Journal Description
Thermo
Thermo
is an international, peer-reviewed, open access journal on all aspects of thermal sciences, including key features on thermodynamics, statistical mechanics, kinetic theory and satellite areas, published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within ESCI (Web of Science), Scopus, EBSCO, and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 22.8 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2024).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
- Thermo is a companion journal of Entropy.
Latest Articles
Pulsed Laser Deposition Method Used to Grow SiC Nanostructure on Porous Silicon Substrate: Synthesis and Optical Investigation for UV-Vis Photodetector Fabrication
Thermo 2025, 5(2), 13; https://doi.org/10.3390/thermo5020013 - 11 Apr 2025
Abstract
►
Show Figures
In this study, a thin film of silicon carbide (SiC) was deposited on a porous silicon (P-Si) substrate using pulsed laser deposition (PLD). The photo–electrochemical etching method with an Nd: YAG laser at 1064 nm wavelength and 900 mJ pulse energy and at
[...] Read more.
In this study, a thin film of silicon carbide (SiC) was deposited on a porous silicon (P-Si) substrate using pulsed laser deposition (PLD). The photo–electrochemical etching method with an Nd: YAG laser at 1064 nm wavelength and 900 mJ pulse energy and at a vacuum of 10−2 mbar P-Si was utilized to create a sufficiently high amount of surface area for SiC film deposition to achieve efficient SiC film growth on the P-Si substrate. X-ray diffraction (XRD) analysis was performed on the crystalline structure of SiC and showed high-intensity peaks at the (111) and (220) planes, indicating that the substrate–film interaction is substantial. Surface roughness particle topography was examined via atomic force microscopy (AFM), and a mean diameter equal to 72.83 nm was found. Field emission scanning electron microscopy (FESEM) was used to analyze surface morphology, and the pictures show spherical nanoparticles and a mud-sponge-like shape demonstrating significant nanoscale features. Photoluminescence and UV-Vis spectroscopy were utilized to investigate the optical properties, and two emission peaks were observed for the SiC and P-Si substrates, at 590 nm and 780 nm. The SiC/P-Si heterojunction photodetector exhibited rectification behavior in its dark I–V characteristics, indicating high junction quality. The spectral responsivity of the SiC/P-Si observed a peak responsivity of 0.0096 A/W at 365 nm with detectivity of 24.5 A/W Jones, and external quantum efficiency reached 340%. The response time indicates a rise time of 0.48 s and a fall time of 0.26 s. Repeatability was assured by the tight clustering of the data points, indicating the good reproducibility and stability of the SiC/P-Si deposition process. Linearity at low light levels verifies efficient photocarrier generation and separation, whereas a reverse saturation current at high intensities points to the maximum carrier generation capability of the device. Moreover, Raman spectroscopy and energy dispersive spectroscopy (EDS) analysis confirmed the structural quality and elemental composition of the SiC/P-Si film, further attesting to the uniformity and quality of the material produced. This hybrid material’s improved optoelectronic properties, achieved by combining the stability of SiC with the quantum confinement effects of P-Si, make it useful in advanced optoelectronic applications such as UV-Vis photodetectors.
Full article
Open AccessEditorial
Reflecting on the Progress and Future of Thermo
by
Johan Jacquemin
Thermo 2025, 5(1), 12; https://doi.org/10.3390/thermo5010012 - 20 Mar 2025
Abstract
As we embark on a new chapter in 2025, it is with immense pride and gratitude that we reflect on the remarkable journey of Thermo (ISSN 2673-7264; [...]
Full article
Open AccessFeature PaperArticle
Thermochemical Characterization of Sulfur-Containing Furan Derivatives: Experimental and Theoretical Study
by
Luísa M. P. F. Amaral and Manuel A. V. Ribeiro da Silva
Thermo 2025, 5(1), 11; https://doi.org/10.3390/thermo5010011 - 18 Mar 2025
Abstract
The thermochemical properties of three sulfur-containing furan derivatives, 2-furanmethanethiol, furfuryl methyl sulfide, and methyl 2-methyl-3-furyl disulfide, were investigated using experimental and theoretical methods. Standard molar enthalpies of combustion were determined by combustion calorimetry, while enthalpies of vaporization were obtained through Calvet microcalorimetry. These
[...] Read more.
The thermochemical properties of three sulfur-containing furan derivatives, 2-furanmethanethiol, furfuryl methyl sulfide, and methyl 2-methyl-3-furyl disulfide, were investigated using experimental and theoretical methods. Standard molar enthalpies of combustion were determined by combustion calorimetry, while enthalpies of vaporization were obtained through Calvet microcalorimetry. These experimental results allowed for the calculation of standard molar enthalpies of formation in the gas phase at 298.15 K. Theoretical calculations using high-level quantum chemical methods (G3) were performed to complement the experimental data. A comparison between experimental and theoretical values revealed good agreement, validating the computational approach. This study enhances the understanding of the energetic properties of sulfur furan derivatives, contributing reliable thermochemical data to existing databases and aiding in the development of predictive models for related molecular systems.
Full article
(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Molecular Simulation and Thermodynamics)
►▼
Show Figures

Figure 1
Open AccessArticle
Assessing the Feasibility of Integrating a Thermal Separational Method with PV Recycling Technologies
by
Gergely Balázs Patthy, Zsófia Závodi-Fodor and Miklós Jakab
Thermo 2025, 5(1), 10; https://doi.org/10.3390/thermo5010010 - 14 Mar 2025
Abstract
►▼
Show Figures
The growing volume of end-of-life photovoltaic (PV) panels, projected to reach 60–78 million tons by 2050, poses significant environmental challenges. With landfilling being the most cost-effective but unsustainable disposal method, developing eco-friendly processes to recover valuable materials is essential. One potential solution for
[...] Read more.
The growing volume of end-of-life photovoltaic (PV) panels, projected to reach 60–78 million tons by 2050, poses significant environmental challenges. With landfilling being the most cost-effective but unsustainable disposal method, developing eco-friendly processes to recover valuable materials is essential. One potential solution for recovering raw materials from PV panels is thermal treatment. Therefore, in this study, PV modules were heat-treated at a low heating rate, and their components were manually separated with an average efficiency of 90%. The recovered silicon wafers and tempered glass sheets were utilized to fabricate new PV panels using lamination technology. The applied heating parameters enabled the cells to be removed from the PV panels without structural damage. However, the results of electroluminescence tests showed that thermal treatment significantly damages the p-n junctions, rendering direct reuse in new panels unfeasible. The thermal separation methods outlined in this study offer valuable opportunities for industries employing various PV-panel-recycling technologies. These methods lay the groundwork for environmentally responsible management and recovery of materials from end-of-life solar panels, advancing sustainable recycling practices.
Full article

Figure 1
Open AccessFeature PaperArticle
A Novel Capacitive Model of Radiators for Building Dynamic Simulations
by
Francesco Calise, Francesco Liberato Cappiello, Luca Cimmino, Massimo Dentice d’Accadia and Maria Vicidomini
Thermo 2025, 5(1), 9; https://doi.org/10.3390/thermo5010009 - 11 Mar 2025
Abstract
This study addresses the critical challenge of performing a detailed calculation of energy savings in buildings by implementing suitable actions aiming at reducing greenhouse gas emissions. Given the high energy consumption of buildings’ space heating systems, optimizing their performance is crucial for reducing
[...] Read more.
This study addresses the critical challenge of performing a detailed calculation of energy savings in buildings by implementing suitable actions aiming at reducing greenhouse gas emissions. Given the high energy consumption of buildings’ space heating systems, optimizing their performance is crucial for reducing their overall primary energy demand. Unfortunately, the calculations of such savings are often based on extremely simplified methods, neglecting the dynamics of the emitters installed inside the buildings. These approximations may lead to relevant errors in the estimation of the possible energy savings. In this framework, the present study presents a novel 0-dimensional capacitive model of a radiator, the most common emitter used in residential buildings. The final scope of this paper is to integrate such a novel model within the TRNSYS 18simulation environment, performing a 1-year simulation of the overall building-space heating system. The radiator model is developed in MATLAB 2024b and it carefully considers the impact of surface area, inlet temperature, and flow rate on the radiator performance. Moreover, the dynamic heat transfer rate of the capacitive radiator is compared with the one returned by the built-in non-capacitive model available in TRNSYS, showing that neglecting the capacitive effect of radiators leads to an incorrect estimation of the heating consumption. During the winter season, with a heating system turned on from 8 a.m. to 4 p.m. and from 6 p.m. to 8 p.m., the thermal energy is underestimated by roughly 20% with the commonly used non-capacitive model.
Full article
(This article belongs to the Special Issue Innovative Technologies to Optimize Building Energy Performance)
►▼
Show Figures

Figure 1
Open AccessArticle
Power and Energy Requirements for Carbon Capture and Sequestration
by
Efstathios E. Michaelides
Thermo 2025, 5(1), 8; https://doi.org/10.3390/thermo5010008 - 2 Mar 2025
Abstract
►▼
Show Figures
Carbon capture and sequestration have been recently presented as a viable option to reduce atmospheric carbon dioxide emissions and mitigate global climate change. The concept entails the capture, compression, transportation, and injection of the gas into a medium suitable for storage. This paper
[...] Read more.
Carbon capture and sequestration have been recently presented as a viable option to reduce atmospheric carbon dioxide emissions and mitigate global climate change. The concept entails the capture, compression, transportation, and injection of the gas into a medium suitable for storage. This paper examines the thermodynamic and transport properties of carbon dioxide that are pertinent to its sequestration and storage, describes the various methods that have been recommended for its separation from the mixture of the flue gases, and determines the mechanical power and heat rate required for the capture of the gas. The power required for the compression and transportation of the gas by a pipeline is also determined, as well as the effect of the ambient temperature on the transportation power. Calculations for the total power required are performed for two cases, one a cement production unit and the second a coal power plant. The mechanical power needed for the sequestration of CO2 is substantial in both cases, with the cement unit needing less power because of the availability of high-temperature waste heat. In both cases, the equivalent mechanical work needed for the sequestration and storage of this gas is on the order of 1 MJ per kg CO2 sequestered.
Full article

Figure 1
Open AccessArticle
Nusselt Number Dependence on Friction Factor in the Boundary Slip Flow of a Newtonian Liquid Between Parallel Plates
by
Krishna Kota, Sarada Kuravi and Prasanna Jayaramu
Thermo 2025, 5(1), 7; https://doi.org/10.3390/thermo5010007 - 17 Feb 2025
Abstract
►▼
Show Figures
This study explored the relationship between the Nusselt number and the friction factor in the laminar boundary slip flow of a Newtonian liquid between parallel plates. In addition, simplified equations were developed to estimate two key parameters—slip velocity and temperature jump—both of which
[...] Read more.
This study explored the relationship between the Nusselt number and the friction factor in the laminar boundary slip flow of a Newtonian liquid between parallel plates. In addition, simplified equations were developed to estimate two key parameters—slip velocity and temperature jump—both of which are typically difficult to measure in experimental settings. The primary objectives of investigating the relationship between the Nusselt number and the friction factor were twofold: (1) to uncover the previously unknown mathematical connection (or analogy) between momentum transfer and heat transfer in the presence of boundary slip and (2) to enable predictions of either the pressure drop or the heat transfer coefficient by measuring just one of these quantities, thus simplifying experimental procedures. Considering the difficulty of conducting experiments of this type of flow (as described in the published literature), a finite element-based numerical model built in COMSOL Multiphysics software was used to validate the theoretically developed relationship over a wide range of Reynolds numbers and boundary slip values. While surface modifications like dimples, bumps, and ribs typically modify both the Nusselt number and pressure drop, leading to their increase for a given fluid and constant inlet Reynolds number, their behavior changes when boundary slip is present, particularly in cases where there is a low temperature jump at the wall. The analysis identified a specific threshold for the dimensionless temperature jump below which the Nusselt number with boundary slip will exceed 8.235. Furthermore, the analysis showed that for the Nusselt number to rise above 8.235, the non-dimensional velocity slip must be at least 3.19 times larger than the non-dimensional temperature jump. This means that the velocity slip has to be significantly larger than the temperature jump to achieve enhanced heat transfer in boundary slip flows.
Full article

Figure 1
Open AccessArticle
Design and Implementation of Multi-Channel Temperature Measurement System of Thermal Test Chip Based on Diode Temperature-Sensitive Arrays
by
Lina Ju, Peng Jiang, Xing Zhou, Ruiwen Liu, Yanmei Kong, Yuxin Ye, Binbin Jiao, Honglin Sun and Fan Wei
Thermo 2025, 5(1), 6; https://doi.org/10.3390/thermo5010006 - 12 Feb 2025
Abstract
►▼
Show Figures
When chips perform numerous computational tasks or process complex instructions, they generate substantial heat, potentially affecting their long-term reliability and performance. Thus, accurate and effective temperature measurement and management are crucial to ensuring chip performance and lifespan. This paper presents a multi-channel temperature
[...] Read more.
When chips perform numerous computational tasks or process complex instructions, they generate substantial heat, potentially affecting their long-term reliability and performance. Thus, accurate and effective temperature measurement and management are crucial to ensuring chip performance and lifespan. This paper presents a multi-channel temperature measurement system based on a diode temperature-sensitive array thermal test chip (TTC). The thermal test chip accurately emulates the heat power and thermal distribution of the target chip, providing signal output through row and column address selection. The multi-channel temperature measurement system centers around a microcontroller and includes voltage signal acquisition circuits and host computer software. It enables temperature acquisition, storage, and real-time monitoring of 16 channels in a 4 × 4 array thermal test chip. During experiments, the system uses a constant current source to drive temperature-sensitive diodes, collects diode output voltage through multiplexers and high-precision amplification circuits, and converts analog signals to digital signals via a high-speed ADC. Data transmission occurs via the USB 2.0 protocol, with the host computer software handling data processing and real-time display. The test results indicate that the system accurately monitors chip temperature changes in both steady-state and transient thermal response tests, closely matching measurements from a semiconductor device analyzer, with an error of about 0.67%. Therefore, this multi-channel temperature measurement system demonstrates excellent accuracy and real-time monitoring capability, providing an effective solution for the thermal design and evaluation of high power density integrated circuits.
Full article

Figure 1
Open AccessArticle
Thermodynamic Model of a Gas Turbine Considering Atmospheric Conditions and Position of the IGVs
by
Tarik Boushaki and Kacem Mansouri
Thermo 2025, 5(1), 5; https://doi.org/10.3390/thermo5010005 - 7 Feb 2025
Abstract
►▼
Show Figures
Gas turbines are widely used in power generation due to their efficiency, flexibility, and low environmental impact. Modeling, especially in thermodynamics, is crucial for the designer and operator of a gas turbine. An advanced and rigorous thermodynamic model is essential to accurately predict
[...] Read more.
Gas turbines are widely used in power generation due to their efficiency, flexibility, and low environmental impact. Modeling, especially in thermodynamics, is crucial for the designer and operator of a gas turbine. An advanced and rigorous thermodynamic model is essential to accurately predict the performance of a gas turbine under on-design operating conditions, off-design or failure. Such models not only improve understanding of internal processes but also optimize performance and reliability in a wide variety of operational scenarios. This article presents the development of a thermodynamic model simulating the off-design performance of a gas turbine. The mathematical relationships established in this model allow for quick calculations while requiring a limited amount of data. Only nominal data are required, and some additional data are needed to calibrate the model on the turbine under study. A key feature of this model is the development of an innovative relationship that allows direct calculation of the mass flow of air entering the turbine and, thus, the performances of the turbine according to atmospheric conditions (such as pressure, temperature, and relative humidity) and the position of the compressor inlet guide vanes (IGV). The results of the simulations, obtained using code implemented in MATLAB (R2014a), demonstrate the efficiency of the model compared to experimental data. Indeed, the model relationships exhibit high determination coefficients (R2 > 0.95) and low root mean square errors (RMSE). Specifically, the simulation results for the air mass flow rate demonstrate a very high determination coefficient (R2 = 0.9796) and a low root mean square error (RMSE = 0.0213).
Full article

Figure 1
Open AccessArticle
Numerical Analysis of Transient Burn Injury Grading Through Coupled Heat Transfer and Damage Integral Modeling
by
Chao Zhang, Xinbin Ma, Mengxi Li, Yubin Qiu, Moon Keun Kim and Jiying Liu
Thermo 2025, 5(1), 4; https://doi.org/10.3390/thermo5010004 - 4 Feb 2025
Abstract
►▼
Show Figures
The accurate assessment of parameters such as burn degree, volume, and depth is a prerequisite for the effective treatment of patients. However, as an unsteady heat transfer process, the temperature of the burn damage volume changes over time, and it is difficult to
[...] Read more.
The accurate assessment of parameters such as burn degree, volume, and depth is a prerequisite for the effective treatment of patients. However, as an unsteady heat transfer process, the temperature of the burn damage volume changes over time, and it is difficult to accurately calculate the integral value of the damage, which is used to assess the burn degree. Therefore, it is impossible to accurately determine the location and volume of damage at all burn degrees. In this study, the C language is used to program a user-defined function of the burn damage integral formula, and the coupled numerical simulation method is used to calculate the heat transfer and damage in a high-temperature water burn process. Then, the temperature and burn damage integral value of each point can be determined to accurately assess and distinguish the burn degree in real time, and estimate the position distribution, volume size, and transient change trend of each burn degree. Under the working conditions selected in this paper, the heat source mainly affects the epidermis and dermis directly below, and has less influence on the area above, which is in convective heat transfer. The damage integral value is very sensitive to temperature, and the highest damage integral value caused by 373 K is two and four orders of magnitude higher than that of 363 K and 353 K, respectively. The increase in the heat source temperature caused the volume of a third-degree burn to increase rapidly in the early stage of injury, but the volume of second-degree and first-degree burns did not change much. After heating at 373 K for 15 s and delaying the action for 45 s, the volume of first-, second-, and third-degree burns accounted for 0.4, 2.9, and 1.9%, respectively, and the total volume of damage accounted for only 5.2% of the total volume.
Full article

Figure 1
Open AccessArticle
Energy and Exergy Analyses Applied to a Crop Plant System
by
Heba Alzaben and Roydon Fraser
Thermo 2025, 5(1), 3; https://doi.org/10.3390/thermo5010003 - 30 Jan 2025
Abstract
►▼
Show Figures
The second law of thermodynamics investigates the quality of energy, or in other words exergy, described as the maximum useful to the dead-state work. The objective of this paper is to investigate the energy and exergy flows in a crop plant system in
[...] Read more.
The second law of thermodynamics investigates the quality of energy, or in other words exergy, described as the maximum useful to the dead-state work. The objective of this paper is to investigate the energy and exergy flows in a crop plant system in order to identify the dominant flows and parameters (e.g., temperature) affecting crop plant development. The need for energy and exergy analyses arises from the hypothesis that crop stress can be detected via surface temperature measurements, as explained by the exergy destruction principle (EDP). Based on the proposed energy model, it is observed that radiation and transpiration terms govern all other terms. In addition, as a result of exergy analysis, it is observed that solar exergy governs all input and output terms. The results obtained from this study support the hypothesis that crop surface temperature can be utilized as an indicator to detect crop stress.
Full article

Figure 1
Open AccessCorrection
Correction: Rabi’ et al. Packed Bed Thermal Energy Storage System: Parametric Study. Thermo 2024, 4, 295–314
by
Ayah Marwan Rabi’, Jovana Radulovic and James M. Buick
Thermo 2025, 5(1), 2; https://doi.org/10.3390/thermo5010002 - 17 Jan 2025
Abstract
►▼
Show Figures
In the original publication [...]
Full article

Figure 1
Open AccessArticle
Optimal Design Parameters for Supercritical Steam Power Plants
by
Victor-Eduard Cenușă and Ioana Opriș
Thermo 2025, 5(1), 1; https://doi.org/10.3390/thermo5010001 - 16 Jan 2025
Abstract
Steam thermal power plants represent important energy production systems. Within the energy mix, these could allow flexible generation and the use of hybrid systems by integrating renewables. The optimum design solution and parameters allow higher energy efficiency and lower environmental impact. This paper
[...] Read more.
Steam thermal power plants represent important energy production systems. Within the energy mix, these could allow flexible generation and the use of hybrid systems by integrating renewables. The optimum design solution and parameters allow higher energy efficiency and lower environmental impact. This paper analyzes single reheat supercritical steam power plants design solutions using a genetic heuristic algorithm. A multi-objective optimization was made to find the Pareto frontier that allows the maximization of the thermal cycle net efficiency and minimization of the specific investment in the power plant equipment. The Pareto population was split and analyzed depending on the total number of preheaters. The mean values and the standard deviations were found for the objective functions and main parameters. For the thermal cycle schemes with eight preheaters, the average optimal thermal cycle efficiency is (48.09 ± 0.16)%. Adding a preheater increases the average optimal thermal cycle efficiency by 0.64%, but also increases the average optimum specific investments by 7%. It emphasized the importance of choosing a proper ratio between the reheating and the main steam pressure. Schemes with eight and nine preheaters have an average optimum value of 0.178 ± 0.021 and 0.220 ± 0.011, respectively. The results comply with data from the literature.
Full article
(This article belongs to the Special Issue Innovative Technologies to Optimize Building Energy Performance)
►▼
Show Figures

Figure 1
Open AccessFeature PaperArticle
The Viscosity of Liquids in the Dual Model
by
Fabio Peluso
Thermo 2024, 4(4), 508-539; https://doi.org/10.3390/thermo4040028 - 3 Dec 2024
Abstract
►▼
Show Figures
In this paper, a reliable model of the viscosity in liquids in the dual model of liquids (DML) framework is developed. The analytical expression arrived at exhibits the correct T–dependence Arrhenius-like exponential decreasing trend, which is typical of Newtonian simple fluids. The
[...] Read more.
In this paper, a reliable model of the viscosity in liquids in the dual model of liquids (DML) framework is developed. The analytical expression arrived at exhibits the correct T–dependence Arrhenius-like exponential decreasing trend, which is typical of Newtonian simple fluids. The model is supported by the successful comparison with both the experimental values of the viscosity of water, and with those related to the mechano-thermal effect in liquids under low-frequency shear, discovered a few years ago, for which the first-ever theoretical interpretation is given by the DML. Moreover, the approach is even supported by the results of numerical models recently developed, that have shown that dual liquid models, such as the DML, provides very good agreement with experimental data. The expression of viscosity contains terms belonging to both the subsystems constituting the liquid, and shows an explicit dependence upon the sound velocity and the collective vibratory degrees of freedom (DoF) excited at a given temperature. At the same time, the terms involved depend upon the Boltzmann and Planck constants. Finally, the physical model is coherent with the Onsager postulate of microscopic time reversibility as well as with time’s arrow for macroscopic dissipative mechanisms.
Full article

Figure 1
Open AccessFeature PaperArticle
Study of the Pyrolysis of Ayous and Kambala Co-Products: Kinetic Modeling of the Two Species
by
Mamoun Clévie Aboni Akodzi, Pierre Girods, Timoléon Andzi-Barhé and Yann Rogaume
Thermo 2024, 4(4), 490-507; https://doi.org/10.3390/thermo4040027 - 12 Nov 2024
Abstract
A kinetic model based on the two-stage semi-global multi-reaction model of Grioui was developed using the TG and DTG curves for the by-products of Kambala and Ayous. These two tropical species are widely used in the Republic of Congo. The TG and DTG
[...] Read more.
A kinetic model based on the two-stage semi-global multi-reaction model of Grioui was developed using the TG and DTG curves for the by-products of Kambala and Ayous. These two tropical species are widely used in the Republic of Congo. The TG and DTG curves were obtained through thermogravimetry at five different heating rates (3, 7, 10, and 20 K/min) up to a final temperature of 800 °C under a nitrogen atmosphere. The thermal decomposition of both species started at similar temperatures, but the profiles exhibited notable differences. Kambala showed a distinct profile with two peaks at approximately 500 °C and 700 °C, which upon further investigation were found to correspond to ash decomposition. Additionally, the shoulder present in Ayous between 250 °C and 300 °C, attributed to hemicelluloses degradation, was absent in the DTG curves for Kambala. The kinetic model for Ayous was formulated in three steps, while the model for Kambala consisted of four steps. Both models accurately predicted the thermal degradation of the wood species, and the resulting kinetic parameters aligned with those reported in the literature.
Full article
(This article belongs to the Special Issue Thermal Processes and Thermal Properties of Sustainable Polymeric Materials)
►▼
Show Figures

Figure 1
Open AccessArticle
Heat Exchanger Improvement of a Counter-Flow Dew Point Evaporative Cooler Through COMSOL Simulations
by
Mario García-González, Guanggui Cheng, Duc Thuan Bui and Josué Aarón López-Leyva
Thermo 2024, 4(4), 475-489; https://doi.org/10.3390/thermo4040026 - 12 Nov 2024
Abstract
Due to modern comfort demands and global warming, heating, ventilation, and air conditioning (HVAC) systems are widely used in many homes and buildings. However, HVAC based on the Vapor Compression System (VCS) is a major energy consumer, accounting for 20–50% of a building’s
[...] Read more.
Due to modern comfort demands and global warming, heating, ventilation, and air conditioning (HVAC) systems are widely used in many homes and buildings. However, HVAC based on the Vapor Compression System (VCS) is a major energy consumer, accounting for 20–50% of a building’s energy consumption and responsible for 29% of the world’s CO2 emissions. Dew-point evaporative coolers offer a sustainable alternative yet face challenges, e.g., dew point and wet bulb effectiveness. Given the above, dew point evaporative cooling systems may find a place to dethrone conventional air conditioning systems. This research aims to design a dew point evaporative cooler system with better performance in terms of dew point and wet bulb effectiveness. In terms of methodology, a heat exchanger as part of a counter-flow dew point cooling system was designed and analyzed using COMSOL simulations under different representative climatic, geometric, and dimensional conditions, taking into account turbulent flow. Next, our model was compared with other cooling systems. The results show that our model performs similarly to other cooling systems, with an error of around 6.89% in the output temperature at low relative humidity (0–21%). In comparison, our system is more sensitive to humidity in the climate, whereas heat pumps can operate in high humidity. The average dew point and wet bulb effectiveness were also higher than reported in the literature, at 91.38% and 147.84%, respectively. In addition, there are some potential limitations of the simulations in terms of the assumptions made about atmospheric conditions. For this reason, the results cannot be generalized but must be considered as a starting point for future research and technology development projects.
Full article
(This article belongs to the Special Issue Innovative Technologies to Optimize Building Energy Performance)
►▼
Show Figures

Figure 1
Open AccessArticle
Laboratory Experiments on Passive Thermal Control of Space Habitats Using Phase-Change Materials
by
Claudia Ongil, Úrsula Martínez, Pablo Salgado Sánchez, Andriy Borshchak Kachalov, Jose Miguel Ezquerro and Karl Olfe
Thermo 2024, 4(4), 461-474; https://doi.org/10.3390/thermo4040025 - 29 Oct 2024
Cited by 1
Abstract
Here, we investigate the performance of phase-change materials (PCMs) in the passive thermal control of space habitats. PCMs are able to absorb and release large amounts energy in the form of latent heat during their (typically, solid-to-liquid) phase transition, which makes them an
[...] Read more.
Here, we investigate the performance of phase-change materials (PCMs) in the passive thermal control of space habitats. PCMs are able to absorb and release large amounts energy in the form of latent heat during their (typically, solid-to-liquid) phase transition, which makes them an ideal choice for passive temperature control. In this study, a conceptual design of an igloo-shaped habitat is proposed. A scaled model for laboratory experiments is manufactured via 3D printing, using tap water as the PCM. The setup is used to conduct experiments and analyze PCM performance, based on temperature measurements inside and outside the habitat. Results demonstrate the effectiveness of PCMs in increasing thermal inertia and stabilizing the habitat interior temperature around the melting temperature, confirming that PCMs can be a suitable alternative for passive thermal control. The present study holds significant interest for the future of space exploration, with the emerging need to design habitats that are capable of accommodating astronauts.
Full article
(This article belongs to the Special Issue Advances in PCMs as Thermal Energy Storage in Energy Systems)
►▼
Show Figures

Figure 1
Open AccessFeature PaperArticle
Mixed Thermal and Renewable Energy Generation Optimization in Non-Interconnected Regions via Boolean Mapping
by
Pavlos Nikolaidis
Thermo 2024, 4(4), 445-460; https://doi.org/10.3390/thermo4040024 - 23 Oct 2024
Cited by 1
Abstract
►▼
Show Figures
Global efforts aiming to shift towards renewable energy and smart grid configurations require accurate unit commitment schedules to guarantee power balance and ensure feasible operation under different complex constraints. Intelligent systems utilizing hybrid and high-level techniques have arisen as promising solutions to provide
[...] Read more.
Global efforts aiming to shift towards renewable energy and smart grid configurations require accurate unit commitment schedules to guarantee power balance and ensure feasible operation under different complex constraints. Intelligent systems utilizing hybrid and high-level techniques have arisen as promising solutions to provide optimum exploration–exploitation trade-offs at the expense of computational complexity. To ameliorate this requirement, which is extremely expensive in non-interconnected renewable systems, radically different approaches based on enhanced priority schemes and Boolean encoding/decoding have to take place. This compilation encompasses various mappings that convert multi-valued clausal forms into Boolean expressions with equivalent satisfiability. Avoiding any need to introduce prior parameter settings, the solution utilizes state-of-the-art advancements in the field of artificial intelligence models, namely Boolean mapping. It allows for the efficient identification of the optimal configuration of a non-convex system with binary and discontinuous dynamics in the fewest possible trials, providing impressive performance. In this way, Boolean mapping becomes capable of providing global optimum solutions to unit commitment utilizing fully tractable procedures without deteriorating the computational time. The results, considering a non-interconnected power system, show that the proposed model based on artificial intelligence presents advantageous performance in terms of generating cost and complexity. This is particularly important in isolated networks, where even a-not-so great deviation between production and consumption may reflect as a major disturbance in terms of frequency and voltage.
Full article

Figure 1
Open AccessFeature PaperArticle
Closed-Form Solutions for Current Distribution in Ladder-Type Textile Heaters
by
Kaspar M. B. Jansen
Thermo 2024, 4(4), 433-444; https://doi.org/10.3390/thermo4040023 - 26 Sep 2024
Abstract
►▼
Show Figures
Textile heaters are made from knitted conductive yarns integrated into their fabric, making them stretchable, washable, breathable and suitable for close-to-skin wear. However, the non-zero resistance in the lead wires causes non-uniform power distribution, which presents a design challenge. To address this, the
[...] Read more.
Textile heaters are made from knitted conductive yarns integrated into their fabric, making them stretchable, washable, breathable and suitable for close-to-skin wear. However, the non-zero resistance in the lead wires causes non-uniform power distribution, which presents a design challenge. To address this, the electrical performance of the heaters is modeled as an n-ladder resistor network. By using the finite difference method, simple, closed-form expressions are derived for networks with their power source connected to input terminals A1B1 and A1Bn, respectively. The exact results are then used to derive approximations and design criteria. The solutions for the ladder networks presented in this paper apply to a wider class of physical problems, such as irrigation systems, transformer windings, and cooling fins.
Full article

Figure 1
Open AccessFeature PaperReview
Linking Solution Microstructure and Solvation Thermodynamics of Mixed-Solvent Systems: Formal Results, Critical Observations, and Modeling Pitfalls
by
Ariel A. Chialvo
Thermo 2024, 4(3), 407-432; https://doi.org/10.3390/thermo4030022 - 22 Sep 2024
Abstract
This review provides a critical assessment of the current state of affairs regarding the solvation thermodynamics involving mixed-solvent systems. It focuses specifically on (i) its rigorous molecular-based foundations, (ii) the underlying connections between the microstructural behavior of the mixed-solvent
[...] Read more.
This review provides a critical assessment of the current state of affairs regarding the solvation thermodynamics involving mixed-solvent systems. It focuses specifically on (i) its rigorous molecular-based foundations, (ii) the underlying connections between the microstructural behavior of the mixed-solvent environment and its thermodynamic responses, (iii) the microstructural characterization of the behavior of the mixed-solvent environment around the dilute solute via unique fundamental structure-making/-breaking functions and the universal preferential solvation function, (iv) the discussion of potential drawbacks associated with the molecular simulation-based determination of thermodynamic preferential interaction parameters, and (v) the forensic examination of frequent modeling pitfalls behind the interpretation of preferential solvation from experimental data of Gibbs free energy of solute transfer.
Full article
(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Molecular Simulation and Thermodynamics)
►▼
Show Figures

Figure 1
Highly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Applied Sciences, Clean Technol., Energies, Sustainability, Thermo
Clean Energy Technologies and Assessment, 2nd Edition
Topic Editors: Francesco Calise, Maria Vicidomini, Rafał Figaj, Francesco Liberato CappielloDeadline: 31 December 2026

Conferences
Special Issues
Special Issue in
Thermo
Editorial Board Members’ Collection Series: Molecular Simulation and Thermodynamics
Guest Editors: Santiago Aparicio, Johan Jacquemin, Steve Lustig, Andrew S. Paluch, William E. Acree, Jr.Deadline: 20 May 2025
Special Issue in
Thermo
Frosting and Icing
Guest Editors: Mengjie Song, Xuan Zhang, Long Zhang, Seyyed Hossein Hosseini, Libor Pekař, Keke ShaoDeadline: 15 June 2025
Special Issue in
Thermo
Thermal Processes and Thermal Properties of Sustainable Polymeric Materials
Guest Editors: George Z. Papageorgiou, Johan JacqueminDeadline: 10 July 2025
Special Issue in
Thermo
Thermal Energy Modeling in Microgrids with Urban Air Mobility
Guest Editors: Zhuoli Zhao, Yujie Yuan, Chun Sing Lai, Loi Lei LaiDeadline: 31 October 2025