Fluid-Structure Interaction and Control Around Vibrating and Morphing Configurations at High Reynolds Number

Author(s):  
G. Jodin ◽  
N. Simiriotis ◽  
A. Aalilija ◽  
A. Marouf ◽  
Y. Hoarau ◽  
...  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mustafa Serdar Genç ◽  
Hacımurat Demir ◽  
Mustafa Özden ◽  
Tuna Murat Bodur

Purpose The purpose of this exhaustive experimental study is to investigate the fluid-structure interaction in the flexible membrane wings over a range of angles of attack for various Reynolds numbers. Design/methodology/approach In this paper, an experimental study on fluid-structure interaction of flexible membrane wings was presented at Reynolds numbers of 2.5 × 104, 5 × 104 and 7.5 × 104. In the experimental studies, flow visualization, velocity and deformation measurements for flexible membrane wings were performed by the smoke-wire technique, multichannel constant temperature anemometer and digital image correlation system, respectively. All experimental results were combined and fluid-structure interaction was discussed. Findings In the flexible wings with the higher aspect ratio, higher vibration modes were noticed because the leading-edge separation was dominant at lower angles of attack. As both Reynolds number and the aspect ratio increased, the maximum membrane deformations increased and the vibrations became visible, secondary vibration modes were observed with growing the leading-edge vortices at moderate angles of attack. Moreover, in the graphs of the spectral analysis of the membrane displacement and the velocity; the dominant frequencies coincided because of the interaction of the flow over the wings and the membrane deformations. Originality/value Unlike available literature, obtained results were presented comparatively using the sketches of the smoke-wire photographs with deformation measurement or turbulence statistics from the velocity measurements. In this study, fluid-structure interaction and leading-edge vortices of membrane wings were investigated in detail with increasing both Reynolds number and the aspect ratio.


Author(s):  
Todd H. Weisgraber ◽  
Stuart D. C. Walsh ◽  
Kostas Karazis ◽  
Dennis Gottuso

Many challenging fluid-structure interaction problems in nuclear engineering remain unresolved because current CFD methodologies are unable to manage the number of computational cells needed and/or the difficulties associated with meshing changing geometries. One of the most promising recent methodologies for fluid dynamics modeling is the lattice-Boltzmann method — an approach that offers significant advantages over classical CFD methodologies by 1) greatly reducing meshing requirements, 2) offering great scalability, and 3) through relative ease of code parallelization. While LBM often requires increased numerical effort compared to other methods, this can be dramatically reduced by combining LBM with Adaptive Mesh Refinement (LB-AMR). This study describes an ongoing collaboration investigating nuclear fuel-assembly spacer grid performance. The LB-AMR method, used to simulate the flow field around a specific spacer grid design, is capable of describing turbulent flows for high Reynolds numbers, revealing rich flow dynamics in good qualitative agreement with experimental results. Prepared by LLNL under Contract DE-AC52-07NA27344.


Author(s):  
R. Madhumitha ◽  
S. Arunkumar ◽  
K. K. Karthikeyan ◽  
S. Krishnah ◽  
V. Ravichandran ◽  
...  

Abstract A passive micromixer with obstacles in the form of deformable baffles is examined numerically. The model deploys an Arbitrary Lagrangian-Eulerian framework with Fluid-structure interaction coupled with a diffusion–advection model. Numerical analysis is carried out in the Reynolds number [Re] range of 0.01≤Re≤300. The objective of the present study is to enhance mixing between two component flow streams in a microchannel encompassing a deformable baffle. In the present work, the baffle deforms only due to the dynamic force of fluids. No external forces are applied. To exemplify the effectiveness of the present design, water and a suspension of curcumin drug loaded nanoparticles are taken as two fluids. Mixing index based on the variance of the local concentration of the suspension is employed to appraise the mixing performance of the micromixer. The introduction of the deformable baffle in a micromixer proliferates the mixing performance with minimal pressure drop over the tested Reynolds number range.


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