Large Eddy Simulations of Side Flows past a Generic Model of a High-Speed-Train using a Finite Volume and a Lattice Boltzmann Method

2016 ◽  
Author(s):  
N. Kin ◽  
R. Deiterding ◽  
C. Wagner
Keyword(s):  
Lattice Boltzmann Method ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
High Speed ◽  
Large Eddy Simulations ◽  
Generic Model ◽  
High Speed Train ◽  
Large Eddy ◽  
Boltzmann Method

Corner Stall Prediction in a Compressor Linear Cascade Using Very Large Eddy Simulation Lattice-Boltzmann Method

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Antoine Maros ◽  
Benoît Bonnal ◽  
Ignacio Gonzalez-Martino ◽  
James Kopriva ◽  
Francesco Polidoro
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Computational Cost ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Compressor Cascade ◽  
Numerical Work ◽  
Large Eddy ◽  
Boltzmann Method ◽  
Linear Compressor Cascade

Abstract Compressor corner stall is a phenomenon difficult to predict with numerical tools but essential to the design of axial compressors. Predictive methods are beneficial early in the design process to understand design and off-design limitations. Prior numerical work using Navier–Stokes computational methods has assessed the prediction capability for corner stall. Reynolds-averaged Navier–Stokes (RANS) simulations using several turbulence models have shown to over-predict the region of corner hub stall where large eddy simulations (LES) and detached eddy simulations (DES) approaches improved the airfoil surface and wake pressure loss prediction. A linear compressor cascade designed and tested at Ecole Centrale de Lyon provides a good benchmark for the evaluation of the accuracy of numerical methods for corner stall. This paper presents results obtained with Lattice-Boltzmann method (LBM) coupled with very large-eddy simulations (VLES) approach of PowerFLOW and compares them with the experimental and numerical work from Ecole Centrale de Lyon. The ability to achieve equivalent accuracy at a lower computational cost compared to LES scale resolving methods can enable multi-stage design and off-design compressor predictions. A methodical approach is taken by first accurately simulating the upstream flow conditions. Geometric trips are modeled upstream on the endwalls to match both the mean and fluctuating inflow boundary layer conditions. These conditions were then applied to the simulation of the linear compressor cascade. The benchline experimental study includes trips on both the pressure and suction of the airfoil. These trips are also included for the current simulation. The significance of capturing both inflow conditions and including trips on the airfoil is assessed. Detailed comparisons are then made to airfoil loading and downstream losses between experiment and previous RANS and LES simulations. LBM-VLES corner stall results of pitchwise averaged total pressure match LES agreement relative to experimental data at 50 times lower computational cost.

Two-dimensional analysis of the influence of windbreaks on airflow over a high-speed train under crosswind using lattice Boltzmann method

2017 ◽  
Vol 232 (3) ◽  
pp. 863-872 ◽  
Author(s):  
Masoud Mohebbi ◽  
Mohammad A Rezvani
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
High Speed ◽  
Two Dimensional ◽  
High Speed Train ◽  
Running Safety ◽  
Dimensional Modeling ◽  
High Speed Trains ◽  
The One ◽  
Boltzmann Method

This research is concerned with identifying the effects of windbreak geometry on attenuating aerodynamic loads that can be strong enough to disturb the running safety of high-speed trains. The idea is to suggest the proper geometry for the windbreaks that can make them more efficient and increase their overall performance. Generally speaking, the desired windbreak is the one that can minimize the aerodynamic forces on the surface of trains. In order to reach such an aim, the flow of air around an Intercity-Express 3 high-speed train has been estimated through a two-dimensional modeling by using the lattice Boltzmann method. The flow of crosswind that hits the train is considered as turbulent. The geometry of the windbreaks including the height, the slot, and the edge angles has been investigated. It has been concluded that the windbreak performance, among other parameters, is highly dependent on its height and edge angle. This research expedites the trail for finding suitable choices of windbreak geometries that can in turn provide a reliable degree of running safety of the railway fleet.

Corner Stall Prediction in a Compressor Linear Cascade Using Very Large Eddy Simulation (VLES) Lattice-Boltzmann Method

2019 ◽  
Author(s):  
Antoine Maros ◽  
Benoît Bonnal ◽  
Ignacio Gonzalez-Martino ◽  
James Kopriva ◽  
Francesco Polidoro
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Computational Cost ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Compressor Cascade ◽  
Numerical Work ◽  
Large Eddy ◽  
Boltzmann Method ◽  
Linear Compressor Cascade

Abstract Compressor corner stall is a phenomenon difficult to predict with numerical tools but essential to the design of axial compressors. Predictive methods are beneficial early in the design process to understand design and off-design limitations. Prior numerical work using Navier-Stokes computational methods have assessed the prediction capability for corner stall. Reynolds Averaged Navier-Stokes (RANS) simulations using several turbulence models [1] have shown to over-predict the region of corner hub stall where Large Eddy Simulations (LES) and Detached Eddy Simulations (DES) approaches improved the airfoil surface and wake pressure loss prediction [2, 3]. A linear compressor cascade designed and tested at Ecole Centrale de Lyon [3,4] provides a good benchmark for the evaluation of the accuracy of numerical methods for corner stall. This paper presents results obtained with Lattice-Boltzmann Method (LBM) coupled with Very Large-Eddy Simulations (VLES) approach of PowerFLOW and compares them with the experimental and numerical work from Ecole Centrale de Lyon. The ability to achieve equivalent accuracy at a lower computational cost compared to LES scale resolving methods can enable multi-stage design and off-design compressor predictions. A methodical approach is taken by first accurately simulating the upstream flow conditions. Geometric trips are modeled upstream on the endwalls to match both the mean and fluctuating inflow boundary layer conditions. These conditions were then applied to the simulation of the linear compressor cascade. The benchline experimental study includes trips on both the pressure and suction of the airfoil. These trips are also included for the current simulation. The significance of capturing both inflow conditions and including trips on the airfoil are assessed. Detailed comparisons are then made to airfoil loading and downstream losses between experiment and previous RANS and LES simulations. LBM-VLES corner stall results of pitchwise averaged total pressure match LES agreement relative to experimental data at 50 times lower computational cost.

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