Zhiqiang Wang¹, Xuede Wang¹, Xin Zhou^1,*, Guangzhao Ye², Xing Cheng^1,3, Peiyu Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 243-263, 2020, DOI:10.32604/cmes.2020.09934

Abstract During the selective laser melting process, a high-energy laser beam acts on the powder, a molten pool is rapidly generated and the characteristic parameters are constantly changing. Among them, temperature is one of the important parameters in the forming process. Due to the generation of splash particles, there will be defects in the microstructure, which will seriously affect the formation quality of the prepared parts. Therefore, it is necessary to study the relationships between the splash behavior, molten pool characteristics and product quality. The finite element simulation of the transient temperature field was performed by ANSYS software. Time-series images at… More >

Di Wang¹, Guangzhao Ye¹, Jingming Mai², Xiaomin Chen¹, Yongqiang Yang^1,*, Yang Li^1,*, Xiaojun Chen¹, Jie Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1061-1077, 2020, DOI:10.32604/cmes.2020.09842

Abstract In this paper, a novel micromixer with complex 3D-shape inner units was put forward and fabricated by metal Additive Manufacturing (AM). The design of the micromixer combined the constraints of selective laser melting technology and the factors to improve mixing efficiency. Villermaux-Dushman reaction system and Compute Fluid Design (CFD) simulation were conducted to investigate the performance and the mechanism of this novel micromixer to improve mixing efficiency. The research found that the best mixing efficiency of this novel micromixer could be gained when the inner units divided fluid into five pieces with a uniform volume. Compared with a conventional micromixer… More >

Xinglong Wang^1,2, Cheng Wang^1,2, Xin Zhou^1,*, Mingkang Zhang³, Peiyu Zhang¹, Lei Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 495-508, 2020, DOI:10.32604/cmes.2020.09778

Abstract The new regenerative cooling thermal protection system exhibits the multifunctional characteristics of load-carrying and heat exchange cooling, which are fundamental for the lightweight design and thermal protection of hypersonic vehicles. Triply periodic minimal surface (TPMS) is especially suitable for the structural design of the internal cavity of regenerative cooling structures owing to its excellent structural characteristics. In this study, test pieces were manufactured using Ti6Al4V lightweight material. We designed three types of porous test pieces, and the interior was filled with a TPMS lattice (Gyroid, Primitive, I-WP) with a porosity of 30%. All porous test pieces were manufactured via selective… More >

K. Ganesh Kumar^{1, *}, S. Manjunatha², N. G. Rudraswamy³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 131-146, 2020, DOI:10.32604/fdmp.2020.0152

Abstract Boundary layer flows and melting heat transfer of a Prandtl fluid over a stretching surface in the presence of fluid particle suspensions has been investigated. The converted set of boundary layer equations are solved numerically by RKF-45 method. Obtained numerical results for flow and heat transfer characteristics are deliberated for various physical parameters. Furthermore, the skin friction coefficient and Nusselt number are also presented in Tabs. 2 and 3. It is found that the heat transfer rates are advanced in occurrence of nonlinear radiation compered to linear radiation. Also, it is noticed that velocity and temperature profile increases by increasing… More >

Rubén Avila¹, Eduardo Ramos², S. N. Atluri³

CMES-Computer Modeling in Engineering & Sciences, Vol.51, No.1, pp. 73-92, 2009, DOI:10.3970/cmes.2009.051.073

Abstract A Chebyshev Tau numerical algorithm is presented to solve the perturbation equations that result from the linear stability analysis of the convective motion of a fluid layer that appears when an unconfined solid melts in the presence of gravity. The system of equations that describe the phenomenon constitute an eigenvalue problem whose accurate solution requires a robust method. We solve the equations with our method and briefly describe examples of the results. In the limit where the liquid-solid interface recedes at zero velocity the Rayleigh-Bénard solution is recovered. We show that the critical Rayleigh number Ra_c and the critical wave… More >

G. Kosec¹, B. Šarler²

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.2, pp. 191-216, 2009, DOI:10.3970/cmes.2009.047.191

Abstract This paper explores an application of a novel mesh-free Local Radial Basis Function Collocation Method (LRBFCM) [Sarler and Vertnik (2006)] in solution of coupled heat transfer and fluid flow problems with solid-liquid phase change. The melting/freezing of a pure substance is solved in primitive variables on a fixed grid with convection suppression, proportional to the amount of the solid fraction. The involved temperature, velocity and pressure fields are represented on overlapping sub-domains through collocation by using multiquadrics Radial Basis Functions (RBF). The involved first and second derivatives of the fields are calculated from the respective derivatives of the RBF's. The… More >

R. Avila¹, F.J. Solorio¹

CMES-Computer Modeling in Engineering & Sciences, Vol.44, No.2, pp. 177-202, 2009, DOI:10.3970/cmes.2009.044.177

Abstract Heat transfer processes involving phase change either, solidification or melting, appear frequently in nature and in industrial applications. In this paper the convective patterns that arise from a 2D shear driven annular flow (without and with melting), are presented. The convective annular flow with radial gravity can be considered as a simplified model of the atmospheric flow in the terrestrial equatorial plane (bounded by the warm surface of the Earth and the cold tropopause). The governing equations have been numerically solved by the Spectral Element Method. The numerical results reported in this paper, for the cases without melting (at two… More >

Mustapha FARAJI¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 19-36, 2017, DOI:10.3970/fdmp.2017.013.019

Abstract A two-dimensional numerical model that accounts for heat transfer by conduction and natural convection in the molten region of nano enhanced Phase Change Material (PCM) is performed. Numerical investigations were conducted using an enthalpy- porosity method in order to examine the impact of the dispersion of copper (CuO) nanoparticles on the heat source temperature and the effect on the heat sink secured working time and the melting rate. Results show that heat spreads more easily along the conducting plate and to the PCM and, consequently, the PCM melts rapidly and the heat source is efficiency cooled by the addition of… More >

Mustapha Faraji¹, El Alami Mustapha, Najam Mostafa

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 279-298, 2014, DOI:10.3970/fdmp.2014.010.279

Abstract A study is reported of heat transfer and melting in a fan-less thermal management system consisting of an insulated horizontal cavity filled with a phase change material (PCM) and heated from below by a conducting plate supporting three identical protruding heat sources. Such a PCM enclosure can be used as a heat sink for the cooling of electronic components. The advantage of this cooling strategy is that PCMs characterized by high energy storage density and small transition temperature interval, are able to store a high amount of heat (thereby providing efficient passive cooling). A two-dimensional simulation model is developed that… More >

A. Arid¹, T. Kousksou¹, S.Jegadheeswaran², A. Jamil³, Y. Zeraouli¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 257-276, 2012, DOI:10.3970/fdmp.2012.008.257

Abstract A two-dimensional numerical model has been developed to investigate the phase-change of ice near 4 °C in a rectangular cavity. The enthalpy-porosity model is reformulated in terms of conservation equations of mass, momentum and heat to account for the evolution the solid/liquid interface. Constant and time-dependent (with sinusoidal law) temperature boundary conditions are considered. Results confirm the possibility to control the typical dynamics of ice melting in a square cavity near the density inversion point by means of a wall temperature which varies in time (with given amplitude and frequency). More >