Applied sciences

Archives of Thermodynamics

Content

Archives of Thermodynamics | 2024 | vol. 45 | No 4 (in progress)

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Abstract

Non-invasive real-time measurements of phase content in the reservoir fluid are highly advantageous in the oil and gas industry and remain a current research topic. The paper presents an innovative, self-designed multi-electrode capacitance meter intended for detecting multiphase flow patterns in a low-permittivity medium, such as the reservoir fluid. The ca-pacitance sensor is built with delta-sigma charge modulators capacitance-to-digital converters. Machine learning is applied to convert the capacitance measurements into a tomographic image of the flow pattern. At present, the meter is built with eight electrodes. It is shown that the measurements are repeatable and have a good signal-to-noise ratio. The implemented neural network is capable of correctly reconstructing the tomographic images for a test tube filled with reservoir fluid and placed in various locations inside the test section.
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Authors and Affiliations

Remigiusz Ornowski
1 2
Marcin Lackowski
1
Roman Kwidzinski
1

  1. Institute of Fluid Flow Machinery, Polish Academy of Sciences, Heat Transfer Department, Fiszera 14, 80-231 Gdańsk, Poland
  2. TERCJA Measuring and Computer Systems, Dywizjonu 303 5B/24, 80-462 Gdańsk, Poland
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Abstract

Bioenergy carbon capture technology (BioCCS or BECCS) plays a key role in the European Green Deal, which aims to decarbonize industry and energy sectors, resulting in the production of energy with negative CO2 emissions. Due to the biogenic origin of carbon contained in municipal solid waste (MSW), the application of carbon capture in waste incinera-tion plants can be classified as BioCCS. Thus, this technology has attracted scientists' attention recently since it reduces excessive waste and emissions of carbon dioxide. Currently, there are four incineration plants in the Netherlands, Norway and Japan, in which CO2 capture is implemented; however, they are based on the post-combustion technique since it is the most mature method and not requires many changes in the system. Nevertheless, the separation of CO2 from the flue gas flow, which contains mostly nitrogen, is complex and causes a large drop in the total performance of the system. Oxy-fuel combustion technology involves the replacement of air as an oxidizer into high purity oxygen and recirculated exhaust gas. As a result, CO2-rich gas is produced that is practically ready for capture. The main goal of the study is to develop a math-ematical model of oxy-waste combustion to answer the research questions, such as how the composition of oxidant that is supplied to the process affects the combustion performance. The model includes all important processes taking place within the chamber, such as pyrolysis, char burnout and gas combustion over the grate. The results of the work will contribute to the development of oxy-waste incineration plants and will be useful for design purposes.
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Authors and Affiliations

Paulina Copik
1
Andrzej Szlęk
1
Mario Ditaranto
2

  1. Department of Thermal Technology, Silesian University of Technology, Konarskiego 22, Gliwice 44-100, Poland
  2. SINTEF Energy Research, Sem Sælands vei 11, 7034 Trondheim, Norway
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Abstract

Using oxygenated alternative fuels in compression ignition (CI) engines is feasible for energy security problems and cli-mate change. Alcohols are regarded as alternative fuels for compression ignition engines because of their excellent physi-cochemical features, emission, and combustion characteristics. Research on alcohols and their additions has progressed significantly in recent years. Several researchers have examined the combined effect of higher alcohol with diesel and their impact and challenged that concentrations of higher alcohol reduce harmful particulate emissions in CI engines. This paper mainly focused on the performance and emissions properties of higher alcohols like butanol and pentanol. Alcohol has a low energy content, typically affecting engine brake-specific fuel consumption (BSFC). Low-temperature combustion (LTC) in compression ignition engines can lower NOx and smoke emissions, and improve the efficiency of the engine. LTC is done by combining higher alcohol with increased exhaust gas recirculation (EGR) rate and retarded fuel injection timing. The higher alcohol, along with the oxygen in the fuel reduces exhaust fumes, improves the air/fuel mixture by providing a longer ignition delay (ID), and can replace the fossil fuel like diesel (partially or whole) to allow efficient and clean combustion in CI engines. Finally, several significant findings and comments are provided regarding potential ave-nues for experimental research and future development. According to thorough analysis, bio-alcohols are considered to be a substitute fuel for CI engines.
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Authors and Affiliations

Deepak Kumar
1
Naveen Kumar
2
Rajiv Chaudhary
1

  1. Department of Mechanical Engineering, Delhi Technological University, New Delhi, India, 110042
  2. Centre for Advanced Studies and Research in Automotive Engineering, Delhi Technological University, Delhi, India, 110042
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Abstract

The ongoing trend of miniaturization of electronic devices, including computer processors, high-speed servers and micro-electro-mechanical system devices, should go hand in hand with their improved performance. However, managing heat remains a major challenge for these devices. In the present study, a numerical investigation was done on a micro-channel heat sink with an open-stepped micro-pin fin heat sink with various arrangements through ANSYS software. Pin fin was varied in a fashion of increasing and decreasing. The working fluid opted for was water in a single phase. The analysis takes into account varying thermo-physical properties of water. The operating parameters, i.e. the Reynolds number was taken as 100–350 and heat flux as 500 kW/m2. Arrangements selected were staggered and inline. Observations revealed that the staggered 2 arrangement has shown better thermal performance than other arrangements within the entire investigated range of Reynolds numbers because of the effective mixing of fluids. Furthermore, the inline configuration of micro pin fin heat sink has the worst performance. It is interesting to note that a very small difference was observed in the heat transfer capability of both staggered configurations, while the pressure drop in the staggered 2 arrangement has shown an elevated value at a higher Reynold number value compared to the staggered 1 arrangement.
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Authors and Affiliations

Prabhakar Bhandari
1
Vineet Sharma
2
Lalit Ranakoti
3
Vijay Singh Bisht
4
Manish Kumar Lila
5
Shivasheesh Kaushik
6
Nikhil Kanojia
7
Ayushman Srivastava
7
Bhupendra Kumar
8
Shailesh Ranjan Kumar
9
Manish Kumar
10
Ashwarya Raj Paul
11

  1. Department of Mechanical Engineering, School of Engineering and Technology, K. R. Mangalam University, Gurugram, Haryana-122103, India
  2. Department of Electrical Engineering, Poornima College of Engineering, Jaipur-302033, India
  3. Department of Mechanical Engineering, Graphic Era Deemed to University, Clement Town, Dehradun, Uttarakhand-248002, India
  4. Department of Thermal Engineering, Veer Madho Singh Bhandari Uttarakhand Technical University, Dehradun, Uttarakhand-248007, India
  5. Department of Mechanical Engineering, Graphic Era Hill University, Dehradun, Uttarakhand-248002, India
  6. Department of Mechanical Engineering, Shivalik College of Engineering, Dehradun, India
  7. Department of Mechanical Engineering, U.P.E.S, Dehradun, India
  8. Department of Mechanical Engineering, Dr. A.P.J.A.K.I.T. Tanakpur, India
  9. Department of Mechanical Engineering, Motihari College of Engineering, Motihari, India
  10. Department of Mechanical Engineering, Bakhtiyarpur College of Engineering, Bakhtiyarpur Dedaur, Bakhtiyarpur, Patna, India
  11. Department of Mechanical Engineering, V.I.T., Vellore, India
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Abstract

This study examines a steady laminar Casson fluid flow induced by a semi-infinite vertical plate under the impact of the Darcy-Forchheimer relation and thermal radiation. The features of mixed convection, cross-diffusion, radiation absorption, heat generation, chemical reactions and viscous dissipation are also considered to explain the transport phenomenon. The resultant system of equations, concerned with the problem under consideration, is transformed into a group of non-linear ordinary differential equations (ODEs) by means of similarity variables. The bvp4c method, an instrument popular for its numerical accomplishments, is utilized to solve this problem. The effect of flow parameters on heat transfer, concentration and velocity is evaluated via diagrams. To validate our code, we have compared the present outcomes to the prevenient literature, and stable consent has been detected. Moreover, the friction coefficient Cfx, Nusselt number Nux, and Sherwood number Shx are also computed to assess velocity gradient, efficiency of heat transfer and mass transfer process, respec-tively.
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Authors and Affiliations

Sonam
1
Rajendra Singh Yadav
1

  1. University of Rajasthan, Department of Mathematics, Jaipur, Rajasthan-302004, India
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Abstract

In this paper, the thermal instability of a three-dimensional boundary layer axisymmetric stagnation point flow towards a heated horizontal rotating disk is considered. A large number of works have been done on stability analysis. However, they did not check the thermal stability of the non-parallel-flow in the face of small disturbances that occur in the vicinity of the heated rotating disk. The governing equations of the basic flow are reduced to three coupled nonlinear partial differ-ential equations, and solved numerically with the fourth-order Runge-Kutta method. Thermal stability is examined by making use of linear stability theory based on the decomposition of the normal mode of Görtler-Hammerlin. The resulting eigenvalue problem is solved numerically using a pseudo-spectral method based on the expansion of Laguerre’s polyno-mials. The obtained results are discussed in detail through multiple configurations. As the main result, for large Prandtl numbers (Pr), the rotation disk parameter (Ω) has a destabilizing effect while for small Pr (around the unity) it tends to stabilize the basic flow. It was found that as the disk radius r→0, the flow is linearly stable, and the disturbances grow rapidly away from the stagnation point. For low values of Pr, the flow becomes more stable, and strong thermal gradients are necessary to destabilize it. However, an increase in Pr leads to a significant expansion of the instability region.
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Authors and Affiliations

Samir Mamache
1
Fatsah Mendil
1
Faiçal Nait Bouda
1

  1. Université de Bejaia, Faculté de Technologie, Laboratoire de Mécanique, Matériaux et Energétique (L2ME), 06000 Bejaia, Algeria
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Abstract

The paper presents the results of analysis of thermal-flow processes in the ejector-condenser for selected geometrical param-eters using CFD (Computational Fluid Dynamics) methods. The ejector-condenser is the water-driven, two-phase ejector responsible for creating a sub-pressure allowing exhaust gases (steam and CO2 mixture) to be entrained, condensing steam, and then increasing the pressure above the atmospheric conditions. The axisymmetric numerical model was developed to take into account multiphase, turbulent flow with steam condensation in the presence of inert gas. The influence of the selected geometrical parameters, such as the motive nozzle's and mixing chamber's diameters on the ejector performance was investi-gated. CFD analysis results are presented in the form of developed scalar distributions as well as pressure, temperature and steam mass flow changes along the flow path. Performances for different geometry modes were calculated and compared using parameters such as compression ratio, expansion ratio, mass entertainment ratio and condensation efficiency. The max-imum achieved compression ratio for the analyzed geometrical variants is 1.113 for the assumed mass entertainment ratio of 0.0295. The condensation efficiency varies in a range of 49.6%–91.4% depending on motive fluid inlet conditions and geom-etry mode.
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Authors and Affiliations

Tomasz Kuś
1
Paweł Madejski
1

  1. AGH University of Krakow, Faculty of Mechanical Engineering and Robotics, Department of Power Systems and Environmental Protection Facilities, al. Mickiewicza 30, 30-059 Kraków, Poland
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Abstract

In this study, the thermodynamic analysis of a combined cycle gas turbine integrated with post-combustion carbon capture and storage using the solvent method is performed. The syngas obtained from the gasification of sewage sludge is mixed with methane and nitrogen-rich natural gas fuels at different proportions, used in the gas turbine, and the properties of fuel and flue gases are analyzed. The flue gas obtained from the fuel mixture is passed through the post-combustion carbon capture and storage at various load conditions to assess the heat and electricity required for the carbon capture process. The solvent used for the carbon capture from flue gases enables CO2 capture with the high efficiency of 90%. With the calculated results, the load conditions of flue gas using fuel mixtures are identified, which reduces the heat and power demand of post-combustion carbon capture and storage and provides the possibility to achieve neutral emission. The impact of selected operating conditions of post-combustion carbon capture and storage on the CO2 emission reduction process and on the power plant performances is investigated. Considering the factors of electricity generation, energy efficiency, heat supply to the consumers, operating load of post-combustion carbon cap-ture and storage and CO2 emission, the 50% mixture of syngas with both fuels performs better. Also, the use of a mixture of 2-amino-2methyl-1-propanol and piperazine with reboiler duty 3.7 MJ/kgCO2 in post-combustion carbon capture and storage slightly enhanced the performance of the power plant compared to the use of monoethanolamine with reboiler duty 3.8 MJ/kgCO2.
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Authors and Affiliations

Navaneethan Subramanian
1
Paweł Madejski
1

  1. AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, al. Mickiewicza 30, 30-059 Kraków, Poland
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Abstract

This paper analyses the inverse marching method used to determine the thermal stresses on the inner surface of a thick-walled cylindrical element not weakened by holes in the transient state. The heat conduction problem was considered one-dimensional, i.e. it was assumed that heat is transferred only in the radial direction. The method is based on measuring the temperature inside the pipeline wall at a single point and assuming that the pipeline is thermally insulated. The paper undertook an evaluation of the influence of the measuring point's distance from the inner surface, the number of control volumes into which the inverted area was divided and the length of the time step on the accuracy of the calculated temper-ature, heat transfer coefficient and thermal stresses on the inner surface of the pressure element. Verification was performed by comparing the calculation results obtained from the direct analytical method perturbed by random errors with those obtained from the numerical inverse step method.
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Authors and Affiliations

Magdalena Jaremkiewicz
1

  1. Cracow University of Technology, Faculty of Environmental and Energy Engineering, ul. Warszawska 24, Cracow 31-155, Poland
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Abstract

Electrification of district heating and deep integration of sectors of national economies are fundamental elements of the future smart energy systems. This paper discusses the problem of optimal sizing of large-scale high-temperature heat pumps using treated sewage water as a heat source in a coal-fired district heating system. The study presents an approach to modelling of heat pump system that enables techno-economic analysis for investment decision making. Such analysis is enabled by a black-box-type identification model of the selected industrial heat pump. The model was developed based on the data generated by physical modelling of the heat pump using Ebsilon Professional software. In addition, it is proposed that the heat pump system is integrated with a dedicated photovoltaic power plant. The case study takes into consideration site-specific technical, economic, ecological, and legal constraints, weather conditions, hydraulic performance of the heat-ing network, and variability of loads within the sewage and the district heating systems. The results revealed that the proposed modelling approach is effective regarding multiple simulations and system optimisation. In addition, it was found that large-scale heat pump projects can be technically feasible and profitable if the heat pump is appropriately sized and operated. In the given case, the optimum size of the heat pump for a city of around 180 000 inhabitants is around 12 MW under maximum winter load.
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Authors and Affiliations

Jacek Kalina
1

  1. Silesian University of Technology, Konarskiego 22, Gliwice 44-100, Poland
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Abstract

The paper presents the results of experimental research on a pumping engine with the low-boiling medium HFE-7100. The research was conducted in a micro-ORC system with an output of about 2.5 kWe. Among other factors, the impact of working medium temperature and pump rotational speed on the operating parameters of the gear pump and pumping engine is analyzed. The research shows that increasing the rotational speed and HFE-7100 temperature resulted in an increase in the power consumed by the pump drive and an increase in the effective power of the pump. The increase in the effective power of the pump was greater than the electrical power consumption of the pump drive, resulting in an increase in the volumetric efficiency of the pump. It has been established that, at a constant pump rotational speed of 2000 rpm, increasing the average temperature of HFE-7100 by 27 K from approximately 304 K resulted in a 4% increase in the pump's volu-metric efficiency to 80%. It has been established that, for any value of pump rotational speed and working fluid tempera-ture, there exists an optimal effective power value for the pump at which the pumping engine achieves the maximum efficiency.
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Authors and Affiliations

Tomasz Z. Kaczmarczyka
1

  1. Institute of Fluid-Flow Machinery, Polish Academy of Sciences, ul. Fiszera 14, Gdańsk 80-231, Poland
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Abstract

The outcomes of gas-dynamic computations for the low-pressure cylinder component of the K-1000-60/1500-2M type low-speed steam turbine intended for use in nuclear power plants are presented in the paper. Various strategies for enhancing the low-pressure cylinder, incorporating a novel approach, which was not previously employed in low-speed high-power steam turbines, have been identified. The flow part redesign has been carried out through the comprehensive methodology and software imple-mented in the IPMFlow package. This methodology encompasses gas-dynamic computations of varying complexities and ana-lytical profiling methods for spatial blade row shapes based on a limited set of parameterized values. Real thermodynamic prop-erties of water and steam were considered in 3D turbulent flow calculations. The final stage involved end-to-end 3D computations of the 7-stage low-pressure cylinder, employing parallel computing technology. The results indicate that the innovative solutions incorporated in the developed low-pressure cylinder led to a substantial increase in both efficiency and power.
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Authors and Affiliations

Roman Rusanov
1
Viktor Subotin
1
Andrii Rusanov
1
Viktor Shvetsov
1
Serhii Palkov
1
Ihor Palkov
1
Marina Chugay
1

  1. Pidhornyi Institute of Power Machines and Systems of the National Academy of Sciences of Ukraine
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Abstract

In Poland, heating systems using renewable energy sources have gained importance in construction projects, especially in newly designed buildings. This is mainly due to the Regulation of the Minister of Infrastructure, which sets technical conditions for buildings. As of December 31, 2020, the primary energy index for newly designed single-family buildings should not exceed 70 kWh/(m2year). This requires efficient energy sources in building design. Renewable energy installations have significantly lower primary energy utilization rates than fossil fuel systems, making them the preferred choice. In a facility in Batowice near Krakow, a hybrid energy system with ground-source and air-source heat pumps has been installed. These pumps are powered by electricity from a photovoltaic installation connected to the grid. The study aims to determine the optimal heat pump choice based on the facility’s conditions and optimize electricity consumption from the photovoltaic installation. Both heat pumps showed similar efficiencies during the heating season from December 2022 to March 2023: the ground-source heat pump achieved an annual coefficient of performance of 2.69, and the air-source heat pump achieved a seasonal coefficient of perfor-mance of 2.63. Given the high non-renewable primary energy factor for grid electricity, the feasibility of replacing gas boilers with heat pumps requires careful evaluation. The results indicate that integrating a heat pump with a photovoltaic installation substantially reduces the primary energy utilization index, supporting climate protection and the advancement of renewable energy sources. However, heat pumps alone may not be sufficiently efficient without the support of a PV installation.
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Authors and Affiliations

Marcin Kazimierz Turoń
1

  1. Cracow University of Technology, ul. Warszawska 24, Cracow 31-155, Poland
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Abstract

The introduction of new material solutions into the BIPV (Building Integrated Photovoltaics) requires the need to check their suitability in this area. This especially applies to resistance to weather conditions and resistance to UV radiation. The authors conducted a series of tests on samples of photovoltaic modules made using a composite lamination technology based on glass fibres and hardened resins. The resistance of such a structure to atmospheric conditions and degradation by UV rays was investigated. Both of these areas have a significant impact on the efficiency of such a solution in terms of converting solar energy into electricity and the service life of the solution. It was found that delamination of the composite PV modules can be avoided in the case of some studied resins (e.g. LG 385).
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Authors and Affiliations

Piotr Sprawka
1
Patryk Chaja
2
ORCID: ORCID
Paweł Wujek
1

  1. ElectroTile Sp. z o.o., Pulawska 427, 02-801 Warszawa, Poland
  2. Institute of Fluid-Flow Machinery Polish Academy of Sciences, Fiszera 14, 80-231 Gdańsk, Poland
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Abstract

This paper investigates the effects of an inclined magnetic field on heat and mass transfer in turbulent squeeze flow of a viscoelastic fluid with an upper-convected Maxwell model. Squeezing flow is an important phenomenon in various industrial and mechanical processes related to flows between parallel surfaces. Mathematical modelling for the law of conservation of mass, momentum, heat and concentration of nanoparticles is executed. The study employs a system of partial differential equations to describe the flow issue. Governing nonlinear partial equations are reduced into nonlinear ordinary differential equations. The modelled equations are then solved numerically by utilizing the efficient Adams-Moulton method of the fourth order based on the shooting technique using the Fortran programming language. Numerical results are compared with another numerical approach and an excellent agreement is observed. The effects of various factors on the non-dimensional velocity, temperature, and concentration patterns are presented using graphs, while tables are used to assess the numerical values of the skin friction, Nusselt and Sherwood numbers. It is found that the temperature profile decreases as the compression parameter increases but increases with an increase in the Eckert number. The results of this study could be useful in designing heat and mass transfer equipment for applications in viscoelastic fluid flows under an inclined magnetic field.
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Authors and Affiliations

Sreenivasa Somireddy Reddy
1
Kamatam Govardhan
2
Ganji Narender
3
Santoshi Misra
4

  1. Department of Humanities and Science (Mathematics), Viganana Bharathi Institute of Technology, Hyderabad-501301, Telangana, India
  2. Department of Mathematics, GITAM University, Hyderabad-502329, Telangana, India
  3. Department of Humanities and Sciences (Mathematics), CVR College of Engineering, Hyderabad-501510, Telangana, India
  4. Department of Mathematics, St. Ann’s College for Women, Hyderabad, Telangana, India
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Abstract

The aim of this research paper is to investigate the rotational flow of an unsteady magnetohydrodynamic heat and mass transfer flow due to convection over a vertical porous semi-infinite plate. The plate undergoes continuous circular motion, maintaining a constant velocity. To achieve this, we worked on both numerical methods and analytical techniques, particularly utilizing perturbation methods to solve the governing partial differential equations. Consequently, we derive an expression for the Nusselt and Sherwood numbers. We delve into the analysis of the velocity profile, temperature distribution, and concentration variation, exploring their behaviour under different physical parameters, including the magnetic field parameter, Grashof num-ber, Soret number and Schmidt number, as well as the Prandtl number. Our findings reveal that the velocity increases with rising values of Grashof, modified Grashof and Soret numbers, whereas it decreases with declining values of the magnetic field parameter, Prandtl number and Schmidt number. Additionally, as rotation gradually intensifies, the fluid velocity closely follows the boundary and becomes negligible as it moves away from it. To facilitate a comprehensive examination of the fluid flow and heat and mass transfer characteristics, we employ graphical representations. Furthermore, this paper offers an in-depth discussion of the underlying physical aspects and their implications.
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Authors and Affiliations

Mohanasundaram Narmatha
1
R. Kavitha
2

  1. Department of Mathematics, KPR Institute of Engineering and Technology, Coimbatore, India
  2. Department of Mathematics and Statistics, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu, India
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Abstract

The use of different turbulators in solar air heaters can significantly impact their thermal and hydraulic performance. This study compares solar air heaters equipped with W-contoured, taper-contoured, and reverse taper-contoured turbulators. It examines heat transfer coefficients, pressure drops, velocity contours, turbulent kinetic energy contours, and thermal perfor-mance factors for these systems under varying operating conditions. The air Reynolds number ranges from 4000 to 18 000, while design parameters such as relative roughness height and relative pitch ratio remain constant for accurate comparison. The simulations were conducted with a uniform heat flux of 1200 W/m2. The W-shaped contour roughness achieved the greatest heat transfer coefficient, surpassing both the tapered and reverse tapered configurations. In terms of friction factor, the tapered contour on the absorber plate led, followed by the reverse tapered and W-shaped contours. Overall, the W-shaped contour delivered the best performance. At lower Reynolds numbers, the reverse tapered contour outperformed the tapered contour, whereas at higher Reynolds numbers, the tapered contour showed superior performance compared to the reverse tapered contour.
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Authors and Affiliations

Abhishek Ghildyal
1
Vijay Singh Bisht
1
Prabhakar Bhandari
2
Subham Thapliyal
3
Shivasheesh Kaushik
4
Lalit Ranakoti
5
Raghubeer Singh Bangari
6
Ayushman Srivastav
7
Nikhil Kanojia
7
Ashwarya Raj Paul
8

  1. Department of Mechanical Engineering, Veer Madho Singh Bhandari Uttarakhand Technical University, Dehradun 248007, India
  2. Department of Mechanical Engineering, School of Engineering and Technology, K.R. Mangalam University, Gurugram, Haryana 122103, India
  3. Department of Mechanical Engineering, Uttaranchal University, Dehradun, India
  4. Department of Mechanical Engineering, Shivalik College of Engineering Dehradun, India
  5. Department of Mechanical Engineering, Graphic Era Deemed to Be University, Dehradun 248002, Uttarakhand, India
  6. Department of Mechanical Engineering, Graphic Era Hill University, Dehradun 248002, Uttarakhand, India
  7. Department of Mechanical Engineering, U.P.E.S., Dehradun, India
  8. Department of Mechanical Engineering, Vellore Institute of Technology, Vellore, India
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Abstract

Enhancements in gas turbine blade cooling techniques, such as film cooling, have significantly advanced the aerothermal effi-ciency of turbines, especially in transportation sectors like aeronautics and automotive industries. This study aims to enhance turbine blade cooling by incorporating an obstruction at the jet exit. The vortex generator angle has been modified to 25°, 45°, 60°, 90° and 110°. These five designs were assessed in comparison to the conventional cylindrical hole configurations. Two injection ratios (M = 0.25, and M = 0.5) were studied within the ANSYS CFX 16 software, utilizing the finite volume method to solve the average Reynolds equations and the energy equation. The findings show qualitative alignment with experimental data for the base scenario, indicating that the vortex generator angle notably amplifies film cooling effectiveness. Typically, the vortex generator configured at 90° exhibits a stronger mixing capability compared to the other cases and cylindrical design.
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Authors and Affiliations

Mohammed Larbi
1
Khadidja Boualem
2
Siham Kerrouz
2
Fatima Benali Kouchih
1
Tayeb Yahiaoui
1
Abbes Azzi
1

  1. University of Sciences and Technology of Oran - Mohammed Boudiaf, P.O. Box 1505, El-M’Naouer, 31000, Oran, Algeria
  2. University of Relizane, Algeria
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Abstract

The paper presents an analysis of a transition from a coal-fired power plant to a nuclear unit. The main focus is set on the extensive usage of the existing parts of the already operating system. The key problem is the correct matching of a nuclear reactor and the steam island. It is assumed here that the reactor module operates under nominal conditions and the steam turbine is adapted to fit the reactor. The paper describes the numerical model of the steam turbine cycle for the off-design simulations. The developed model allows us to determine the changes in the steam cycle in order to match the required water and steam temperature values at the inlets and the outlets of the steam generator. The paper presents the suggested modifications and the evaluation of the operation after the transition.
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Authors and Affiliations

Wojciech Kosman
1
Henryk Łukowicz
1
Łukasz Bartela
1
Dorota Homa
1
Jakub Ochmann
1

  1. Silesian Univeristy of Technology, ul. Konarskiego 18, Gliwice 44-100, Poland
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Abstract

In this study, collectors with two different designs as solar air heaters were examined. Both collectors have equal dimensions and panels with the same features are placed inside. A zigzag strip is placed within the cavities of the collec-tor I panel. The inside of the cavities of the collector II panel is left empty. The thermal efficiency of the panel was observed by providing air flow from the bottom of both collectors. A good design is essential for an efficient collector. As a result of the studies carried out, according to the second law of thermodynamics, the efficiency of collector I, which has a zigzag inside the panel, is between 20.2% and 38.8%, whereas the efficiency of collector II, which is hollow inside the panel, varies between 17% and 32.2%.
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Authors and Affiliations

Murat Kaya
1

  1. Hitit University Mechanical Engineering, Çorum 1900, Turkey

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The list should begin with Latin symbols in alphabetical order followed by Greek symbols also in alphabetical order and with a separate heading. Subscripts and superscripts should follow Greek symbols and should be identified with separate headings. Physical quantities should be expressed in SI units ( Système International d’Unités). In the template a dedicated area is created to put the nomenclature.

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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