. To simulate the influence of gravity, the deployment angles of the mechanism are varied (30°, 45°, 60°, and 90°). OpenFoam software is implemented to model boiling and condensation in the oscillating heat pipe, utilizing the volume of fluid (VOF) method. The evaporator is supplied with 55.5 W of heat power, the condenser wall temperature is maintained at 300 K, and the filling ratio of heat transfer fluid (water) is 40%. The findings revealed that decrease in gravitational force results in the thermal resistance be increased and the thermal performance of heat pipes be diminished. Expectedly, the best thermal performance in the oscillating heat pipe is observed in vertical mode, however, this study also examines the influence of reduced gravity. The simulation results show that the bubble pattern is first initiated by the bubble nucleation at the start of the heating process. Consequently, by bubble coalescence the slug and annular regimes can be observed. The phenomenological analysis of the dissolution, bubble coalescence, growth, and contraction observed in this study are discussed.
      PubDate: 2024-02-06
       
 
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  Subjects -> PHYSICS (Total: 857 journals)
    - ELECTRICITY AND MAGNETISM (10 journals)
    - MECHANICS (22 journals)
    - NUCLEAR PHYSICS (53 journals)
    - OPTICS (92 journals)
    - PHYSICS (625 journals)
    - SOUND (25 journals)
    - THERMODYNAMICS (30 journals)

THERMODYNAMICS (30 journals)

Showing 1 - 29 of 29 Journals sorted alphabetically
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26)
Applied Thermal Engineering     Hybrid Journal   (Followers: 41)
Araucaria. Revista Iberoamericana de Filosofía, Política y Humanidades     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 9)
Chemical Thermodynamics and Thermal Analysis     Open Access   (Followers: 7)
Condensed Matter Physics     Open Access   (Followers: 2)
Diffusion Foundations     Full-text available via subscription   (Followers: 4)
European Journal of Mechanics - B/Fluids     Hybrid Journal   (Followers: 5)
Experimental Heat Transfer     Hybrid Journal   (Followers: 17)
Experimental Thermal and Fluid Science     Hybrid Journal   (Followers: 34)
Fluids     Open Access   (Followers: 1)
Heat and Mass Transfer     Hybrid Journal   (Followers: 28)
Heat Transfer Engineering     Hybrid Journal   (Followers: 37)
High Temperature     Hybrid Journal   (Followers: 2)
HTM Journal of Heat Treatment and Materials     Full-text available via subscription   (Followers: 3)
International Journal of Thermodynamics     Open Access   (Followers: 11)
International Journal of Thermophysics     Hybrid Journal   (Followers: 7)
Journal of Thermodynamics & Catalysis     Open Access   (Followers: 6)
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Journal of Low Temperature Physics     Hybrid Journal   (Followers: 8)
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Journal of Thermodynamics     Open Access   (Followers: 7)
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Low Temperature Physics     Hybrid Journal   (Followers: 6)
Metal Science and Heat Treatment     Hybrid Journal   (Followers: 36)
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