Xi Wang¹, Shan Qing^1,*, Zhumei Luo^1,*, Yiqin Liu^1,2, Zichang Shi¹, Jiachen Li¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2399-2416, 2023, DOI:10.32604/fdmp.2023.028024

Abstract Propylene glycol-based MWCNT (multi-walled carbon nanotubes) nanofluids were prepared in the framework of a two-step method and by using a suitable PVP (polyvinyl pyrrolidone) dispersant. The BBD (Box-Behnken design) model was exploited to analyze 17 sets of experiments and examine the sensitivity of the absorbance to three parameters, namely the concentration of MWCNT, the SN ratio (mass ratio of carbon nanotubes to surfactants) and the sonication time. The results have revealed that, while the SN ratio and concentration of MWCNT have a strong effect on the absorbance, the influence of the sonication time is less important. The statistical method of… More >

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

Frontiers in Heat and Mass Transfer, Vol.16, No.1, 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 up to (45o),… More >

M. Y. Dhange^a,*, G. C. Sankad^a, Ishwar Maharudrappa^b

Frontiers in Heat and Mass Transfer, Vol.18, No.1, pp. 1-6, 2022, DOI:10.5098/hmt.18.36

Abstract The present paper investigates the impacts of heat transfer and magnetic field on the boundary layer flow of Casson fluid over a linearly stretching sheet. The researchers have introduced analytical and numerical solutions for the momentum and energy equations by transforming the equations into the system of ordinary differential equations with the aid of the similarity transformations technique. The velocity and temperature profiles for pertinent constraints like Casson fluid constraint, Chandrasekhar number, Prandtl number, and thermal conductivity are presented through graphs. The influence of the wall shear stress and the Prandtl number increases while the boundary layer thickness decreases. Further,… More >

Jiachen Li^1,2, Wenlong Deng³, Shan Qing^1,2,*, Yiqin Liu⁴, Hao Zhang^1,2, Min Zheng^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2181-2200, 2023, DOI:10.32604/fdmp.2023.027299

Abstract In this study, comparing multiple models of machine learning, a multiple linear regression (MLP), multilayer feed-forward artificial neural network (BP) model, and a radial-basis feed-forward artificial neural network (RBF-BP) model are selected for the optimization of the thermal properties of TiO₂/water nanofluids. In particular, the least squares support vector machine (LS-SVM) method and radial basis support vector machine (RB-SVM) method are implemented. First, curve fitting is performed by means of multiple linear regression in order to obtain bivariate correlation functions for thermal conductivity and viscosity of the nanofluid. Then the aforementioned models are used for a predictive analysis of the… More >

A. Lkouen^1,*, M. Lamrani², A. Meskini¹, A. Khabbazi³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2013-2026, 2023, DOI:10.32604/fdmp.2023.026929

Abstract Most of the energy savings in the building sector come from the choice of the materials used and their microphysical properties. In the present study, through numerical simulations a link is established between the thermal performance of composite materials and their microstructures. First, a two-phase 3D composite structure is modeled, then the RSA (Random Sequential Addition) algorithm and a finite element method (FE) are applied to evaluate the effective thermal conductivity of these composites in the steady-state. In particular, building composites based on gypsum and clay, consolidated with peanut shell additives and/or cork are considered. The numerically determined thermal conductivities… More > Graphic Abstract

Soumaya Zormati, Fadhel Aloulou^*, Habib Sammouda

Journal of Renewable Materials, Vol.11, No.5, pp. 2345-2365, 2023, DOI:10.32604/jrm.2023.026170

Abstract

The objective of this study is to analyze the effects of using surfactant (CTAB) and cellulose nanofibers (NFC) as an admixture in cement mortars. We examined composite properties as porosity, compression energy, thermal conductivity and hydration. The results showed that with the addition of 0.7% by weight of NFC per emulsion in the presence of a cationic surfactant (CTAB). The new material produced presented a dry porosity between 4.7% and 4.4%, compressive strength between 9.8 and 22.9 MPa, and thermal conductivity between 0.95 and 2.25 W·m⁻¹·K⁻¹. Thus we show better mechanical and thermal performance than that traditional Portland cement mortar… More > Graphic Abstract

Yiwen Zhang¹, Jianjun Xie^1,*, Minghui Sun¹, Shaolong Wang¹, Tengfei Xu^2,3, Yonggen Xu^2,3, Xiaoqing Ding^2,3, Ying Shi¹, Lei Zhang¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2125-2141, 2023, DOI:10.32604/jrm.2023.025127

Abstract Foam glass is a kind of green building material that is widely used because of its excellent thermal insulation and mechanical properties. In this study, the borosilicate foam glass was fabricated by powder sintering method using recycled soda lime waste glass, quartz, and borax as the primary raw materials. CaCO₃ was used as a foaming agent and Na₂CO₃ as a flux agent. Results showed that as the quartz content decreases from 30 to 17.5 wt.% and borax content increases from 5 to 17.5 wt.%, the pore size, porosity, and thermal insulation of borosilicate foam glass increase significantly, while the compressive strength decreases… More > Graphic Abstract

Hamadou-Ali Mohamed^1,*, Benazzouk Amar^1,*, Haïkel Ben Hamed¹, Arash Jamali²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 723-741, 2023, DOI:10.32604/fdmp.2022.021841

Abstract The feasibility of a sustainable non-autoclaved cellular concrete, based on flax vegetable co-products, for the production of usable specimen in the lightweight construction field, has been investigated experimentally. The produced specimen, containing various volume ratios of flax particles with respect to preformulatd Tradical PF70 lime binder of 0, 1, and 2, were lightened by creating a porous structure in the matrix through the addition of 0.3% wt. Aluminium powder (able to react with calcium hydroxide from the binder and result in microscopic air-bubbles). Fresh and hardened specimen properties, including hydration, fresh density, porosity, hardened density, compressive and flexural strengths, toughness… More >

Yue Yu^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 697-709, 2023, DOI:10.32604/fdmp.2022.021482

Abstract The sol-gel method is used to prepare a new nano-alumina aerogel structure and the thermal properties of this nanomaterial are investigated comprehensively using electron microscope scanning, thermal analysis, X-ray and infrared spectrometer analysis methods. It is found that the composite aerogel alumina material has a multi-level porous nano-network structure. When employed for the thermal insulation of high-rise buildings, the alumina nanocomposite aerogel material can lead to effective energy savings in winter. However, it has almost no energy-saving effect on buildings where energy is consumed for cooling in summer. More >

Bin Lin¹, Zhengyu Li^2,*, Dong Wen², Jianchao Liu², Shan Yang³, Yong Zhou², Chao Lu⁴, Qian Qiu^4,5

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 1509-1521, 2023, DOI:10.32604/cmc.2023.032557

Abstract The further development of catalytic elements has been plagued by activation and binary problems. The automatic shift model that has emerged in recent years helps components achieve full range. However, the detection data still remains unstable in the shift area (7%~13%). This paper proposes a Catalytic Combustion and Thermal Conductivity (CCTC) model for the specified range, which can be explained from two aspects based on the existing methods. On the one hand, it uses iterative location search to process heterogeneous data, judges the prediction position of data points, and then gives weight evaluation. On the other hand, it corrects the… More >