R. Shamsoddini, N. Aminizadeh1, M. Sefid

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.3, pp. 209-230, 2015, DOI:10.3970/cmes.2015.105.209

Abstract In this study, an improved weakly compressible Smoothed Particle Hydrodynamics method is introduced and applied for investigation of the non- Newtonian power-law fluid flow which is induced by motion of a square cylinder. The method is based on a predictor-corrector scheme and pressure velocity coupling to overcome the non-physical fluctuations of WCSPH. The numerical method is also supported by the corrective tensors and shifting algorithm. The results are validated against the well known test cases and benchmark data. The square motion is tested in various Reynolds numbers for various power law indices. The results show More >

Suripeddi Srinivas^a , Akshay Gupta^b,*, Ashish Kumar Kandoi^b

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-12, 2014, DOI:10.5098/hmt.5.21

Abstract The present work deals with the flow and thermal analysis of nanofluid in the wavy channels. The governing flow equations are solved numerically using CFD package assuming single phase approach. To study the effect of the concentration and size variation of the nanoparticle, the concentration and size are varied from 0% - 5% and 25 nm - 100 nm respectively over the Reynolds number range of 250-1500 for Au-water nanofluid. The effect on heat transfer enhancement because of corrugation of wavy channel is analyzed on four different shapes (sinusoidal, triangular, trapezoidal and square) channels. The More >

Lei Lu^1,2, Li-Hua Liu^3,4, Xiao-Xiao Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.1, pp. 1-15, 2014, DOI:10.3970/cmes.2014.101.001

Abstract In this paper, we use the modified decomposition method (MDM) to solve the unsteady flow of a nanofluid squeezing between two parallel equations. Copper as nanoparticle with water as its base fluid has considered. The effective thermal conductivity and viscosity of nanofluid are calculated by the Maxwell- Garnetts (MG) and Brinkman models, respectively. The effects of the squeeze number, the nanofluid volume fraction, Eckert number, δ on Nusselt number and the Prandtl number are investigated. The figures and tables clearly show high accuracy of the method to solve the unsteady flow. More >

N. Pham-Sy¹, C.-D. Tran¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.5, pp. 363-397, 2014, DOI:10.3970/cmes.2014.100.363

Abstract In this paper, a high performance computing method based on the Integrated Radial Basis Function (IRBF), Control Volume (CV) and Domain Decomposition technique for solving Partial Differential Equations is presented. The goal is to develop an efficient parallel algorithm based on the Compact Local IRBF method using the CV approach, especially for problems with non-rectangular domain. The results showed that the goal is achieved as the computational efficiency is quite significant. For the case of square lid driven cavity problem with Renoylds number 100, super-linear speed-up is also achieved. The parallel algorithm is implemented in More >

Anupam Bh,ari¹, Vipin Kumar²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 359-375, 2014, DOI:10.3970/fdmp.2014.010.359

Abstract The purpose of this paper is to study the flow characteristics of a ferrofluid revolving through a porous medium with a magnetic-field-dependent viscosity in the presence of a stationary disk. A Finite Difference Method is employed to discretize the set of nonlinear coupled differential equations involved in the problem. The discretized nonlinear equations, in turn, are solved by a Newton method (using MATLAB) taking the initial guess with the help of a PDE Solver. Results displayed in graphical form are used to assess the effect of the variable viscosity and porosity parameters on the velocity More >

N. Thai-Quang¹, N. Mai-Duy¹, C.-D. Tran¹, T. Tran-Cong^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.1, pp. 49-90, 2013, DOI:10.3970/cmes.2013.096.049

Abstract In this paper, we present a numerical scheme, based on the direct forcing immersed boundary (DFIB) approach and compact integrated radial basis function (CIRBF) approximations, for solving the Navier-Stokes equations in two dimensions. The problem domain of complicated shape is embedded in a Cartesian grid containing Eulerian nodes. Non-slip conditions on the inner boundaries, represented by Lagrangian nodes, are imposed by means of the DFIB method, in which a smoothed version of the discrete delta functions is utilised to transfer the physical quantities between two types of nodes. The velocities and pressure variables are approximated More >

K. Kakuda¹, T. Nagashima¹, Y. Hayashi¹, S. Obara¹, J. Toyotani¹, S. Miura², N. Katsurada³, S. Higuchi³, S. Matsuda³

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.5, pp. 363-376, 2013, DOI:10.3970/cmes.2013.093.363

Abstract The application of a GPU-based particle method to three-dimensional incompressible viscous fluid flow problems is presented. The particle approach is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic weighting function to stabilize the spurious oscillatory solutions for solving the Poisson equation with respect to the pressure fields by using GPU-based SCG (Scaled Conjugate Gradient) method. Numerical results demonstrate the workability and the validity of the present approach through the dam-breaking flow problem and flow behavior in a liquid ring pump with rotating impeller blades. More >

Md. Farhad Ismail^a,*, M.A.I. Rashid^b , M. Mahbub^b

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-8, 2012, DOI:10.5098/hmt.v3.3.3002

Abstract Carbon nanotube (CNT) has been proven to be an effective material for the thermal management of MEMS-based devices due to its superior thermal conductivity. At the same time, micro-channel heat-sinks are widely used in electronic products as a high performance heat transfer device because of its simple construction, easy fabrication process and effective heat removal capability. A numerical study has been carried out to investigate the thermal-fluid characteristics of the aligned and staggered MWCNT (multi walled CNT) based micro pin fins having 650 µm long with hydraulic diameter of ~130 µm. Average heat transfer coefficients More >

Kazuhiko Kakuda¹, Tsuyoki Nagashima¹, Yuki Hayashi¹, Shunsuke Obara¹, Jun Toyotani¹, Nobuya Katsurada², Shunji Higuchisup>2, Shohei Matsuda²

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.1, pp. 17-28, 2012, DOI:10.3970/cmes.2012.088.017

Abstract An acceleration of the particle-based incompressible fluid flow simulations on GPU using CUDA is presented. The particle method is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic-type weighting function to stabilize the spurious oscillatory solutions for the pressure fields which are governed by Poisson equation. The standard MPS scheme is widely utilized as a particle strategy for the free surface flow, the problem of moving boundary, multi-physics/multi-scale ones, and so forth. Numerical results demonstrate the workability and the validity of the present approach through dam-breaking flow problem. More >

C.-D. Tran¹, N. Mai-Duy^1,1, K. Le-Cao¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.6, pp. 499-520, 2012, DOI:10.3970/cmes.2012.085.499

Abstract A numerical computation of continuum-microscopic model for visco-elastic flows based on the Integrated Radial Basis Function (IRBF) Control Volume and the Stochastic Simulation Techniques (SST) is reported in this paper. The macroscopic flow equations are closed by a stochastic equation for the extra stress at the microscopic level. The former are discretised by a 1D-IRBF-CV method while the latter is integrated with Euler explicit or Predictor-Corrector schemes. Modelling is very efficient as it is based on Cartesian grid, while the integrated RBF approach enhances both the stability of the procedure and the accuracy of the More >