Nikola Vavřínová^*, Kateřina Stejskalová, Jiří Teslík, Kateřina Kubenková, Jiří Majer

Journal of Renewable Materials, Vol.10, No.7, pp. 1859-1873, 2022, DOI:10.32604/jrm.2022.018908

Abstract This article is focused on the investigation of the mechanical and thermal properties of composite material that could be used for the production of plaster or plasterboards. This composite material is made of gypsum and reinforcing natural fibers. The article verifies whether this natural reinforcement can improve the investigated properties compared to conventional plasters and gypsum plasterboards made of pure gypsum. From this composite material, high-strength plasterboards could then be produced, which meet the higher demands of users than conventional gypsum plasterboards. For their production, natural waste materials would be used efficiently. As part of… More >

Dadang Mohamad^1,*, Mohammed Abed Jawad², John William Grimaldo Guerrero³, Tonton Taufik Rachman⁴, Huynh Tan Hoi⁵, Albert Kh. Shaikhlislamov⁶, Mustafa M. Kadhim⁷, Saif Yaseen Hasan⁸, A. Surendar⁹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 851-866, 2022, DOI:10.32604/fdmp.2022.019485

Abstract

Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters, namely, on the thermal conductivity and viscosity of aqueous salt solutions at temperatures of 293–473 K, pressures Ps = 100 MPa, and concentrations of 0–25 wt.%. Given the lack of data and models, especially for the dynamic viscosity of aqueous salt solutions at a pressure of above 40 MPa, generalized formulas are presented here, by which these gaps can be filled. The article presents a generalized formula for obtaining reliable data on the thermal conductivity of water

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Yuling Zhai^*, Long Li, Zihao Xuan, Mingyan Ma, Hua Wang

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 629-646, 2022, DOI:10.32604/fdmp.2022.017485

Abstract The thermo-physical properties of nanofluids are highly dependent on the used base fluid. This study explores the influence of the mixing ratio on the thermal conductivity and viscosity of ZnO-CuO/EG (ethylene glycol)-W (water) hybrid nanofluids with mass concentration and temperatures in the ranges 1-5 wt.% and 25-60°C, respectively. The characteristics and stability of these mixtures were estimated by TEM (transmission electron microscopy), visual observation, and absorbance tests. The results show that 120 min of sonication and the addition of PVP (polyvinyl pyrrolidone) surfactant can prevent sedimentation for a period reaching up to 20 days. The… More >

Bing Liu¹, Yikun Chen¹, Huachen Liu¹, Qiao Wu¹, Minghui Wang¹, Jianlong Wan^2,*

Energy Engineering, Vol.119, No.2, pp. 815-826, 2022, DOI:10.32604/ee.2022.017988

Abstract The operating range of the flow rate or flow velocity for the micro-jet flame is quite wide, which can be used as the heat source. In order to optimize the micro-jet tube combustor in terms of the solid material, the present paper numerically investigates the impact of thermal conductivity (λ_s) on the operating limit of micro-jet flame. Unexpectedly, the non-monotonic blow-off limits with the increase of λ_s is found, and the corresponding generation mechanisms are analyzed in terms of the thermal coupling effect, flow field, and strain effect. At first, the lower preheating temperature of the More >

Kang Liu, Yanqiao Wang^*

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.1, pp. 119-135, 2022, DOI:10.32604/cmes.2022.018134

Abstract Soil slope stability in seasonally frozen regions is a challenging problem for geotechnical engineers. The freeze-thaw process of soil slope caused by the temperature fluctuation increases the difficulty in predicting the slope stability because the soil property is influenced by the freeze-thaw cycle. In addition, the frozen soil, which has ice crystal, ice lens and experienced freeze-thaw process, could present stronger heterogeneity. Previous research has not investigated the combined effect of soil heterogeneity and freeze-thaw cycle. This paper studies the influence of soil heterogeneity on the stability of frozen soil slope under freeze-thaw cycles. The… More >

Muhammad Sami Rashad¹, Haihu Liu^1,*, Shan Ali Khan²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 233-254, 2022, DOI:10.32604/cmes.2022.017277

Abstract A mathematical modeling is explored to scrutinize the unsteady stagnation point flow of Oldroyd-B nanofluid under the thermal conductivity and solutal diffusivity with bioconvection mechanism. Impacts of Joule heating and Arrhenius activation energy including convective boundary conditions are studied, and the specified surface temperature and constant temperature of wall (CTW) are discussed. The consequences of thermal conductivity and diffusivity are also taken into account. The flow is generated through stretchable disk geometry, and the behavior of non-linear thermal radiation is incorporated in energy equation. The partial differential equations governing the fluid flow in the structure… More >

Kafel Azeez Mohammed^a,*, Ahmed Mustaffa Saleem^b , Zain alabdeen H. Obaid^a

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-8, 2021, DOI:10.5098/hmt.16.20

Abstract Numerical investigation is performed for the determination of Nusselt number of ZnO, TiO₂ and SiO₂ nanoparticles dispersed in 60% ethylene glycol and 40% water inside inclined cylinder for adiabatic and isothermal process. The present study was conducted for both the constant heat flux (10,000 W/m²) and constant wall temperature (313.15 K) boundary conditions. At the inlet, the uniform axial velocity and initial temperature (293 K) were assumed. The results show the change of average Nusselt number at Reynolds number (400), Rayleigh number (10⁶) and volume fraction percentage (2%). From results for adiabatic process when increasing the slop More >

F. S. Bayones¹, S. M. Abo-Dahab^2,*, Ahmed E. Abouelregal³, A. Al-Mullise¹, S. Abdel-Khalek^1,4, E. M. Khalil^1,5

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 2899-2913, 2021, DOI:10.32604/cmc.2021.012583

Abstract The present paper paper, we estimate the theory of thermoelasticity a thin slim strip under the variable thermal conductivity in the fractional-order form is solved. Thermal stress theory considering the equation of heat conduction based on the time-fractional derivative of Caputo of order α is applied to obtain a solution. We assumed that the strip surface is to be free from traction and impacted by a thermal shock. The transform of Laplace (LT) and numerical inversion techniques of Laplace were considered for solving the governing basic equations. The inverse of the LT was applied in More >

Zhiqiang Shu, Jianmin Wu^*, Shaoqing Li, Bingbing Zhang, Jianqi Yang

Journal of Renewable Materials, Vol.9, No.2, pp. 365-380, 2021, DOI:10.32604/jrm.2021.014379

Abstract The use of steel slag, which is a by-product of the steel manufacture, in the construction of asphalt pavement would contribute to waste reduction and environment protection. Using rubber asphalt at the same time can improve the performance of asphalt mixture. This study investigates the influence of steel slag content on the road performance, thermal conductivity and outdoor temperature distribution of steel slag rubber asphalt mixtures (SSRAM), and calculates the cumulative stress in surface layer. At a certain range of concentration, the steel slag additive improved the deformation resistance and low-temperature cracking resistance of the… More >

Ali Rehman^a , Zabidin Salleh^a,* , Taza Gul^b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-7, 2020, DOI:10.5098/hmt.14.20

Abstract This research paper explains the analytical solution unsteady squeezing flow of water based CNTs for both MWCNT and SWCNT in the presence of magnetic field and variable thermal conductivity. The given partial differential equation is converted to nonlinear ordinary differential equation by using the similarity transformation and solve by analytical method namely optimal homotopy asymptotic method (OHAM) to obtain analytical solution of the nonlinear problem which analyze the problem. The result of important parameter for both velocity and temperature profiles are plotted and discussed. The BVPh 2.0 package is used to obtain the convergence of More >