Primož Kocutar^{1, *}, Jure Ravnik¹, Leopold Škerget¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 1-22, 2020, DOI:10.32604/cmes.2020.08728 - 01 April 2020

Abstract In this paper, we develop and test a unified hybrid LES/URANS turbulence model with two different Large Eddy Simulation (LES) turbulence models. The numerical algorithm is based on the Boundary Element Method. In the existing hybrid LES/URANS turbulence model we implemented a new Smagorinsky LES turbulence model. The hybrid LES/URANS turbulence model is unified, which means that the LES/URANS interface is changed dynamically during simulation using a physical quantity. In order to define the interface between LES and unsteady Reynolds Averaged Navier Stokes (URANS) zones during the simulation, we use the Reynolds number based on… More >

Yasir Nawaz¹, Muhammad Shoaib Arif ¹, Mairaj Bibi^{2, *}, Javeria Nawaz Abbasi², Umer Javed³, Amna Nazeer²

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 657-677, 2020, DOI:10.32604/cmc.2020.08584

Abstract Present contribution is concerned with the construction and application of a numerical method for the fluid flow problem over a linearly stretching surface with the modification of standard Gradient descent Algorithm to solve the resulted difference equation. The flow problem is constructed using continuity, and Navier Stoke equations and these PDEs are further converted into boundary value problem by applying suitable similarity transformations. A central finite difference method is proposed that gives third-order accuracy using three grid points. The stability conditions of the present proposed method using a Gauss-Seidel iterative procedure is found using VonNeumann… More >

Ravi Datt^a,b , Anil Kumar^c,*, Mangal Singh Bhist^d , Alok Darshan Kothiyal^e , Rajesh Maithani^f

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-19, 2019, DOI:10.5098/hmt.12.26

Abstract This work presents a review of the research recent results concerning the augmentation of hydrodynamic and thermal performance of various twisted tape inserts in heat exchanger tubes. The thermal and hydrodynamic correlations for various twisted tape elements have been summarized. A comparative study of thermal and hydrodynamic performance of numerous twisted elements has also been reported to understand the result of applications of twisted tape inserts in heat exchanger tubes. The literature review found that multiple twisted tapes heat exchanger tube shape enhanced hydrodynamic and thermal performance than other comparable twisted tape inserts heat exchanger More >

Qingxin Ba^a , Scott Egbert^b, Xuefang Li^a,* , Lin Cheng^a,**

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.20

Abstract Precalciner performance is crucial to the production rate and lifespan of cement kiln systems. The gas-solid flow and pulverized coal combustion processes in an industrial precalciner were numerically modeled to understand the flow patterns and thermal processes in the system. The gas and meal flow rates and properties were measured on-site to determine the boundary conditions for the simulations and to validate the models. The upward swirl of the gas flow in the furnace helped disperse the particles and extend their duration in the precalciner. The O₂ and CO₂ concentration distributions indicated that the coal particles More >

Shina D. Oloniiju^† , Sicelo P. Goqo, Precious Sibanda

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-8, 2019, DOI:10.5098/hmt.13.19

Abstract In some recent studies, it has been suggested that non–Newtonian fluid flow can be modeled by a spatially non–local velocity, whose dynamics are described by a fractional derivative. In this study, we use the space fractional constitutive relation to model heat and mass transfer in a nanofluid. We present a numerically accurate algorithm for approximating solutions of the system of fractional ordinary differential equations describing the nanofluid flow. We present numerically stable differentiation matrices for both integer and fractional order derivatives defined by the one–sided Caputo derivative. The differentiation matrices are based on the series More >

Anupam Bhandari^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.5, pp. 557-582, 2019, DOI:10.32604/fdmp.2019.04108

Abstract The present research aims to examine the steady state of the two-dimensional incompressible magnetohydrodynamics (MHD) flow of a micropolar nanofluid over a stretching sheet in the presence of chemical reactions, radiation and viscous dissipation. The effect of particle rotation is taken into account. A conducting fluid passes over a semi-infinite plate with variable temperature while a magnetic field is directed in the transverse direction. Results for velocity, angular momentum, temperature and concentration profiles are obtained for various values of Eckert number, Schmidt number, Prandtl number, thermophosis parameter and Brownian motion parameters. A similarity approach is… More >

MD. Shamshuddin^{1, *}, C. Balarama Krishna²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.3, pp. 207-231, 2019, DOI:10.32604/fdmp.2019.00449

Abstract Mathematical model for an unsteady, incompressible, electrically conducting micropolar fluid past a vertical plate through porous medium with constant plate velocity has been investigated in the present study. Heat absorption, Joulian dissipation, and firstorder chemical reaction is also considered. Under the assumption of low Reynolds number, the governing transport equations are rendered into non-dimensional form and the transformed first order differential equations are solved by employing an efficient finite element method. Influence of various flow parameters on linear velocity, microrotation velocity, temperature, and concentration are presented graphically. The effects of heat absorption and chemical reaction More >

Minshan Li^1,3, Dongchuan Mo^2,3*, Shushen Lyu^2,3*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 165-165, 2019, DOI:10.32604/icces.2019.05510

Abstract In the past few years, machine learning algorithms and models have shown great power in the emerging field of data mining and artificial intelligence, attracting a great deal of attention. Given specific learning task and training data set, a machine learning model can improve automatically through training and can help people make decisions and predictions. To date, a lot of advanced machine learning algorithms and theories have been proposed and developed, including random forest, support vector machine, artificial neural network, deep learning and so on. Well-chosen and well-trained machine learning model is proved to have… 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 >

Long Jiao^1,2, Zhibin Wang^1,2, Rong Chen^1,2,*, Xun Zhu^1,2, Qiang Liao^1,2, Dingding Ye^1,2, Biao Zhang^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 144-146, 2019, DOI:10.32604/icces.2019.04734

Abstract With the advances in micro total analysis systems (µTAS), the droplet-based microfluidics, which manipulates mini discrete droplets in an immiscible continuous phase to accomplish various detections, has been applied to many fields including medicine, pharmacy, fine-chemistry and biotechnology as it offers distinct advantages, such as small diffusion length, high-throughput, precise control and integratability [1]. As compared to the continuous-flow microfluidics, the samples in the droplet-based microfluidics are isolated by a defined droplet/continuous phase interface, avoiding the cross contamination and resulting in a controllable reaction environment. In the droplet-based microfluidics, the control of the droplet temperature… More >