Yongtong Li¹, Liang Gong^{1, *}, Hui Lu¹, Dexin Zhang¹, Bin Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 895-912, 2020, DOI:10.32604/cmes.2020.09009 - 01 May 2020

Abstract In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers… More >

Lionel Fabian Fourie¹, Lynndle Square^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 225-235, 2020, DOI:10.32604/fdmp.2020.08771 - 21 April 2020

Abstract A heat transfer study was conducted, in the framework of Computational Fluid Dynamics (CFD), on a Hot-Wire Chemical Vapour Deposition (HWCVD) reactor chamber to determine a safe deposition distance for atomic hydrogen produced by HWCVD. The objective of this study was to show the feasibility of using heat transfer simulations in determining a safe deposition distance for deposition of this kind. All CFD simulations were set-up and solved within the framework of the CFD packages of OpenFOAM namely; snappyHexMesh for mesh generation, buoyantSimpleFoam and rhoSimpleFoam as the solvers and paraView as the post-processing tool. Using More >

Yufeng Ma¹, Xuanang Gong¹, Puyou Jia^2,*

Journal of Renewable Materials, Vol.8, No.1, pp. 45-55, 2020, DOI:10.32604/jrm.2020.08621 - 01 January 2020

Abstract In order to improve the comprehensive performance of phenolic foam, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was grafted with itaconic acid (ITA) (DOPO-g-ITA) to modify microcrystalline cellulose (MCC). DOPO-g-ITA modified MCC (DIMMCC) was used to prepare composite phenolic foam (DCPF). The structures of DIMMCC were verified by Fourier transform infrared spectroscopy (FT-IR). The microstructure and crystalline property were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. Compared with MCC, the crystallinity of DIMMCC was dramatically decreased, but the diffraction peak positions were unchanged. Thermal stability was decreased, and T_i decreased by 45.0°C. The residual carbon (600°C) More >

Roohalah Hajizadeh¹, Ali Khavanin^2,*, Mohammad Barmar³, Ahmad Jonidi Jafari⁴, Somayeh Farhang Dehghan⁵

Sound & Vibration, Vol.53, No.5, pp. 207-222, 2019, DOI:10.32604/sv.2019.06523

Abstract Polyurethane foam as the most well-known absorbent materials has a suitable absorption coefficient only within a limited frequency range. The aim of this study was to improve the sound absorption coefficient of flexible polyurethane (PU) foam within the range of various frequencies using clay nanoparticles, polyacrylonitrile nanofibers, and polyvinylidene fluoride nanofibers. The response surface method was used to determine the effect of addition of nanofi- bers of PAN and PVDF, addition of clay nanoparticles, absorbent thickness, and air gap on the sound absorption coefficient of flexible polyurethane foam (PU) across different frequency ranges. The absorption… More >

Zehui Ju¹, Qian He¹, Tianyi Zhan¹, Haiyang Zhang^1,*, Lin Sun¹, Lu Hong¹, Xinyi Shi², Xiaoning Lu^1,*

Journal of Renewable Materials, Vol.7, No.11, pp. 1077-1091, 2019, DOI:10.32604/jrm.2019.07525 - 14 July 2021

Abstract In this study, steam exploded peanut shell fibers (SE-PSFs) were utilized to fabricate with rigid polyurethane foam (RPUF) in order to improve sound absorption performance and hydrothermal weather resistance. Optimized method of SE treatment, RPUF preparation and flame retardant treatment were selected to prepare SE-PSF/RPUF composites in this experiment. Physical and mechanical properties including density, water absorption capacity, thickness swelling rate, compressive strength, thermal conductivity and average sound absorption coefficient of SE-PSF/RPUF were investigated and compared with the control (PRUF). The results showed that the density, water absorption capacity, thickness swelling rate and thermal conductivity More >

Shangmin Ao, Peng Wang*, Lin Zhang, Yajun Deng, Dongliang Sun*, Bo Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 152-153, 2019, DOI:10.32604/icces.2019.05005

Abstract The problem of fluid flow and heat transfer in porous media is one common phenomenon in industrial production and daily life. Numerical simulation for the above problem can provide a realistic understanding of transport processes and thus can help to optimize energy consumption. However, in the macroscopic model of fluid flow and heat transfer, the convergence rate of traditional numerical methods is usually poor as the hygroscopic properties of porous media. Therefore, it is of great significance to develop an efficient algorithm for the macroscopic model of fluid flow and heat transfer in porous media.… More >

Yufeng Ma¹, Xuanang Gong¹, Bing Xie¹, Xiang Geng¹, Puyou Jia^2,*

Journal of Renewable Materials, Vol.7, No.10, pp. 1037-1046, 2019, DOI:10.32604/jrm.2019.07454

Abstract In order to improve the mechanical properties without reducing its flame retardancy of phenolic foams (PFs), 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was introduced in the structure of cashew nut shell liquid (CNSL) to improve its flame retardant, and the product of DOPO grafting CNSL (DOPO-g-CNSL) was obtained to modify phenolic resin, and to prepare DOPO-g-CNSL modified PFs (DCMPFs). The structures of DOPO-g-CNSL were verified by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H-NMR). Compared with CNSL, thermal stability of DOPO-g-CNSL was decreased and Ti decreased by 3.53%, but the residual carbon (800°C) was increased by More >

Fei Song¹, Puyou Jia^1,*, Yanan Xiao², Caiying Bo¹, Lihong Hu¹, Yonghong Zhou^1,*

Journal of Renewable Materials, Vol.7, No.10, pp. 1011-1021, 2019, DOI:10.32604/jrm.2019.08044

Abstract Phenolic foams (PFs) as thermal insulation material with outstanding flame retardancy are required to match society’s ever expanding safety expectations; however, a trade off exists between flame retardancy and toughness. Here, for the first time, we synthesized a novel reactive phosphorus containing tung oil based derivative and used it to toughen PF, resulting in PFs with a combination of excellent mechanical properties and flame retardancy. Compared with pure PF, the modified PFs exhibit enhanced mechanical properties, with specific compressive and flexural strengths as high as 5.67 MPa and 12.46 MPa, which represent increases of 90.67% More >

Antonio Pizzi*

Journal of Renewable Materials, Vol.7, No.5, pp. 477-492, 2019, DOI:10.32604/jrm.2019.06511

Abstract This review details the development of tannin-based biofoams for fire resistance and acoustic insulation and details the different varieties of these foams that have been developed, from tannin-furanic self-blowing foams to tannin-furanic polyurethanes and finally non-isocyanate tannin-based-carbohydrates polyurethanes (NIPU). More >

Xuedong Xi^1,2, A. Pizzi^1,*, C. Gerardin³, Guanben Du²

Journal of Renewable Materials, Vol.7, No.3, pp. 301-312, 2019, DOI:10.32604/jrm.2019.04174 - 14 July 2021

Abstract Glucose-based non-isocyanate polyurethanes (NIPU) were prepared by reaction of glucose with dimethyl carbonate and hexamethylene diamine. These were used to prepare partially biobased polyurethane foams by reaction with NaHCO3 as a blowing agent and addition of a silane coupling agent having different functions such as coreactant and adjuvant to obtain more uniform and smaller cells. The foams were foamed and hardened by applying heat. The foams presented very limited fire resistance indicating that as for synthetic polyurethane foams the eventual use of a fire retardant appears to be necessary. The 2 hours water absorption was More >