Evaluation of a Near-Wall-Modeled Large Eddy Lattice Boltzmann Method for the Analysis of Complex Flows Relevant to IC Engines

Abstract

In this paper, we compare the capabilities of two open source near-wall-modeled large eddy simulation (NWM-LES) approaches regarding prediction accuracy, computational costs and ease of use to predict complex turbulent flows relevant to internal combustion (IC) engines. The applied open source tools are the commonly used OpenFOAM, based on the finite volume method (FVM), and OpenLB, an implementation of the lattice Boltzmann method (LBM). The near-wall region is modeled by the Musker equation coupled to a van Driest damped Smagorinsky-Lilly sub-grid scale model to decrease the required mesh resolution. The results of both frameworks are compared to a stationary engine flow bench experiment by means of particle image velocimetry (PIV). The validation covers a detailed error analysis using time-averaged and root mean square (RMS) velocity fields. Grid studies are performed to examine the performance of the two solvers. In addition, the differences in the processes of grid generation are highlighted. The performance results show that the OpenLB approach is on average 32 times faster than the OpenFOAM implementation for the tested configurations. This indicates the potential of LBM for the simulation of IC engine-relevant complex turbulent flows using NWM-LES with computationally economic costs.

Applied Geometry Optimization of an Innovative 3D‐Printed Wet‐Scrubber Nozzle with a Lattice Boltzmann Method

“…The implemented ellipsoids are described by the approach of Bouzidi et al [12] to reduce the aberrations of curved objects due to the staircase approximation of the bounce-back approach. The outflow condition uses a wet-node equilibrium boundary condition (see Haussmann et al [4]).…”

“…The applied open-source tool for numerical flow simulations is OpenLB [2,3], which provides an implementation of the lattice Boltzmann method (LBM). Due to its highly efficient parallel algorithm, the LBM has a high potential in simulating turbulent flows with moderate computing time [4].…”

Improved wall model treatment for aerodynamic flows in LBM

“…As discussed in Section 2.1 , the particle distribution functions can be split into the equilibrium component f eq that can be determined by the local fluid density and velocity though Eq. 5 , and the non-equilibrium component f neq .The latter can be obtained in several ways: Haussmann et al [18] extrapolated it from the inside of the fluid following Guo's scheme [63] , Haussmann et al [40] used an interpolated bounce-back operation [41] , Malaspinas and Sagaut [16] exploited the symmetry properties of flat grid-aligned boundaries. The importance of the f neq component to the accuracy of the wall treatment was evidenced by Haussmann et al [18] .…”

“…A hybrid between both families has been proposed [40] by applying a velocity correction on boundary nodes after performing Bouzidi's interpolated bounce-back [41] . Most of these treatments were demonstrated in conjunction with the LES turbulence modeling strategy (WM-LES) [16,18,22,26,33,40] , others with RANS models (WM-RANS) [17,29,32] , and even with a combination of both [19] (WM-RANS-LES).…”

Linear and brute force stability of orthogonal moment multiple-relaxation-time lattice Boltzmann methods applied to homogeneous isotropic turbulence

“…From a third perspective, some contributions [10–17] also provide evidence that specific LBM variants comprise numerical features which resemble implicit turbulence model behaviour through numerical dissipation [18]. In summary, the studies prove that LBM is indeed a reliable method for computational fluid dynamics and in some cases even superior to conventional ones [19,20].…”