Farhan Lafta Rashid^a , Abbas Fadhil Khalaf^a, Ahmed Kadhim Hussein^b, Mohamed Bechir Ben Hamida ^c,d,e, Bagh Ali^f, Obai Younis^g,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.21

Abstract Convection and conduction in a fluid flow and a rigid body in contact with each other often occur in engineering situations, resulting in unsteady conjugate heat transfer (CHT). Although the analytical solutions to the separate conduction and convection issues are surprisingly straightforward, the combined conjugate heat transfer problem is substantially more complex to solve. This study investigates the CHT of a fluid (air) passing through an unbounded hemisphere. The hemisphere produces heat at a predictable and regular pace. The governing equations are solved using a finite volume system (FVS) using ANSYS Fluent V.16.0, with axisymmetric, no normal convection, and stable… More >

Aparna Kottapallia , Ramakrishna Konijeti^b,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.11

Abstract Scroll technology is widely used in refrigerators as compressors. This research paper presents the performance of a scroll-type expander derived from a scroll compressor. The research is carried out at low pressures. The effect of mechanical load on performance has been evaluated using compressed air as a working fluid. Two stages of the evaluation process are carried out in this research. In the first stage, the scroll expander model is numerically simulated using the CFD approach to predict the factors influencing the scroll expander performance. In the later stage, an experiment is carried out on a scroll-type expander prototype developed… More >

Farhan Lafta Rashid^a, Sarmad Kamal Fakhrulddin^b, Muhammad Asmail Eleiwi^c, Ahmed Kadhim Hussein^d,e, Tahseen Ahmad Tahseen^f , ObaiYounis^g,h,*, Mohammed Ibrahim Ahmedⁱ

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.6

Abstract The current study numerically analyzes the heat transfer enhancement and laminar fluid flow characteristics of four flat tubes with varying attack front airflow. The heat transfer characteristics of flat tubes are investigated in terms of Reynolds number, heat fluxes, and inclination angle. Four Reynolds numbers are studied (100, 200, 300, and 400), and three heat fluxes on the surface of the tubes are (1000, 2500, 3800 W/m2 ), the inclination angle of the four flat tubes are (30o , 45o , 90o). ANSYS Fluent software v.18 discretizes and solves the governing equations using the finite volume approach across a specified… More >

Ammar Hassan Soheel^a,*,†, Johain J. Faraj^b, Fawizea M. Hussien^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-11, 2023, DOI:10.5098/hmt.20.3

Abstract The household batch reactor using cow manure as the substrate generates methane gas used as fuel. This paper presents two-dimensional (3D) axisymmetric using commercial COMSOL 5.5 Multiphysics software. This is a computational fluid dynamics (CFD) model based on conservation equations with the chemical reaction model of anaerobic digestion (AD) processes to investigate the influence of different horizontal circular extended surfaces augmented to the inside digesters on the performance of the anaerobic digestion. Using four batch digesters, D1 with no extended surfaces and D2, D3, and D4 have augmented with four horizontal circular extended surfaces of width 2,4 and 6 cm,… More >

Shayla Islam¹, Anil Kumar Budati^1,*, Mohammad Kamrul Hasan², Saoucene Mahfoudh³, Syed Bilal Hussian Shah³

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.1, pp. 813-825, 2023, DOI:10.32604/cmes.2023.027595

Abstract In wireless communications, the Ambient Backscatter Communication (AmBC) technique is a promising approach, detecting user presence accurately at low power levels. At low power or a low Signal-to-Noise Ratio (SNR), there is no dedicated power for the users. Instead, they can transmit information by reflecting the ambient Radio Frequency (RF) signals in the spectrum. Therefore, it is essential to detect user presence in the spectrum for the transmission of data without loss or without collision at a specific time. In this paper, the authors proposed a novel Spectrum Sensing (SS) detection technique in the Cognitive Radio (CR) spectrum, by developing… More >

Xiang Su¹, Nan Li^1,*, Yuedi Hu¹, Haisheng Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2935-2956, 2023, DOI:10.32604/cmes.2023.026083

Abstract This paper introduces an aircraft wing simulation data set (AWSD) created by an automatic workflow based on creating models, meshing, simulating the wing flight flow field solution, and parameterizing solution results. AWSD is a flexible, independent wing collection of simulations with specific engineering requirements. The data set is applicable to handle computer geometry processing tasks. In contrast to the existing 3D model data set, there are some advantages the scale of this data set is not limited by the collection source, the data files have high quality, no defects, redundancy, and other problems, and the models and simulation are all… More > Graphic Abstract

Zhimin Zhao^1,2, Shangbin Wang¹, Yuanhao Tie³, Ning Feng^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1837-1850, 2023, DOI:10.32604/fdmp.2023.026814

Abstract Torquigener albomaculosus, also known as the white-spotted pufferfish, is known for creating circular nests in the underwater sand as part of the mating ritual. The nests are built by the males to attract females through the nest’s impressive design and related ability to gather fine sand particles. As the fluid-dynamic processes associated with these unique nests are still almost completely unknown, in the present study, an analysis has been conducted to investigate how the geometric parameters related to the nest design influence the fluid velocity in its center. For this reason, a geometric model of the nest consisting of 24… More > Graphic Abstract

Changrong Zhang, Hongtao Guo, Li Yu, Binbin Lv, Hongya Xia^*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1743-1758, 2023, DOI:10.32604/cmes.2023.025528

Abstract This study presents a high-speed geometrically nonlinear flutter analysis calculation method based on the high-precision computational fluid dynamics/computational structural dynamics methods. In the proposed method, the aerodynamic simulation was conducted based on computational fluid dynamics, and the structural model was established using the nonlinear finite element model and tangential stiffness matrix. First, the equilibrium position was obtained using the nonlinear static aeroelastic iteration. Second, the structural modal under a steady aerodynamic load was extracted. Finally, the generalized displacement time curve was obtained by coupling the unsteady aerodynamics and linearized structure motion equations. Moreover, if the flutter is not at a… More > Graphic Abstract

Aliasghar Azma¹, Ramin Kiyanfar², Yakun Liu^1,*, Masoumeh Azma^3,*, Di Zhang¹, Ze Cao¹, Zhuoyue Li¹

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 1711-1733, 2023, DOI:10.32604/cmc.2023.036680

Abstract Various regions are becoming increasingly vulnerable to the increased frequency of floods due to the recent changes in climate and precipitation patterns throughout the world. As a result, specific infrastructures, notably bridges, would experience significant flooding for which they were not intended and would be submerged. The flow field and shear stress distribution around tandem bridge piers under pressurized flow conditions for various bridge deck widths are examined using a series of three-dimensional (3D) simulations. It is indicated that scenarios with a deck width to pier diameter (Ld/p) ratio of 3 experience the highest levels of turbulent disturbance. In addition,… More >

Jian Yao, Fayi Yan^*, Xuejian Pei

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1425-1445, 2023, DOI:10.32604/fdmp.2023.025282

Abstract Proton exchange membrane fuel cells (PEMFCs) are largely used in various applications because of their pollution-free products and high energy conversion efficiency. In order to improve the related design, in the present work a new spiral flow field with a bypass is proposed. The reaction gas enters the flow field in the central path and diffuses in two directions through the flow channel and the bypass. The bypasses are arranged incrementally. The number of bypasses and the cross-section size of the bypasses are varied parametrically while a single-cell model of the PEMFC is used. The influence of the concentration of… More > Graphic Abstract