NUMERICAL SIMULATION OF FLOW FEATURES AND ENERGY EXCHANGE PHYSICS IN NEAR-WALL REGION WITH FLUID-STRUCTURE INTERACTION

Large eddy simulation is used to explore flow features and energy exchange physics between turbulent flow and structure vibration in the near-wall region with fluid–structure interaction (FSI). The statistical turbulence characteristics in the near-wall region of a vibrating wall, such as the skin frictional coefficient, velocity, pressure, vortices, and the coherent structures have been studied for an aerofoil blade passage of a true three-dimensional hydroturbine. The results show that (i) FSI greatly strengthens the turbulence in the inner region of y+ < 25; and (ii) the energy exchange mechanism between the flow and the vibration depends strongly on the vibration-induced vorticity in the inner region. The structural vibration provokes a frequent action between the low- and high-speed streaks to balance the energy deficit caused by the vibration. The velocity profile in the inner layer near the vibrating wall has a significant distinctness, and the viscosity effect of the fluid in the inner region decreases due to the vibration. The flow features in the inner layer are altered by a suitable wall vibration.

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Fluid Structure Interaction Simulation of a Benchmark Configuration With a Stress Blended-Eddy Simulation Model

Volume 10: Fluids Engineering ◽

10.1115/imece2020-23101 ◽

2020 ◽

Author(s):

Hariyo P. S. Pratomo

Keyword(s):

Reynolds Number ◽

Turbulent Flow ◽

Fluid Structure Interaction ◽

Flow Simulation ◽

Reference Value ◽

Spanwise Direction ◽

Test Case ◽

Wall Region ◽

Fluid Structure ◽

Structure Interaction

Abstract In this work, the application of a shear stress transport based-RANS/LES turbulence modelling approach on a fluid-structure interaction (FSI) benchmark is considered after a transient computation of turbulent flow over the configuration on an LES quality mesh is to be performed. Within the unsteady decoupled simulation the scale resolving method successfully produces complex unsteady eddy sizes behind the reference test case. At a subcritical Reynolds number, a numerical Strouhal number of 0.184 which is close to a reference value of 0.18 is demonstrated by the RANS/LES turbulence model. In this scenario, a rubber added on the back part of a fixed circular cylinder is treated as a rigid thin plate during the pure flow simulation. On the LES grid resolution, the shielding function resided in the hybrid limiter of the scale resolving formulation is found to be strong to safeguard the activation of the RANS mode in the near wall region where the demarcation line between the RANS and LES modes uniquely resembles the geometry. Moreover, in the FSI simulation resolved turbulence scales interacting with moving and deforming rubber immersed in the subcritical Reynolds number-turbulent flow are successfully captured by the hybrid modelling technique coupled with a structural solver under the coupling procedure of an implicit partitioned approach. Similar with earlier studies with different scale-resolving proposals on the same FSI case, a periodic oscillating motion of the rubber that is produced from a phase-averaging method is also demonstrated in this present investigation. Nevertheless, a non-physical deformation of the rubber in the spanwise direction occurs. The new FSI result is evaluated with existing results from earlier works as a pivotal basis for further researches, such as implementations of new mesh stiffness model and filter width.

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Model Development for Fluid Structure Interaction in the Slip Regime

ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels: Parts A and B ◽

10.1115/fedsm-icnmm2010-31277 ◽

2010 ◽

Author(s):

Jennifer van Rij ◽

Todd Harman ◽

Tim Ameel

Keyword(s):

Energy Exchange ◽

Temperature Jump ◽

Slip Flow ◽

Model Development ◽

Fluid Structure Interaction ◽

Solid Surfaces ◽

Fluid Structure ◽

Structure Interaction ◽

First Order ◽

Slip Regime

While many microscale systems are subject to both rarefaction and fluid-structure-interaction (FSI) effects, most commercial algorithms cannot model both, if either, of these for general applications. This study modifies the momentum and thermal energy exchange models of an existing, continuum based, multifield, compressible, unsteady, Eulerian-Lagrangian FSI algorithm, such that the equivalent of first-order slip velocity and temperature jump boundary conditions are achieved at fluid-solid surfaces, which may move with time. Following the development and implementation of the slip flow momentum and energy exchange models, several basic configurations are considered and compared to established data to verify the resulting algorithm’s capabilities.

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An Improved FE-BE Method for Solving the Fluid-Structure Interaction Problems of Plates

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.627.84 ◽

2014 ◽

Vol 627 ◽

pp. 84-88

Author(s):

Zhen Wei Huang ◽

Qi Dou Zhou

Keyword(s):

Fluid Structure Interaction ◽

Numerical Approach ◽

Numerical Results ◽

Thin Plates ◽

Fe Method ◽

Exterior Region ◽

Fluid Structure ◽

Structure Interaction ◽

Interaction Equation ◽

Inner Region

This paper proposed a numerical approach called improved FE-BE (finite element-boundary element) method to solve the fluid-structure interaction problems of plate-like systems. In order to avoid the mesh of both faces of the thin plates, some dumb structures were added to make the plate systems closed. Thus the conventional FE-BE method can be adopted to solve this problem. The dynamic response equation of the inner region can be obtained by the FE method, and the acoustic added mass and damping coefficients of the exterior region can be obtained by the BE method. Then the final fluid-structure interaction equation can be easily solved. Numerical results of some examples are computed to demonstrate the validation of the present method. The comparison of numerical results and reference solutions shows that the proposed method is acceptable for solving the fluid-structure interaction of plates.

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