Ivan Shubenkov^1,2,*, Tatyana Lyubimova^1,2, Evgeny Sadilov¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 1957-1970, 2024, DOI:10.32604/fdmp.2024.050167 - 23 August 2024

Abstract In this paper, we study the onset and development of three-dimensional convection in a tilted porous layer saturated with a liquid. The layer is subjected to a gravitational field and a strictly vertical temperature gradient. Typically, problems of thermal convection in tilted porous media saturated with a liquid are studied by assuming constant different temperatures at the boundaries of the layer, which prevent these systems from supporting conductive (non-convective) states. The boundary conditions considered in the present work allow a conductive state and are representative of typical geological applications. In an earlier work, we carried… More > Graphic Abstract

Igor B. Palymskiy^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 957-974, 2024, DOI:10.32604/fdmp.2024.048829 - 07 June 2024

Abstract The fully nonlinear equations of gas dynamics are solved in the framework of a numerical approach in order to study the stability of the steady mode of Rayleigh-Bénard convection in compressible, viscous and heat-conducting gases encapsulated in containers with no-slip boundaries and isothermal top and bottom walls. An initial linear temperature profile is assumed. A map of the possible convective modes is presented assuming the height of the region and the value of the temperature gradient as influential parameters. For a relatively small height, isobaric convection is found to take place, which is taken over… More >

Hongzhi Liu¹, Shasha Wu¹, Yongjun Zhang^2,*, Tongxu Hu²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1551-1572, 2023, DOI:10.32604/fdmp.2023.024430 - 30 January 2023

Abstract The internal temperature of cast-in-place concrete bridges undergoes strong variations during the construction as a result of environmental factors. In order to determine precisely such variations, the present study relies on the finite element method, used to model the bridge box girder section and simulate the internal temperature distribution during construction. The numerical results display good agreement with measured temperature values. It is shown that when the external temperature is higher, and the internal and external temperature difference is relatively small, the deviation of the fitting line from existing specifications (Chinese specification, American specification, New More >

Qi Wu^*, Jianan Li, Lianchun Long, Linao Liu

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.1, pp. 99-116, 2021, DOI:10.32604/cmes.2021.015669 - 24 August 2021

Abstract During heat treatment or mechanical processing, most polycrystalline materials experience grain growth, which significantly affects their mechanical properties. Microstructure simulation on a mesoscopic scale is an important way of studying grain growth. A key research focus of this type of method has long been how to efficiently and accurately simulate the grain growth caused by a non-uniform temperature field with temperature gradients. In this work, we propose an improved 3D Monte Carlo Potts (MCP) method to quantitatively study the relationship between non-uniform temperature fields and final grain morphologies. Properties of the aluminum alloy AA6061-T6 are… More >

Hashem Shatnawi^1,2,*, Chin Wai Lim², Firas Basim Ismail³, Abdulrahman Aldossary¹

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 1693-1711, 2021, DOI:10.32604/cmc.2021.016741 - 13 April 2021

Abstract The receiver is an important element in solar energy plants. The principal receiver’s tubes in power plants are devised to work under extremely severe conditions, including excessive heat fluxes. Half of the tube’s circumference is heated whilst the other half is insulated. This study aims to improve the heat transfer process and reinforce the tubes’ structure by designing a new receiver; by including longitudinal fins of triangular, circular and square shapes. The research is conducted experimentally using Reynolds numbers ranging from 28,000 to 78,000. Triangular fins have demonstrated the best improvement for heat transfer. For More >

K.S. Balamurugan^a,*, N. Udaya Bhaskara Varma^b, J.L. Ramaprasad^c

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-7, 2020, DOI:10.5098/hmt.15.8

Abstract In this paper the entropy generation and temperature gradient heat source effects on MHD couette flow with permeable base in the presence of thermal radiation, viscous and joule's dissipation is studied. An exact solution of governing equations has been attained in closed form. The influences of several parameters on the velocity and temperature profiles and entropy generation are analyzed through graphs. Bejan number for different values have been calculated and displayed pictorially. The skin friction coefficient and Nusselt number at channel walls are derived and discussed their behaviour through tables. The entropy generation increases with More >

S. Palaniammal¹ , K. Saritha^2,*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-10, 2018, DOI:10.5098/hmt.10.1

Abstract This paper investigates heat and mass transfer of a MHD Casson fluid over a permeable stretching surface in the presence of a temperature gradient heat sink. The effects of viscous dissipation, thermal radiation and chemical reaction are also taken into the consideration. The relevant similarity transformations are used to reduce the governing equations into a system of nonlinear ordinary differential equations and then solved analytically. The influence of various physical parameters on the velocity, temperature, concentration, skin friction coefficient, Nusselt and Sherwood numbers are investigated. The numerical results of skin friction factor, Nusselt and Sherwood More >

Bingfei Liu¹, Guansuo Dui^2,3, Lijun Xue², Benming Xie¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.3, pp. 239-260, 2013, DOI:10.32604/cmes.2013.094.239

Abstract Analytical solutions are derived for the macroscopic behaviors of a Shape Memory Alloy (SMA) thick-walled cylinder subjected to internal pressure and radial temperature gradient. The Tresca transformation criterion and linear hardening are used. Equations are given for the radial and circumferential stresses, transformation strains and martensite volume fractions at both the elastic step and the transformation step. Numerical results are presented and in good agreement with the finite element simulations. More >

Brahim Mahfoud¹, Rachid Bessaih^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 1-26, 2012, DOI:10.3970/fdmp.2011.008.001

Abstract Oscillatory swirling flows in a cylindrical enclosure, having aspect ratio (height/radius) γ=2, filled with a liquid metal, and submitted to a destabilizing vertical temperature gradient (system heated from below) is investigated by means of direct numerical solution of the governing (continuity, radial and axial momentum,swirlandenergy)equations. The bottom and top disks are assumed to rotate at equal (co-rotating) and opposite (counter-rotating) angular velocities. The critical Reynoldsnumber,Re_cr and the critical frequency of oscillations, F_cr arecalculated as a function of the Richardson number, Ri, ranging between 0 and 4. Stability diagrams are presented, reflecting the results of the numerical More >

Dong Wei¹, Yinghua Liu^1,2, Zhihai Xiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.1, pp. 77-106, 2009, DOI:10.3970/cmes.2009.046.077

Abstract Taking advantage of the parameter identification, a new numerical method is developed in this paper to estimate the maximal temperature gradients reached in fire-damaged concrete structures. This method can avoid the hypotheses of temperature-time curve and fire duration usually made in conventional numerical methods, availably evaluate the depth and degree of fire damage of concrete structures and consider the effects of localized fire. A material model taking into account the properties of fire-damaged concrete is firstly proposed in the present research. The least-squares estimation and the Gauss-Newton method are used to identify the material parameters… More >