A detailed study of the parallel performance of the interpolation supplemented lattice Boltzmann (ISLB) method using SHMEM and MPI on the Cray T3E-900 and Cray X1 architectures is presented. The noteworthy feature of the present implementation of the ISLB method is that it is able to achieve a sustained speed of 4.2 Tflop/s while using 504 processors on a Cray X1. The code is shown to achieve super-linear speedups on the Cray T3E-900. It is shown through detailed profiling that the computation and the communication scale well on the Cray X1, although the overall speedup is adversely affected by the cost of barrier synchronization. © 2006 Sage Publications.

Viswanathan T. Babu

Department of Mechanical Engineering

Computation theory

interpolation

Mathematical models

MULTIPROCESSING PROGRAMS

performance

BARRIER SYNCHRONIZATION

INTERPOLATION SUPPLEMENTED LATTICE BOLTZMANN (ISLB) METHOD

Performance analysis

SUPER-LINEAR SPEEDUPS

Parallel processing systems

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

A Detailed Performance Analysis of the Interpolation Supplemented Lattice Boltzmann Method on the Cray T3E and Cray X1A Detailed Performance Analysis of the Interpolation Supplemented Lattice Boltzmann Method on the Cray T3E and Cray X1

International Journal of High Performance Computing Applications

An axisymmetric compact finite-difference lattice Boltzmann method is proposed to simulate both Newtonian and non-Newtonian flow of blood through a lumen. The curvature of the arteries could be accurately resolved using body-fitted mesh owing to the proposed finite-difference formulation. The axisymmetric nature of the flow, as well as the non-Newtonian nature of blood, are incorporated into the lattice Boltzmann equation using separate source terms. Using Chapman-Enskog expansion it is shown that the resulting lattice Boltzmann equation with these additional source terms recovers the macroscopic axisymmetric hydrodynamic equations. The solver is verified for (1) steady inflow of a Newtonian fluid through a stenosed lumen, (2) temporally developing pulsatile flow (Womersley flow) through a straight lumen with Newtonian fluid, and (3) steady inflow of a non-Newtonian fluid through a straight lumen. The solver is then applied to simulate the steady flow of a non-Newtonian fluid through a stenosed lumen, and it was found that a smaller recirculation zone and lower WSS values are obtained when compared with the flow of a Newtonian fluid. The capability of the solver to simulate spatially developing (velocity-driven) pulsatile flow is then demonstrated by simulating physiological pulsatile flow through an axisymmetric abdominal aortic aneurysm. From this simulation, the cycle-averaged wall shear stress is observed to have a steep gradient going from a minimum (negative) to a maximum (positive) value towards the distal end of the aneurysm, which is prone to the risk of rupture. An iterative procedure to select the geometric and flow parameters for unsteady inflow condition in the lattice Boltzmann method framework is demonstrated that accurately resolves all the timescales to achieve incompressibility. Overall, the present solver seems to be promising to simulate axisymmetric flow of blood with steady and pulsatile inflows while considering the blood rheology. © 2019 American Physical Society.

Physical Review E

Axisymmetric compact finite-difference lattice Boltzmann method for blood flow simulations

Lattice Boltzmann method (LBM) is employed to investigate natural convection inside porous medium enclosures at high Rayleigh numbers. Volume averaged porous medium model is coupled with the lattice Boltzmann formulation of the momentum and energy equations for fluid flow. A parallel implementation of the single relaxation time LBM is used, which allows the porous medium modified Rayleigh number Ram to be as high as 108. Heat transfer results in the form of the enclosure averaged Nusselt number Nu are obtained for higher modified Rayleigh numbers 104 ≤ Ram ≤ 108. The Nu values are compared with values in the absence of the form drag term. The form drag due to the porous medium is found to influence Nu considerably. The effect of the form drag on Nu is studied by using a form drag modified Rayleigh number RaC (extended from Ram). Utilizing the results for Nu in the high Ram range, a correlation is proposed between Nu and RaC for Darcy numbers 10-6 ≤ Da ≤ 10-2, encompassing the non-Darcy flow regime. © 2011 American Society of Mechanical Engineers.

Journal of Heat Transfer

High Rayleigh number natural convection inside 2D porous enclosures using the lattice Boltzmann method

Journal of Computational Physics

Acceleration of Lattice-BGK Schemes with Grid Refinement

An Accurate Curved Boundary Treatment in the Lattice Boltzmann Method

Annual Review of Fluid Mechanics

LATTICE BOLTZMANN METHOD FOR FLUID FLOWS

Lattice Boltzmann Method on Curvilinear Coordinates System: Flow around a Circular Cylinder

Physica A: Statistical Mechanics and its Applications

Fifty years of kinetic theory

A detailed performance analysis of the interpolation supplemented lattice Boltzmann method on the Cray T3E and Cray X1

Journal	International Journal of High Performance Computing Applications
ISSN	10943420
Open Access	No