Applied sciences

Archives of Thermodynamics

Content

Archives of Thermodynamics | 2025 | vol. 46 | No 1

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Abstract

Liquid Crystals Thermography, Particle Image Velocimetry, Infrared Imaging Thermography and Digital Infrared Imaging have been successfully used in non-intrusive technical, industrial and biomedical studies and applications. These four tools (based on the desktop computers) have come together during the past two decades to produce a powerful advanced experimental technique as a judgment of quality of information that cannot be obtained from any other imaging procedure. A brief summary of the history of this technique is reviewed, principal methods and tools are described and some examples are presented mostly from our own research. Automated data evaluation allows us to determine the heat and flow visualization and locate the area of suspicious tissue in the human body. Anyway with this objective, a relatively new experimental technique has been developed and applied to the study of heat and mass transfer and for biomedical diagnosis.
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Authors and Affiliations

Jan A. Stąsiek
1
Michał E. Klugmann
1
Dariusz P. Mikielewicz
1

  1. Gdańsk University of Technology, Faculty of Mechanical Engineering and Ship Technology, ul. Narutowicza 11/12, 80-233 Gdańsk, Poland
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Abstract

This paper is dedicated to the multi-aspect optimization of a novel thermo-hydraulic machine with liquid piston operating according to organic Rankine cycle, designed for mechanical power generation from low temperature reservoirs. This involves the implementation of thermodynamic and hydraulic analyses. Several issues have been identified in thermo-hydraulic machines built to date, particularly the limitation imposed by the location of the expansion phase under the equilibrium dome, which constrains maximum output work. This issue is addressed through the application of steam su-perheating followed by the organic Rankine cycle. The thermodynamic analysis showed that the R1233zd is the most suitable working fluid for the suggested novel machine within the temperature range of 65−130°C. The selection of the best working fluid was followed by the dimensioning of the hydraulic part of the machine under optimal operating condi-tions. A new parameter was introduced to link the gas and hydraulic sides of the machine. It is about the time scale of the cycle which influences significantly the mechanical output power. Furthermore, mathematical modelling of the hydraulic part of the machine concludes that high mechanical power output can only be achieved only in modes of operation with high thermal efficiencies. Conversely, operational modes with high second law efficiencies fail to deliver high mechanical power levels. These two conclusions can be regarded as equivalent to the various postulates of the second law of thermo-dynamics.
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Authors and Affiliations

Asmaa Guelib
1
Djallel Zebbar
2
Zakaria Rahmani
2
Souhila Zebbar
2
Kouider Mostefa
2
Sahraoui Kherris
2
ORCID: ORCID
Said Mekroussi
1

  1. Research Laboratory of Industrial Technologies, Departmentof Mechanical Engineering, Faculty of Applied Sciences, Ibn Khaldoun University, B.P. 78 Zaâroura 14000 Tiaret, Algeria
  2. Laboratory of Mechanical Engineering, Materials and Structures, Faculty of Sciences and Technology, Tissemsilt University  Ahmed ben Yahia Elwancharissi, Benhamouda B.P 182, 38010 Tissemsilt, Algeria
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Abstract

Vapour-liquid equilibrium calculation is crucial in oil industry and multi-phase systems such as droplet evaporation. This paper presents a comprehensive numerical analysis of phase equilibrium in multi-component systems at various pressures and temperatures, accounting for high-pressure phenomena including thermodynamic non-ideality and inert gas effects. The phase equilibrium is determined by solving the fugacity equation iteratively to find the equilibrium mole fractions in both liquid and vapour phases. The Peng-Robinson equation of state is used to handle non-idealities and calculate fugacity coefficients. This study details the procedure for computing vapour-liquid equilibrium and evaluates N2, O2, and CO2 solubility in liquid alkanes such as heptane, dodecane, and hexadecane. Model performance is validated against experi-mental data for binary and ternary systems, showing good agreement. Results indicate that density and molecular attractive forces impact gas dissolution. Increased pressure and gas density enhance solubility in the liquid phase, while temperature effects vary between subcritical and supercritical regions. The study also highlights differences in gas solubility between heavy and light fluids.
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Authors and Affiliations

Mohammad Reza Goodarzi
1
Hojat Ghassemi
1

  1. School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, P.O.B. 16765-163, Iran
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Abstract

Rocket thrusters of various types are used in space to change orbits, maneuver, and position control. The progressive trend in miniaturization of satellites also entails changes in propulsion systems. In recent years, electric rocket thrusters have become increasingly important. Resistojets are one of the simplest types offering thrust ranging from several to hundreds of millinew-tons and use two types of energy: potential (pressure) and electrical. Electrical energy added by a resistive element – a heater – allows a significant increase in the temperature and specific impulse of the working medium. The paper considers the case of damage or lack of electrical power to the heater, which changes the engine operating mode from resistojet to coldgas. Experimental tests were carried out on a model of resistojet thruster operating in atmospheric conditions, both with the heater on and off. For the resistojet mode (heater on), three different variants of the flow delay to the heater activation time were considered. The analysis of results showed how the key propulsion parameters of the thruster change: specific impulse, total impulse, thrust and mass flow rate. For the tested model engine, wherein the resistojet mode the temperature was higher by approximately 120°C compared to coldgas, and approximately a 30% increase in specific impulse was observed. This demon-strates the advantages of the resistojet, where a heater failure ”only” causes a reduction in the propulsion potential and not its complete loss. The spaceship or a satellite with resistojet thruster onboard has still the opportunity to accomplish mission goals.
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Authors and Affiliations

Jan Kindracki
1
Michał Romanowski
1

  1. Institute of Heat Engineering, Faculty of Power and Aeronautical Engineering, Warsaw University of Technology.Nowowiejska 21/25, 00-665 Warsaw, Poland
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Abstract

The leakage of natural gas pipelines will waste energy and damage the environment. Research on the leakage and diffusion features of hydrogen-doped natural gas is beneficial to the safe management of natural gas pipelines. This paper established a numerical model used for simulating and computing the diffusion of hydrogen-doped natural gas. Then, simulation experi-ments were conducted. First, the model accuracy was verified through experiments, and the appropriate mesh number of the model was determined. Then, the influence of different hydrogen blending ratios and various leakage hole diameters on the leakage and diffusion of gas was calculated. Under the same diffusion time, the higher the hydrogen content in the gas, the higher the diffusion rate of methane and hydrogen, and the diffusion rate of hydrogen had the most obvious change. Under the same diffusion time, the closer to the leakage hole, the higher the concentration of natural gas, and the concentration at the monitoring points at the same level differed little.
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Authors and Affiliations

Xiang Zhou
1
Dewen Kong
1
Teng Ren
2

  1. Jiangsu Vocational College of Information Technology, No. 1 Qianou Road, Huishan District, Wuxi City, Jiangsu 214153, China
  2. Shenyang University of Technology, Shenyang, Liaoning 110023, China
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Abstract

In this work, thermomagnetic convection and irreversibility production in a hybrid nanofluid-filled wavy-walled porous thermal system containing a semi-circular heated bottom is presented. Both the sidewalls of the enclosure are cooled and undulated with varying undulation numbers. The lower wall is partially undulated following a semi-circular-shaped object and is heated isothermally. The horizontal walls are insulated. The cavity is occupied with Cu-Al2O3/water-based hybrid nanofluid and porous substances under the impact of the evenly applied horizontal magnetic field. This work significantly contributes to the existing research rendering an exhaustive understanding of the hydrothermal flow-physics as well as irreversibility production of a hybrid nanofluid in the cavity having surface undulation. The Galerkin weighted finite ele-ment method is utilized to solve the mathematical model. The hydrothermal performance of the thermal system is con-siderably influenced by various pertinent factors such as Darcy-Rayleigh number, Darcy number, Hartmann number, and number of undulations. The wall undulations have a critical role in altering the hydrothermal performance. Heatlines are used to analyse heat transport dynamics from the protruded hot surface to the heat sink. The protruded heater wall induces the formation of a hot upward plume in the nearest fluid layers. The flow divides into two parts forming a pair of circula-tions due to symmetrical cooling at the sidewalls. The flow behaviours are significantly dampened by increasing the Hart-mann number. The associated total entropy generation is also demonstrated. This study contributes to the existing domain knowledge and provides insights for designing and optimizing similar thermal systems.
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Authors and Affiliations

Nirmalendu Biswas
1
Dipak Kumar Mandal
2
Nirmal K. Manna
3
Ali Cemal Benim
4

  1. Department of Power Engineering, Jadavpur University, Salt Lake, Kolkata-700106, India
  2. Department of of Mechanical Engineering, Government Engineering College Samastipur, Bihar-848127, India
  3. Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, India
  4. Department Mechanical and Process Engineering, Duesseldorf University of Applied Sciences, Germany
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Abstract

This paper investigates the flow and heat transfer characteristics of CuO–water nanofluid in a square channel with an inner triangular groove that is continuously heated. By applying a transverse magnetic field, the governing coupled and nonlinear equations are solved using the Galerkin finite element method across various Reynolds numbers. The analysis provides com-prehensive insights into the effects of different parameters through stream plots and contour plots. The heat transfer rate, represented by the Nusselt number (Nu), is graphically presented for the heated inner triangular groove and thoroughly dis-cussed. Results indicate that the flow rate significantly influences heat transfer, particularly for high Reynolds numbers, with notable effects observed in both the upper and lower parts of the channel. Optimal heat transfer is achieved at a 3% concen-tration of CuO nano-particles, highlighting the potential for enhanced thermal performance in such configurations.
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Authors and Affiliations

Baradi Lavanya
1 2
Gosukonda Srinivas
3
Baluguri Suresh Babu
4
Oluvole Daniel Makinde
5

  1. Bharatiya Engineering Science & Technology Innovation University, Gorantla, Andhra Pradesh- 515231, India
  2. St. Francis College for Women, Hyderabad,Telangana-500 016, India
  3. Geethanjali college of Engineering and Technology, Hyderabad,Telangana-500 016, India
  4. Sreyas Institute of Engineering and Technology, Hyderabad,Telangana-500 068, India
  5. Stellenbosch University, Private Bag X2, Saldanha 7395, South Africa
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Abstract

Screening for eco-friendly working fluids with high-energy efficiency is one of the highest challenges in the air conditioning sector. The present research aims to investigate and compare the performance characteristics of fourteen promising low global warming potential working fluids, less than 150, in solar organic Rankine cycle powered vapour compression cycle for air conditioning of residential buildings. The working fluids selected are R152a, R161, R1234yf, R1234ze(E), R1233zd(E), R290, R1270, R600a, R600, R601a, R601, R13I1, RE170 and R123. The performance characteristics investigated are the organic Rankine cycle efficiency (ηORC), the ratio (WRm) of network output (Wnet) for the organic Rankine cycle to mass flow (mORC) rate for organic Rankine cycle, volumetric flow ratio (VFR), expander size parameter (SP), cooling power (Qeva) of vapour compression cycle, coefficient of performance (COPVCC) of vapour compression cycle, coefficient of performance (COPs) of the organic Rankine cycle–vapour compression cycle system, the ratio (CPRm) of cooling power (Qeva) to (mORC+mVCC), and the total efficiency of solar air conditioning system (ηt). The investigated results proved that the working fluid RE170 (global warming potential = 1) is the most suitable working fluid for the organic Rankine cycle–vapour compression cycle system through the comprehensive comparison of ηORC, WRm, VFR, SP, Qeva, COPVCC , COPs, CPRm and ηt for the fourteen working fluids.

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Authors and Affiliations

Youcef Maalem
1
Hakim Madani
2

  1. Ecole Nationale Polytechnique de Constantine (ENPC), BP75 A, Nouvelle Ville RP, 25000 Constantine, Alger
  2. LESEI, Department of Mechanical Engineering, Faculty of Technology, University of Batna 2, 05000 Batna, Algeria
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Abstract

This paper discusses 2 examples of using waste heat from a brewery cooling process with heat pumps. The first example is the transfer of condensation heat to the heat usable for bottling, mashing or in the return flow of a district heating system to increase the water temperature. The second is the use of superheating heat to increase the return water temperature of a district heating network or mashing, lautering or bottling. Both possible solutions for the use of heat pumps offer real possibilities of introducing part or all of the waste heat of the cooling system to the level of useful temperatures. The 1st concept (usage of heat of condensation and discharge gas heat) is much more interesting because it gives real savings for the plant and possibilities of selling heat to an external recipient. The temperature level is also sufficient to cover all own technological purposes at temperatures up to 70°C.
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Authors and Affiliations

Stefan Reszewski
1
Tomasz Hałon
1

  1. Wroclaw University of Science and Technology, Departmentof Thermal Sciences, Wyspianskiego 27, 50-370 Wroclaw, Poland
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Abstract

Split cooling devices are widely used in different regions of the world. These devices work in high ambient temperatures during the summer months in many countries, such as Iraq, which increases electrical energy consumption and decreases the coefficient of performance. In addition, high temperatures expose the devices to damage, which means more mainte-nance and costs. This work investigates the potential of using a direct evaporative cooling system integrated with a split air conditioning unit to enhance the cooling performance and provide optimum operational conditions. The use of evapo-rative cooling is to reduce the condenser temperature of the outdoor split unit in the extremely hot summer. The mathe-matical development of the related equation is used to predict the cooling effectiveness. The climate conditions have been selected according to the Karbala city, Iraq, as it has a dry and hot climate, in which the temperatures may exceed 50°C. The results demonstrated the possibility of obtaining a higher coefficient of performance compared to the standard value of 2.96 by utilizing the evaporative cooling system. This in turn reduces the electrical energy consumption and makes the devices operate in very appropriate conditions, which prolongs the life of the devices and preserves them from damage.
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Authors and Affiliations

Hakim T. Kadhim
1
Munadhil Aldamaad
1

  1. Karbala Technical Institute, Al-Furat Al-Awsat Technical University (ATU), Karbala, 56001, Iraq
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Abstract

The potential for generating electricity through solar energy makes Brazil a very promising country in this segment, with several possibilities for the use of solar energy, whether in the thermal or photovoltaic part, due to the high incidence of solar radiation throughout much of the country, especially in the Northeast region. In this study, an analysis of the perfor-mance of the organic Rankine cycle (ORC) that produces electricity using solar concentrators was performed. The fluids used in the system were classified as dry type  toluene, isobutane, isopentane, R227ea, R113, R114, R245fa and R600. During the study, the energy and exergy analysis of the system was conducted for different evaporator pressures (500−2500 kPa), and two types of solar collectors were tested (parabolic trough collector and parabolic compound collec-tor). In addition, a system case study was simulated for radiation and temperature conditions in the city of João Pessoa, Brazil. Based on this analysis, the performance of the cycle components was examined, and the first and second law effi-ciencies of the system were compared for different configurations. The solar collector (parabolic trough collector) proved to be the most suitable for the studied cycle. With the adequate selection of the refrigerant, collector and evaporation pressure, the first and second law efficiencies of the cycle improve up to 41% and 44%, respectively. For the city of João Pessoa, the highest exergy efficiency occurs in the month of January, the hottest month of the year when the sun shines brightly, and the lowest exergy efficiency occurs in the month of June.
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Authors and Affiliations

Taynara G.S. Lago
1
Beatriz R.P. Padilha
2
Felipe S. Teixeira
1
João A. Lima
1
Adriano S. Marques
1
Carlos M.S. Santos
3

  1. Department of Renewable Energy Engineering, Centre of Renewable and Alternative Energy, Federal University of Paraíba, João Pessoa – PB, Brazil
  2. Postgraduate Program in Energy Planning, Faculty of Mechanical Engineering, State University of Campinas, Campinas – SP, Brazil
  3. Centre for Exact and Technological Sciences, Federal University of Recôncavo da Bahia, Cruz das Almas –BA, Brazil
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Abstract

Foamed ceramics are widely used in construction as a building material. This article used potassium feldspar tailings as the primary raw material and added a silicon carbide (SiC) foaming agent to prepare samples through a sintering process. The impact of three factors − SiC content, sintering temperature and heat preservation time − on sample properties (such as bulk density and water absorption rate) was analyzed using a single-factor variable method. It was found that the increase in SiC content, sintering temperature, and heat preservation time increased pores inside the sample, thereby leading to a higher water absorption rate, lower compressive strength and higher mass loss rate, i.e., decreased sample performance. Overall, the optimal sintering process parameters were as follows: a SiC content of 1.0 wt%, a sintering temperature of 1,250℃ and a heat preservation time of 30 minutes. Under these conditions, the obtained sample had a bulk density of 0.54 g/cm3, a water absorption rate of 13.45%, a compressive strength of 4.75 MPa, a thermal conductivity of 0.06 W/(m·K) and an acid resistance mass loss of 1.21%, exhibiting the optimal performance. The experimental results provide appropriate SiC content and sintering parameters that can be applied in practice to obtain higher-performance foam ceramics.
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Authors and Affiliations

Haicheng Qi
1

  1. Henan Mechanical and Electrical Vocational College, Mount Taishan Road, Longhu Town, Xinzheng City, Henan 454000, China
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Abstract

This work addresses the challenges associated with one-dimensional modelling of steady transonic two-phase flows illustrated through simulations of selected flow cases of the famous Moby Dick experiment. It primarily concentrates on the method for a fast determination of the transonic trajectory. The second proposed approach allows for determining trajectories describing the transonic flow with a normal shock wave. The first method is successfully verified by comparing its results with simulation results obtained from the (widely known and thoroughly verified) Wavefront Algorithm for High-speed Aerodynamics code, utilizing the Delayed Equilibrium Model. The first method mentioned is the author's proposition that is competitive to conven-tional (time-expensive) approaches such as the Newton Critical Point or achieving a steady flow description by asymptotical convergence of the time-dependent model's solutions, and it is a completely new consistent solution method. The second pro-posed method is an adaptation of the Rankine–Hugoniot jump conditions to a two-phase flow described by the Delayed Equi-librium Model. In the case of this method, the presented here analysis and results serve only as a proof of concept. Similar methods have been described before, but the results presented in this article, obtained with the Delayed Equilibrium Model, are unique. Also, a limited but coherent model of thermodynamic properties of a superheated liquid is presented and physically justified. This model was formulated earlier and is often used, but its comprehensive derivation has not been presented before.
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Authors and Affiliations

Wojciech Angielczyk
1

  1. Bialystok University of Technology, 45A Wiejska Street, 15-351 Bialystok, Poland
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Abstract

In this work, an analytical study is carried out on the performance of copper-based nanoparticles and water in flat-plate solar collectors. The effect of copper-based nanoparticles on various thermophysical properties of collectors has been studied and compared with water under the same conditions. The effects of temperature rise parameter from 0.0018 to 0.025, volume per-centage of nanoparticles from 0 to 1 and mass flow rate in the range of 0.012 to 0.170 kg/s have been considered. The mass flow rate range covers both laminar and turbulent flow conditions. A detailed parametric study was carried out by developing appro-priate MATLAB codes for various performance and energy equations to investigate the effects of volume percentage of nano-particles and mass flow rate on the basic thermophysical properties and performance parameters, including Nusselt number, heat transfer coefficient, collector plate factor, heat removal factor, Reynolds number, collector heat gain, fluid outlet temperature and thermal efficiency. A new number has been introduced to find out the optimal value of mass flow rate for optimizing collector performance. From the analysis it was found that water collector achieved the maximum thermal efficiency of 53.7% for the highest value of mass flow rate of 0.1675 kg/s. For the nanofluid collector, the maximum efficiency is 70.5% for a nanofluid volume fraction of 0.48 and for the highest considered value of mass flow rate of 0.1675 kg/s. The nanofluid collector is predicted to provide up to 16.8% higher energy efficiency than the water collector.
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Authors and Affiliations

Vikash Kumar Gorai
1
Mukesh Kumar
1
Rahul Singh
2
Mukesh Kumar Sahu
3

  1. Cambridge Institute of Technology, Tatisilwai, Ranchi, Jharkhand, 835103, India
  2. Amity University, Ranchi, Jharkhand, 834001, India
  3. Kalinga University, Kotni, Naya Raipur, Chhattisgarh, 492101, India
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Abstract

The availability of freshwater is a significant challenge in today's world, especially in arid and coastal regions. As a solu-tion, purifying existing open water reservoirs or saline water could help bridge the gap between demand and supply. Solar distillation presents a promising method, requiring low initial investment and leaving no harmful environmental impact. However, limited yield due to the traditional design of a solar system is still a problem. Therefore, in the present study, the traditional design of the solar still, i.e. single slope solar still or conventional solar still (CSS) is modified with jute wick (MSS) at an inclination angle of 30º. The length-to-width ratio was kept at 3:1 to avoid shadows at the corners. The studies were conducted to assess how jute fibre as a wick, wind speed and solar intensity affected the CSS’s distillate production. The total yield was found to be 2.69 and 3.208 kg/m2 per day for CSS and MSS, respectively. Additionally, daily thermal efficiency was analysed to check the feasibility and practicability of the systems. It was evident that incorporating jute wick improves the thermal efficiency of CSS by 26.6%. These findings recommend MSS as a promising and economically viable solution for enhancing solar still performance.
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Authors and Affiliations

Akashdeep Negi
1
Lalit Ranakoti
1
Prabhakar Bhandari
2
Saurabh Aggarwal
3
Rajesh P. Verma
4
Ankur Singh Bist
5
Arun Uniyal
6
Shivasheesh Kaushik
7
Nikhil Kanojia
8
Ayushman Srivastav
8

  1. Department of Engineering, Graphic Era Deemed to be University, Dehradun 248 002, Uttarakhand, India
  2. Department of Mechanical Engineering, School of Engineering and Technology, K.R. Mangalam University, Gurugram, Haryana 122 103, India
  3. Department of Mechanical Engineering, Uttaranchal University, Dehradun 248 007, Uttarakhand, India
  4. Department of Aerospace Engineering, Graphic Era Deemed to be University, Dehradun 248 002, Uttarakhand, India
  5. Department of Computer Science and Engineering, Graphic Era Hill University, Bhimtal Campus, Bhimtal 263 136, Uttarakhand, India
  6. Department of Mechanical Engineering, COER University, Roorkee 247 667, Uttarakhand, India
  7. Department of Mechanical Engineering, Shivalik College of Engineering, Dehradun 248 007, India
  8. Department of Mechanical Engineering, UPES., Dehradun 248 007, India
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Abstract

This research investigates the heat transfer and fluid flow characteristics of a double pipe heat exchanger enhanced with perforated turbulators. The study focuses on the effects of varying Reynolds numbers and geometric configurations, par-ticularly the number of perforations in the inserts, on thermal performance. Using the finite volume method and Ansys Fluent simulations, the heat exchanger was analysed under different conditions, comparing the results with a smooth tube configuration. The findings reveal that the pitch ratio of 2.5 has shown the highest heat transfer capacity followed by pitch ratios of 4.5 and 6.5. Further, irrespective of relative pitch ratio, the ring with no perforations has shown the highest value of average Nusselt number and in the case of perforation, the open area ratio of 0.068 has yielded the best thermal perfor-mance.
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Authors and Affiliations

Ganga Chauhan
1
Vijay Singh Bisht
1
Prabhakar Bhandari
2
Sandeep Singh
3
Rahul Shukla
4
Lalit Ranakoti
5
Ankur Singh Bist
6

  1. Department of Thermal Engineering, Veer Madho Singh Bhandari Uttarakhand Technical University, Dehradun 248 007, Uttarakhand, India
  2. Mechanical Engineering Department, School of Engineering and Technology, K.R. Mangalam University, Gurugram, 122 103, India
  3. O.P. Jindal Global University, Sonipat 131 001, Haryana, India
  4. Mechanical Engineering Department, IET Bundelkhand University, Jhansi 284 001, Uttar Pradesh, India
  5. Department of Mechanical Engineering, Graphic Era Deemed to be University, Dehradun 248 002, Uttarakhand, India
  6. Graphic Era Hill University, Bhimtal campus, Bhimtal 26 3136, Uttarakhand, India
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Abstract

The article presents an assessment of the parameters of power quality obtained from renewable sources. The assessment was based on the Decree of the Minister of Climate and Environment of March 22, 2023 on detailed conditions for the operation of the electricity system (Dz. U. 2023 r., 819) and the EN 50160: 2010 standard – Parameters of supply voltage in public power grids. The analysis was carried out on the example of actual measurements of power quality parameters. The measurements were made with a Fluke 1760 power quality analyser. The analyser was installed at the point of connection to the renewable energy grid. The article analyses and compares renewable energy sources. The assessment of power quality parameters was carried out on the basis of the discussed analyses. The article presents the influence of seasonality on the parameters of power quality.
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Authors and Affiliations

Marta Bątkiewicz-Pantuła
1

  1. Wrocław University of Science and Technology, Faculty of Electrical Engineering, Institute of Electrical Power Engineering, Wybrzeże Wyspiańskiego Str. 27, 50-370 Wroclaw, Poland
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Abstract

To explore the performance limit of direct ammonia-fed solid oxide fuel cells based on oxygen-ion conductivity, a finite time thermodynamic model is developed. The finite time thermodynamic indexes including exergy efficiency, exergetic performance coefficient and entropy production rate are derived to evaluate the performance of direct ammonia-fed solid oxide fuel cells from multiple perspectives. Moreover, the effects of operating temperature, operating pressure, fuel utilization, electrolyte thickness and electrode porosity on exergy efficiency and exergetic performance coefficient of the studied direct ammonia-fed solid oxide fuel cells are numerically analyzed. The derived finite time thermodynamic model can be further employed to obtain optimal operating parameters and structural parameters under different application scenarios to guide engineering design and operation control.
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Authors and Affiliations

Anli Shang
1
Hanlin Song
2
Zheshu Ma
2

  1. School of Mechanical Engineering, Xijing University, Xi'an, 710123, China
  2. College of Automobile and Traffic Engineering, Nanjing Forestry University, Nanjing 210037, China
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Abstract

The main objective of this study is to investigate the effects of Cu, Al2O3, and H2O-based nanofluids on heat transfer through annulus-shaped, two concentric cylindrical regions. The quadratic convection in the flow of hybrid nanofluids in an inclined porous annulus medium is considered. The conservation laws are obeyed in a non-linear model of the flow geometry. Applying a suitable non-dimensional transformation, we solved the resultant equation using the Runge-Kutta 4th order method with a shooting technique to obtain the solution for the velocity and temperature. The flow structure and heat transfer are influenced by quadratic resistance and mixed convection mechanisms in nonlinear Boussinesq approximation, as investigated in biomed-ical devices, nuclear reactors as well as heat exchangers. The analysis demonstrates that radiation significantly affects heat transfer by enhancing the Lorentz force, which in turn dissipates the flow rate. This behaviour aligns well with the flow patterns reported in previous studies for various physical parameters.
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Authors and Affiliations

Rudrappa Mahesha
1 2
Narasappa Nalinakshi
1
Thavada Sravan Kumar
1

  1. Department of Mathematics, Atria Institute of Technology, Bengaluru 560024, KA, India
  2. Visvesvaraya Technological University, Belagavi 590018, KA, India

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4. All abbreviations should be spelled out first time they are introduced in the text. Abbreviations should also be listed in the Nomenclature.

5. The equations should be each in a separate line. Standard mathematical notation should be used. All symbols used in equations must be clearly defined. The numbers of equations should run consecutively, irrespective of the division of the paper into sections. The numbers should be given in round brackets on the righthand side of the column.

6. Particular attention should be paid to the differentiation between capital and small letters. If there is a risk of confusion, the symbols should be explained (for example small c) in the margins. Indices of more than one level (such as Bfa) should be avoided wherever possible.

7. Computer-generated figures should be produced using bold lines and characters. No remarks should be written directly on the figures, except numerals or letter symbols only. Figures should be as small as possible while displaying clearly all the information requires, and with all lettering readable. The relevant explanations can be given in the caption.

8. The figures, including photographs, diagrams, etc., should be numbered with Arabic numerals in the same order in which they appear in the text. Each figure should have its own caption explaining the content without reference to the text.

9. The figures should also be submitted as separate graphic files in either vector formats (PostScript (PS), Encapsulated PostScript (EPS), preferable, CorelDraw (CDR), etc.) or bitmap formats (Tagged Image File Format (TIFF), Joint Photographic Experts Group (JPEG), etc.), with the resolution not lower than 300 dpi, preferably 600 dpi. These resolutions refer to images sized at dimensions comparable to those of figures in the print journal. Therefore, electronic figures should be sized to fit on single printed page and can have maximum 120 mm x 170 mm.

10. The references for the paper should be numbered in the order in which they are called in the text. Calling the references is by giving the appropriate numbers in square brackets. The references should be listed with the following information provided: the author’s surname and the initials of his/her names, the complete title of the work (in English translation) and, in addition:

The references should be placed after the acknowledgment section. The references citation in the manuscript body should be numbered: [1], [2], etc. Please use the following style of references in bibliography APA – 7th ed:

Journal citation (APA – 7th ed):
[1] Król, J., & Ocłoń, P. (2019). Sensitivity analysis of hybrid combined heat and power plant on fuel and CO2 emission allowances price change. Energy Conversion and Management, 196, 127–148.
doi.org/10.1016/j.enconman.2019.05.090

[2] Zhou, Y., Bi, H., & Wang, H. (2023). Influence of the primary components of the high-speed train on fire heat release rate. Archives of Thermodynamics, 44(1), 37–61.
doi.org/10.24425/ather.2023.145876

When citing scientific papers, it is needed to provide a DOI identifier if available.
Example of citation:
• Król and Ocłoń [1] studied a hybrid CHP sensitivity on fuel and CO2 emission allowances price change.
• Zhou et al. [2] studied the influence of the primary components of the high speed train on fire heat release rate.

Book citation (APA – 7th ed):
[3] Ocłoń, P. (2021). Renewable energy utilization using underground energy systems (1st ed.). Springer Nature.
Example of citation:
• Ocłoń et al. [3] presented renewable energy systems for heating cooling and electrical energy production in buildings.

Book chapter citation (APA – 7th ed):
[4] Ciałkowski, M., & Frąckowiak, A. (2014). Boundary element method in inverse heat conduction problem. In Encyclopedia of Thermal Stresses (pp. 424–433). Springer Netherlands.
Example of citation:
• Ciałkowski and Frąckowiak [4] presented a Boundary element method application for solving inverse heat conduction problems.

Conference proceedings (APA – 7th ed):
[5] Pourghasemi, B., & Fathi, N. (2023). Validation and verification analyses of turbulent forced convection of Na and NaK in miniature heat sinks. ASME 2023 Verification, Validation, and Uncertainty Quantification Symposium, 17-19 May, Baltimore, USA.
Example of citation:
• Pourghasemi and Fathi [5] validated and verified turbulent forced convection of Na and NaK in miniature heat sinks.
For works originally published in a language other than English, the language should be indicated in parentheses at the end of the reference. Authors are responsible for ensuring that the information in each reference is complete and accurate, including the DOI number.

11. As the papers are published in English, the authors who are not native speakers of English are obliged to have the paper thoroughly reviewed language-wise before submitting for publication. When the Editors or Reviewers assess that the writing English of the manuscript is poor, the authors are obliged to correct it, and provide a Certificate of English Editing as attachment in Editorial System.

Further information

All manuscripts will undergo some editorial modification. The paper proofs (as PDF file) will be sent by e-mail to the corresponding author for acceptance, and should be returned within two weeks of receipt. Within the proofs corrections of minor and typographical errors in: author names, affiliations, articles titles, abstracts and keywords, formulas, symbols, grammatical error, details in figures, etc., are only allowed, as well as necessary small additions. The changes within the text will be accepted in case of serious errors, for example with regard to scientific accuracy, or if authors reputation and that of the journal would be affected. Submitted material will not be returned to the author, unless specifically requested. A PDF file of published paper will be supplied free of charge to the Corresponding Author. Submission of the manuscript expresses at the same time the authors consent to its publishing in both printed and electronic versions.

Transfer of Copyright Agreement

All papers are published under lincense CC BY 4.0. Once a paper has been accepted for publication, as a condition of publication, the authors are asked to send a scanned copy of the signed original of the Transfer of Copyright Agreement, signed by the Corresponding Author on behalf of all authors.

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