scholarly journals Validation of the Lattice Boltzmann Method for Simulation of Aerodynamics and Aeroacoustics in a Centrifugal Fan

Acoustics ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 735-752
Author(s):  
Rebecca Schäfer ◽  
Martin Böhle
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Experimental Studies ◽  
Pressure Rise ◽  
Direct Calculation ◽  
Quantitative Prediction ◽  
Centrifugal Fan ◽  
Noise Sources ◽  
Flow Features ◽  
Boltzmann Method

Due to the fact that legal and market requirements are becoming stricter, fan noise reduction, in addition to energy efficiency, represent a challenge for fan product designers. Most experimental studies are associated with trial-and-error approaches. Therefore, numerical methods are mostly preferable. However, the quantitative prediction of the noise emitted by radial fans via numerical simulations remains challenging. The Lattice Boltzmann method (LBM) is a relatively new approach that promises a direct calculation of the aerodynamics coupled with the aeroacoustics. This article presents an LBM simulation of a centrifugal fan using the commercial Lattice Boltzmann Code SIMULIA PowerFLOW of Dassault Systèmes. The simulation model includes both the fan impeller and the spiral housing. In accordance with the experimental setup, the fan was mounted in a test bench to analyze four different operating points. The results of the LBM simulation were validated by experimental measurements. Flow information in terms of pressure rise and efficiency of the centrifugal fan as a function of the flow rate are in a good agreement. Considering the acoustic spectra and the blade passing frequency, the simulation was able to precisely predict the noise of the centrifugal fan. The simulation results are also used to visualize the flow and acoustic field inside of the fan to detect noise-generating flow features. By evaluating the filtered pressure fluctuation in the fluid volume and on the wall, four main noise sources of the centrifugal fan can be identified.

HVAC Blower Aeroacoustics Predictions Based on the Lattice Boltzmann Method

2011 ◽  
Author(s):  
Franck Pe´rot ◽  
Min-Suk Kim ◽  
Koichi Wada ◽  
Koji Norisada ◽  
Motohiro Kitada ◽  
...  
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Standard Procedure ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Acoustic Measurements ◽  
Noise Sources ◽  
Flow Information ◽  
Flow Induced Noise ◽  
Boltzmann Method

Two centrifugal HVAC fan and casing geometries are experimentally and numerically investigated. Aerodynamic and acoustic measurements are performed at three operating conditions following an ISO standard procedure. Explicit and compressible CFD/CAA simulations based on the Lattice Boltzmann Method are performed for six configurations. From these simulations, flow information in term of pressure rise as a function of the mass flow rate and noise are obtained at the same time and compared to experiments. Additional post-processing is performed to have an insight on the origin and location of flow-induced noise sources.

An Investigation of the Lattice Boltzmann Method for Large Eddy Simulation of Complex Turbulent Separated Flow

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Kannan N. Premnath ◽  
Martin J. Pattison ◽  
Sanjoy Banerjee
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Scale Model ◽  
Computational Technique ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Features ◽  
Boltzmann Method

Lattice Boltzmann method (LBM) is a relatively recent computational technique for fluid dynamics that derives its basis from a mesoscopic physics involving particle motion. While the approach has been studied for different types of fluid flow problems, its application to eddy-capturing simulations of building block complex turbulent flows of engineering interest has not yet received sufficient attention. In particular, there is a need to investigate its ability to compute turbulent flow involving separation and reattachment. Thus, in this work, large eddy simulation (LES) of turbulent flow over a backward facing step, a canonical benchmark problem which is characterized by complex flow features, is performed using the LBM. Multiple relaxation time formulation of the LBM is considered to maintain enhanced numerical stability in a locally refined, conservative multiblock gridding strategy, which allows efficient implementation. Dynamic procedure is used to adapt the proportionality constant in the Smagorinsky eddy viscosity subgrid scale model with the local features of the flow. With a suitable reconstruction procedure to represent inflow turbulence, computation is carried out for a Reynolds number of 5100 based on the maximum inlet velocity and step height and an expansion ratio of 1.2. It is found that various turbulence statistics, among other flow features, in both the recirculation and reattachment regions are in good agreement with direct numerical simulation and experimental data.

scholarly journals Numerical analysis of aerodynamic noise from pantograph in high-speed trains using lattice Boltzmann method

2019 ◽  
Vol 11 (7) ◽  
pp. 168781401986399 ◽  
Author(s):  
Hee-Min Noh
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
High Speed ◽  
Aerodynamic Noise ◽  
Noise Generation ◽  
Noise Sources ◽  
High Speed Trains ◽  
Boltzmann Method

A pantograph in contact with a catenary for power supply is one of the major aerodynamic noise sources in high-speed trains. To reduce pantograph noise, it is essential to understand the noise generation mechanism of the pantograph. However, it is difficult to determine this mechanism through measurement. Therefore, in this study, the aerodynamic and acoustic performances of a pantograph in a high-speed train were investigated through numerical analysis using the lattice Boltzmann method. First, a real-scaled pantograph was modeled through computer-aided design. Then, the surface and volume meshes of the pantograph model were generated for simulation analysis. Numerical simulation was conducted at a speed of 300 km/h based on the lattice Boltzmann method. Based on the time derivative analysis of flow pressures, it was concluded that the panhead, joint, and base were the dominant noise sources in the pantograph. In particular, various vortexes were generated from the metalized carbon strip of the panhead. The peaks of the sound pressure level propagated from the panhead were 242, 430, and 640 Hz. The noise generation mechanism was analyzed through numerical simulation using noise characteristics.

Aeroacoustic simulation of a cross-flow fan using lattice Boltzmann method with a RANS model

2021 ◽  
Vol 263 (6) ◽  
pp. 598-609
Author(s):  
Kazuya Kusano ◽  
Masato Furukawa ◽  
Kenichi Sakoda ◽  
Tomoya Fukui
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Computational Cost ◽  
Cross Flow ◽  
Pressure Rise ◽  
Navier Stokes ◽  
Immersed Boundary ◽  
Boltzmann Method ◽  
Cross Flow Fan

The present study developed an unsteady RANS approach based on the lattice Boltzmann method (LBM), which can perform direct aeroacoustic simulations of low-speed fans at lower computational cost compared with the conventional LBM-LES approach. In this method, the k-ω turbulence model is incorporated into the LBM flow solver, where the transport equations of k and ω are also computed by the lattice Boltzmann method, similar to the Navier-Stokes equations. In addition, moving boundaries such as fan rotors are considered by a direct-forcing immersed boundary method. This numerical method was validated in a two-dimensional simulation of a cross-flow fan. As a result, the simulation was able to capture an eccentric vortex structure in the rotor, and the pressure rise by the work of the rotor can be reproduced. Also, the peak sound of the blade passing frequency can be successfully predicted by the present method. Furthermore, the simulation results showed that the peak sound is generated by the interaction between the rotor blade and the flow around the tongue part of the casing.

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