Harumi Toriyama^*, Yutaka Asako

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-6, 2010, DOI:10.5098/hmt.v1.1.3005

Abstract Effects of a magnetic field on aeration through porous medium compost have been investigated numerically. Some composts yield heat over 60 degrees Celsius in fermentation process. That exothermic reaction produces a considerable amount of heat, which could be a potential heating source. Fermentation reaction requires aeration, sufficient supply of paramagnetic oxygen gas and exhaust of metabolized diamagnetic carbon dioxide gas. Continuous and forced air supply is more efficient rather than conventional manual turns or stirrings as aeration means. In magnetoaero-dynamics, the magnetizing force acting on a paramagnetic oxygen gas is applied for the enhancement of airflow, heat and mass transfer.… More >

Junzhe Cui¹, Dechun Zhang¹, Peng Li^1,*, Yiren Yang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.010401

Abstract This study investigates the static instability of a cracked plate in subsonic airflow. The plate model is an inverted cantilever plate, where its leading edge is free and the trailing edge the clamped. A mathematical model of the crack is developed using the Dirac function, while Theodorsen aerodynamic mode is applied for the fluid force. To account for angle discontinuity caused by cracks, Fourier expansion is employed to transform the form corresponding to the angle into a continuous model. The critical divergent dynamic pressure and mode of an inverted cantilever plate with a crack are calculated using the Galerkin method.… More >

Xinzong Wang¹, Xiaofang Kang^1,2,*, Qingguan Lei¹

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1749-1771, 2023, DOI:10.32604/cmes.2023.027745

Abstract The chaotic motion behavior of the rectangular conductive thin plate that is simply supported on four sides by airflow and mechanical external excitation in a magnetic field is studied. According to Kirchhoff ’s thin plate theory, considering geometric nonlinearity and using the principle of virtual work, the nonlinear motion partial differential equation of the rectangular conductive thin plate is deduced. Using the separate variable method and Galerkin’s method, the system motion partial differential equation is converted into the general equation of the Duffing equation; the Hamilton system is introduced, and the Melnikov function is used to analyze the Hamilton system,… More > Graphic Abstract

Changming Ling^a,b,*, Yin Zhong^a,b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-6, 2020, DOI:10.5098/hmt.14.25

Abstract Effects of serrated pulsating airflow on liquid film evaporation in a falling film channel was numerically studied based on a two-dimensional model. The mechanism of pulsating airflow evaporation was studied as the pulsating airflow swept across the vertical liquid film surface at the stagnant temperature. Effects of amplitude, frequency, and velocity of the serrated pulsating airflow at certain evaporation time on evaporation were analyzed. Compared with the uniform airflow, the highest relative evaporation of liquid film on vertical pipe inner surface was increased by about 0.3 %. When the airflow was pulsating, the cycle of vapor mass flow rate was… 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 >

Abid. A. Memon¹, M. Asif Memon¹, Kaleemullah Bhatti¹, Thanin Sitthiwirattham^2,*, Nichaphat Patanarapeelert³

CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 4835-4853, 2022, DOI:10.32604/cmc.2022.023912

Abstract For heat transfer enhancement in heat exchangers, different types of channels are often tested. The performance of heat exchangers can be made better by considering geometry composed of sinusoidally curved walls. This research studies the modeling and simulation of airflow through a units long sinusoidally curved wavy channel. For the purpose, two-dimensional Navier Stokes equations along with heat equations are under consideration. To simulate the fluid flow problem, the finite element-based software COMSOL Multiphysics is used. The parametric study for Reynolds number from to and the period of vibration P from to are observed. The surface plots, streamline patterns, contours,… More >

Xiaosai Duan, Suihuai Yu^*, Jianjie Chu, Dengkai Chen and Zhaojing Su

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 701-721, 2022, DOI:10.32604/cmes.2022.016779

Abstract The rational design of airflow distribution is of great importance for comfort and energy conservation. Several numerical investigations of flow and temperature characteristics in cockpits have been performed to study the distinct airflow distribution. This study developed the coupled heat transfer model of radiation, convection, and heat conduction for the cockpit flight environment. A three-dimensional physical model was created and a shear stress transfer (SST) k-w turbulence model was well verified with a high prediction accuracy of 91% for the experimental data. The strong inhomogeneous flow and temperature distribution were captured for various initial operating conditions (inlet temperature, inlet pressure,… More >

W. M. Faizal^1,2, N. N. N. Ghazali^2,*, C. Y. Khor¹, M. Z. Zainon², Irfan Anjum Badruddin^3,4,*, Sarfaraz Kamangar⁴, Norliza Binti Ibrahim⁵, Roziana Mohd Razi⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.2, pp. 583-604, 2021, DOI:10.32604/cmes.2021.015549

Abstract Background: Obstructive sleep apnea is a sleeping disorder that has troubled a sizeable population. There is an active area of research on obstructive sleep apnea that intends to better understand airflow behaviors and therefore treat patients more effectively. This paper aims to investigate the airflow characteristics of the upper airway in an obstructive sleep apnea (OSA) patient under light and heavy breathing conditions by using Turbulent Kinetic Energy (TKE), an accurate method in expressing the flow concentration mechanisms of sleeping disorders. It is important to visualize the concentration of flow in the upper airway in order to identify the severity… More >

Yunfei Liao^1,*, Jin Liu²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 961-977, 2020, DOI:10.32604/fdmp.2020.09163

Abstract In order to improve the convective heat transfer relating to an eddy current retarder, the finite element model has been used to assess the performances of different possible designs. In particular, assuming the steady running state of retarder as the working condition, flow and temperature fields have been obtained for the rotor. The influence of airflow path on heat dissipation has been analysed, and the influence of the temperature field distribution on the performance of retarder has been discussed accordingly. The results show that when the steady running state of the turntable is considered, the maximum temperature is lower, the… More >

Mingge Wu¹, Lei Wang¹, Yixiang Wang¹, Cheng Zhang¹, Cheng Qiu^{1, 2, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 431-444, 2019, DOI:10.32604/fdmp.2019.08209

Abstract Water management in proton exchange membrane fuel cells (PEMFC) is a topic of great importance for the optimization of these systems. Effective proton conductivity calls for moderate moisture content in the membrane, while uneven water distribution can lead to instability of the whole flow field, thereby decreasing the performance of the fuel cell. In the present study, a simplified two-tier hybrid structure is used to investigate the impact of the dynamic behavior of liquid water on the current density of the PEMFC. Simulation results show that water droplets attached to wall sides tend to increase current density. Visualization experiments confirm… More >