Toward Realization of Numerical Towing-Tank Tests by Wall-Resolved Large Eddy Simulation based on 32 Billion Grid Finite-Element Computation

This work is concerned with modeling the interaction of fluid flow with flexible solid structures. An improving spring smooth analogy and an improved constant volume transfer (ICVT) are used to provide fluid mesh control and transfer the information on the interfaces between fluid and structure, respectively. The time integrating algorithm is based on the predictor multi-corrector algorithm (PMA). An important aspect of this work is that we present a directly coupled approach, in which a large eddy simulation (LES) fluid solver and a structure solver have been coupled together to solve a hydroelasticity problem using the finite element method. To demonstrate the performance of the proposed approach, two working examples were used. One is the vibration of a beam immersed in incompressible fluid, another is the hydroelastic behavior of an ideal guide vane in a hydro turbine passage. The numerical results show the validity of the proposed approach.

Download Full-text

Performance of the Finite Element and Finite Volume Methods for Large Eddy Simulation in Homogeneous Isotropic Turbulence

Journal of Scientific Research ◽

10.3329/jsr.v2i2.2582 ◽

2010 ◽

Vol 2 (2) ◽

pp. 237-249 ◽

Cited By ~ 1

Author(s):

M. A. Uddin ◽

C. Kato ◽

N. Oshima ◽

M. Tanahashi ◽

T. Miyauchi

Keyword(s):

Finite Element ◽

Large Eddy Simulation ◽

Finite Volume ◽

Isotropic Turbulence ◽

Finite Volume Methods ◽

Homogeneous Isotropic Turbulence ◽

Smagorinsky Model ◽

Eddy Simulation ◽

Large Eddy ◽

Better Than

Large eddy simulation (LES) in homogeneous isotropic turbulence is performed by using the Finite element method (FEM) and Finite volume vethod (FVM) and the results are compared to show the performance of FEM and FVM numerical solvers. The validation tests are done by using the standard Smagorinsky model (SSM) and dynamic Smagorinsky model (DSM) for subgrid-scale modeling. LES is performed on a uniformly distributed 643 grids and the Reynolds number is low enough that the computational grid is capable of resolving all the turbulence scales. The LES results are compared with those from direct numerical simulation (DNS) which is calculated by a spectral method in order to assess its spectral accuracy. It is shown that the performance of FEM results is better than FVM results in this simulation. It is also shown that DSM performs better than SSM for both FEM and FVM simulations and it gives good agreement with DNS results in terms of both spatial spectra and decay of the turbulence statistics. Visualization of second invariant, Q, in LES data for both FEM and FVM reveals the existence of distinct, coherent, and tube-like vortical structures somewhat similar to those found in instantaneous flow field computed by the DNS. Keywords: Large eddy simulation; Validation; Smagorinsky model; Dynamic Smagorinsky model; Tube-like vortical structure; Homogeneous isotropic turbulence. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v2i2.2582 J. Sci. Res. 2 (2), 237-249 (2010)

Download Full-text