Hongen Li, Hongjuan Ren^*, Cong Li, Yecui Yan

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 921-941, 2025, DOI:10.32604/fhmt.2025.066512 - 30 June 2025

Abstract The flow field architecture of the proton exchange membrane fuel cell (PEMFC) cathode critically determines its performance. To enhance PEMFC operation through structural optimization, trapezoidal obstacles were implemented in the cathode flow channels. The height dependence of these obstacles was systematically investigated, revealing that a 0.7 mm obstacle height enhanced mass transfer from channels to the gas diffusion layer (GDL) compared to conventional triple-serpentine designs. This configuration achieved a 12.08% increase in limiting current density alongside improved water management. Subsequent studies on obstacle distribution density identified 75% density as optimal, delivering maximum net power density More >

Aiguo Li¹, Yunfei Jia^2,*

CMC-Computers, Materials & Continua, Vol.82, No.3, pp. 4573-4591, 2025, DOI:10.32604/cmc.2025.059184 - 06 March 2025

Abstract In the context of security systems, adequate signal coverage is paramount for the communication between security personnel and the accurate positioning of personnel. Most studies focus on optimizing base station deployment under the assumption of static obstacles, aiming to maximize the perception coverage of wireless RF (Radio Frequency) signals and reduce positioning blind spots. However, in practical security systems, obstacles are subject to change, necessitating the consideration of base station deployment in dynamic environments. Nevertheless, research in this area still needs to be conducted. This paper proposes a Dynamic Indoor Environment Beacon Deployment Algorithm (DIE-BDA)… More >

Siham Hammid¹, Khatir Naima², Omolayo M. Ikumapayi³, Cheikh Kezrane¹, Abdelkrim Liazid⁴, Jihad Asad⁵, Mokdad Hayawi Rahman⁶, Farhan Lafta Rashid⁷, Naseer Ali Hussien⁸, Younes Menni^2,9,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 273-299, 2024, DOI:10.32604/cmes.2023.028951 - 22 September 2023

Abstract The objective of this investigation is to assess the effect of obstacles on numerical heat transfer and fluid flow momentum in a rectangular microchannel (MC). Two distinct configurations were studied: one without obstacles and the other with alternating obstacles placed on the upper and lower walls. The research utilized the thermal lattice Boltzmann method (LBM), which solves the energy and momentum equations of fluids with the BGK approximation, implemented in a Python coding environment. Temperature jump and slip velocity conditions were utilized in the simulation for the MC and extended to all obstacle boundaries. The… More >

Ameer Abed Jaddoa^* , Hussain Saad Abd

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-12, 2023, DOI:10.5098/hmt.20.6

Abstract In this work, the demeanour of heat transfer in a cooled upstanding turbulent flow condition of supercritical carbon dioxide SC- CO2 was investigated and analyzed. Several scenarios were adopted to handle the experimental data acquired by applying a perpendicular pipe with bending tape used in the examination model. The outcomes were presented using a typical method 'the dimensionless constitution'. Also, a modification was achieved to improve the relationship among the parameters for the processes of up and down flows. The achieved results will help address this research gap on turbulent perpendicular compound heat load based More >

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.20

Abstract This paper investigates numerically the problem of convective heat transfer and entropy generation by two adiabatic obstacles positioned inside a square cavity heated at the left wall and cooled on the right wall while horizontal walls are adiabatic. The inclination angle of the cavity orientation investigated are 30, 60 and 90 degrees. Rayleigh numbers ranging from 103 to 106 were calculated for two vertical obstacles. The method of Galerkin finite element was employed to solve the conservation equations of mass, momentum and energy. The cavity is assumed to be filled with air with Prandtl number More >

Raja Jarray¹, Mujahed Al-Dhaifallah^2,*, Hegazy Rezk^3,4, Soufiene Bouallègue^1,5

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 2159-2180, 2021, DOI:10.32604/cmc.2021.018752 - 21 July 2021

Abstract Paths planning of Unmanned Aerial Vehicles (UAVs) in a dynamic environment is considered a challenging task in autonomous flight control design. In this work, an efficient method based on a Multi-Objective Multi-Verse Optimization (MOMVO) algorithm is proposed and successfully applied to solve the path planning problem of quadrotors with moving obstacles. Such a path planning task is formulated as a multicriteria optimization problem under operational constraints. The proposed MOMVO-based planning approach aims to lead the drone to traverse the shortest path from the starting point and the target without collision with moving obstacles. The vehicle… More >

Huijin Park, Soobin Ou, Jongwoo Lee^*

Intelligent Automation & Soft Computing, Vol.29, No.1, pp. 247-258, 2021, DOI:10.32604/iasc.2021.015274 - 12 May 2021

Abstract Blind people are highly exposed to numerous dangers when they walk alone outside as they cannot obtain sufficient information about their surroundings. While proceeding along a crosswalk, acoustic signals are played, though such signals are often faulty or difficult to hear. The bollards can also be dangerous if they are not made with flexible materials or are located improperly. Therefore, since the blind cannot detect proper information about these obstacles while walking, their environment can prove to be dangerous. In this paper, we propose an object recognition system that allows the blind to walk safely… More >

Sooyeon Park¹, Moonseong Kim², Woochan Lee^{1, *}

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1181-1201, 2020, DOI:10.32604/cmc.2020.011245 - 20 August 2020

Abstract With the recent development of big data technology that collects and analyzes various data, the technology that continuously collects and analyzes the observed data is also drawing attention. Moreover, its importance is growing in data collection in areas where people cannot access. In general, it is not easy to properly deploy IoT wireless devices for data collection in these areas, and it is also inappropriate to use general wheelbased mobile devices for relocation. Recently, researches have been actively carried out on hopping moving models in place of wheel-based movement for the inaccessible regions. The majority… More >

Yali Wang¹, Youqian Feng¹, Zhonghai Yin¹, Cheng Zhou^{1, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 877-891, 2020, DOI:10.32604/cmc.2020.06423

Abstract This paper researches some problems in complex formation for multi-agents, in which two matrices are proposed to record the formation. The pattern matrix is used to describe the pattern of the formation; meanwhile, the location matrix is used to record the location of each agent. Thus, all desired positions of each agent will be obtained by geometrical relationship on the basis of two matrices above. In addition a self-adaptation flocking algorithm is proposed to control all agents to form a desired formation and avoid obstacles. The main idea is as follows: agents will form a More >

Tawfiq Chekifi^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.5, pp. 545-555, 2019, DOI:10.32604/fdmp.2019.01793

Abstract Numerical simulation using Ansys Fluent code is performed, to investigate droplet generation in cross-junction based VOF method. Droplets of water are generated by the shear stress applied by continuous phase (oil), two configurations of cross-junction are suggested; the first is a simple model no modification is performed at the outer channel, while the second model is characterized by a lateral obstacle. we study the effect of velocity ratio, viscous parameter, interfacial tension, flow condition on droplet size and frequency, the effect of lateral obstacles on droplets generation is also focused and analysed. The numerical simulations… More >