Computationally Efficient Large-Eddy Simulation of Periodic Unsteady Flow using Harmonic Balance Method

2022 ◽  
Vol 31 (1) ◽  
pp. 62-71
Author(s):  
Iwamoto Yuma ◽  
Teramoto Susumu ◽  
Okamoto Koji
Keyword(s):  
Large Eddy Simulation ◽  
Unsteady Flow ◽  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Balance Method ◽  
Computationally Efficient ◽  
Eddy Simulation ◽  
Large Eddy

Extension of Harmonic Balance Approach for Large-Eddy Simulation of Unsteady Flows in Cascade

2021 ◽  
Author(s):  
Yuma Iwamoto ◽  
Susumu Teramoto ◽  
Koji Okamoto
Keyword(s):  
Large Eddy Simulation ◽  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Turbulence Models ◽  
Small Scale ◽  
Turbulent Fluctuations ◽  
Eddy Simulation ◽  
Balance Approach ◽  
Large Eddy ◽  
Periodic Components

Abstract A full scale-resolving simulation of cascades flutter is time consuming because of computational inefficiency owing to its low nondimensional frequencies. To improve the efficiency and reliability of the numerical analyses for such flows, we propose an efficient scale-resolving simulation method dedicated to time-periodic flows by extending the harmonic balance approach to a large-eddy simulation. This method combines convergence calculations of the steady-state problem based on the harmonic balance method for periodic components, and the nonlinear time-marching method for small scale turbulent fluctuations. Using the proposed method, deterministic periodic components and stochastic turbulent fluctuations are calculated simultaneously, and the effect of turbulent fluctuations on deterministic periodic components is directly calculated without using turbulence models. In this paper, we present the algorithm of the simulation technique and the progress of validation calculations for channel flow excited in the streamwise direction.

On the performance of harmonic balance method for unsteady flow with oscillating shocks

2020 ◽  
Vol 32 (12) ◽  
pp. 126103
Author(s):  
Di Zhou ◽  
Zhiliang Lu ◽  
Tongqing Guo ◽  
Guoping Chen
Keyword(s):  
Unsteady Flow ◽  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Balance Method

Simulation of Unsteady Turbomachinery Flows Using an Implicitly Coupled Nonlinear Harmonic Balance Method

2011 ◽  
Author(s):  
Jonathan M. Weiss ◽  
Venkataramanan Subramanian ◽  
Kenneth C. Hall
Keyword(s):  
Steady State ◽  
Harmonic Balance ◽  
Time Derivative ◽  
Computational Cost ◽  
Harmonic Balance Method ◽  
Balance Method ◽  
Computationally Efficient ◽  
State Equations ◽  
Approximate Factorization ◽  
Efficient Manner

A nonlinear harmonic balance method for the simulation of turbomachinery flows is presented. The method is based on representing an unsteady, time periodic flow by a Fourier series in time and then solving a set of mathematically steady-state equations to obtain the Fourier coefficients. The steady-state solutions are stored at discrete time levels distributed throughout one period of unsteadiness and are coupled via the physical time derivative and at periodic boundaries. Implicit coupling between time levels is achieved in a computationally efficient manner through approximate factorization of the linear system that results from the discretized equations. Unsteady, rotor-stator interactions are performed to validate the implementation. Results based on the harmonic balance method are compared against those obtained using a full unsteady, time-accurate calculation using moving meshes. The implicitly coupled nonlinear harmonic balance method is shown to produce a solution of reasonable accuracy compared to the full unsteady approach but with significantly less computational cost.

scholarly journals Large-Eddy Simulation of Unsteady Flow in a Mixed-Flow Pump

2003 ◽  
Vol 9 (5) ◽  
pp. 345-351 ◽  
Author(s):  
Chisachi Kato ◽  
Hiroshi Mukai ◽  
Akira Manabe
Keyword(s):  
Large Eddy Simulation ◽  
Unsteady Flow ◽  
Mixed Flow ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Pump

Prediction of Pressure Fluctuation on a Vehicle by Large Eddy Simulation

2015 ◽  
Author(s):  
Yoshinobu Yamade ◽  
Chisachi Kato ◽  
Akiyoshi Iida ◽  
Shinobu Yoshimura ◽  
Keiichiro Iida
Keyword(s):  
Structural Analysis ◽  
Large Eddy Simulation ◽  
Unsteady Flow ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Sound Fields ◽  
Eddy Simulation ◽  
Acoustical Analysis ◽  
Wide Range ◽  
Large Eddy

The objective of this study is to predict accurately interior aeroacoustics noise of a car for a wide range of frequency between 100 Hz and 4 kHz. One-way coupled simulations of computational fluid dynamics (CFD), structural analysis and acoustical analysis were performed to predict interior aeroacoustics noise. We predicted pressure fluctuations on the outer surfaces of a test car by computing unsteady flow around the car as the first step. Secondary, the predicted pressure fluctuations were fed to the subsequent structural analysis to predict vibration accelerations on the inner surfaces of the test car. Finally, acoustical analysis was performed to predict sound fields in the test car by giving vibration accelerations computed by the structural analysis as the boundary conditions. In this paper, we focus on the unsteady flow computations, which is the first step of the coupled simulations. Large Eddy Simulation (LES) was performed to predict the pressure fluctuations on the outer surfaces of the test car. We used the computational mesh composed of approximately 5 billion hexahedral grids with a spatial resolution of 1.5 mm in the streamwise and spanwise directions to resolve the dynamics of the small vortices in the turbulence boundary layer. Predicted and measured pressure fluctuation at several sampling points on the surface of the test car were compared and they matched well in a wide range of frequency up to 2 kHz.

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