Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >

Karam H. Mohammed¹, Ashraf E. Al-Mirani¹, Bashar Mahmood Ali², Omar Rafae Alomar^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 839-854, 2024, DOI:10.32604/fhmt.2024.052671

Abstract This work involves an experimental study on the performance of automobile air-conditioning systems by adding AlO nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed cooling of refrigeration systems and to compare it with the system operated using only oil. The AlO nanoparticles have been added to the oil compressor for different ranges of mass concentration (Ø = 0.1%, Ø = 0.15% and Ø = 0.2%). The stability of AlO nanoparticles has been tested by direct observation for different time periods. The results indicated that the air conditioning system that More >

Bo Hui^1,2,*, Shengneng Zhu², Sijun Su², Wenjuan Li²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 855-868, 2024, DOI:10.32604/fhmt.2024.051387

Abstract The structure of the concave-convex plates has proven to be crucial in optimizing the internal flow characteristics of the electrolyzer for hydrogen production. This paper investigates the impact of the gradual expansion angle of the inlet channel on the internal flow field of alkaline electrolyzers. The flow distribution characteristics of concave-convex plates with different inlet angle structures in the electrolytic cell is discussed. Besides, the system with internal heat source is studied. The results indicate that a moderate gradual expansion angle is beneficial for enhancing fluid uniformity. However, an excessively large gradual expansion angle may More > Graphic Abstract

M. Sridevi¹, B. Shankar Goud², Ali Hassan^3,4,*, D. Mahendar⁵

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 939-953, 2024, DOI:10.32604/fhmt.2024.050929

Abstract This study intends to evaluate the influence of temperature stratification on an unsteady fluid flow past an accelerated vertical plate in the existence of viscous dissipation. It is assumed that the medium under study is a grey, non-scattered fluid that both fascinates and transmits radiation. The leading equations are discretized using the finite difference method (FDM). Using MATLAB software, the impacts of flow factors on flow fields are revealed with particular examples in graphs and a table. In this regard, FDM results show that the velocity and temperature gradients increase with an increase of Eckert More >

Yasushi Koito^1,*, Akira Fukushima²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 869-887, 2024, DOI:10.32604/fhmt.2024.050910

Abstract Thermal and fluid-flow characteristics were numerically analyzed for ultra-thin heat pipes. Many studies have been conducted for ultra-thin heat pipes with a centered wick structure, but this study focused on separated wick structures to increase the evaporation/condensation surface areas within the heat pipe and to reduce the concentration of heat flux within the wick structure. A mathematical heat-pipe model was made in the three-dimensional coordinate system, and the model consisted of three regions: a vapor channel, liquid-wick, and container wall regions. The conservation equations for mass, momentum, and energy were solved numerically with boundary conditions… More >

Abdellatif El Hannaoui^1,*, Rachid Boutarfa¹, Chadia Haidar²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 733-746, 2024, DOI:10.32604/fhmt.2024.050520

Abstract The proposed work focuses on the in-depth study of convective heat transfer in the unconfined air gap of a discoidal rotor-stator system. The rotary cooling mechanism is achieved by the injection of two air jets, while the cavity geometry is characterized by a dimensionless parameter G. The numerical analysis primarily concentrated on the effect of flow velocity and rotation on the heat exchange process. More precisely, the range of analysis extends from the rotational Reynolds number to , while varying the Reynolds value of the jet in a range from to . To carry out More >

Farman Saifi^1,*, Mohd Javaid¹, Abid Haleem¹, S. M. Anas^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2747-2777, 2024, DOI:10.32604/cmes.2024.051490

Abstract Recent industrial explosions globally have intensified the focus in mechanical engineering on designing infrastructure systems and networks capable of withstanding blast loading. Initially centered on high-profile facilities such as embassies and petrochemical plants, this concern now extends to a wider array of infrastructures and facilities. Engineers and scholars increasingly prioritize structural safety against explosions, particularly to prevent disproportionate collapse and damage to nearby structures. Urbanization has further amplified the reliance on oil and gas pipelines, making them vital for urban life and prime targets for terrorist activities. Consequently, there is a growing imperative for computational… More >

Jie-Di Weng¹, Yong-Zheng Jiang^1,*, Long-Chao Chen¹, Xu Zhang¹, Guan-Yong Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2533-2557, 2024, DOI:10.32604/cmes.2024.051232

Abstract Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved boundaries is vital in aircraft design, ocean, and construction engineering. However, current methods such as Lattice Boltzmann (LBM) and the immersion boundary method based on solid ratio (IMB) have limitations in identifying custom curved boundaries. Meanwhile, IBM based on velocity correction (IBM-VC) suffers from inaccuracies and numerical instability. Therefore, this study introduces a high-accuracy curve boundary recognition method (IMB-CB), which identifies boundary nodes by moving the search box, and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,… More > Graphic Abstract

Abuzar Abid Siddiqui¹, Mustafa Turkyilmazoglu^2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2487-2512, 2024, DOI:10.32604/cmes.2024.050525

Abstract The physical problem of the thin film flow of a micropolar fluid over a dynamic and inclined substrate under the influence of gravitational and thermal forces in the presence of nanoparticles is formulated. Five different types of nanoparticle samples are accounted for in this current study, namely gold Au, silver Ag, molybdenum disulfide M_oS₂, aluminum oxide Al₂O₃, and silicon dioxide SiO₂. Blood, a micropolar fluid, serves as the common base fluid. An exact closed-form solution for this problem is derived for the first time in the literature. The results are particularly validated against those for the Newtonian fluid… More >

Mengdong An¹, Weiyuan Zhong¹, Wei Xu², Xiuli Wang^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1331-1349, 2024, DOI:10.32604/fdmp.2023.046604

Abstract The reactor coolant pump (RCP) rotor seizure accident is defined as a short-time seizure of the RCP rotor. This event typically leads to an abrupt flow decrease in the corresponding loop and an ensuing reactor and turbine trip. The significant reduction of core coolant flow while the reactor is being operated at full load can have very negative consequences. This potentially dangerous event is typically characterized by a complex transient behavior in terms of flow conditions and energy transformation, which need to be analyzed and understood. This study constructed transient flow and rotational speed mathematical More > Graphic Abstract