Model Development for Fluid Structure Interaction in the Slip Regime

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.

Fluid–Structure Interaction Simulation on Energy Harvesting From Vortical Flows by a Passive Heaving Foil

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Zhenglun Alan Wei ◽  
Zhongquan Charlie Zheng
Keyword(s):  
Energy Harvesting ◽  
Fluid Structure Interaction ◽  
Time Integration ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Periodic Response ◽  
Structure Interaction ◽  
First Order ◽  
Interaction Simulation ◽  
Ib Method

This study investigates energy harvesting of a two-dimensional foil in the wake downstream of a cylinder. The foil is passively mobile in the transverse direction. An immersed boundary (IB) method with a fluid–structure interaction (FSI) model is validated and employed to carry out the numerical simulation. For improving numerical stability, this study incorporates a modified low-storage first-order Runge–Kutta scheme for time integration and demonstrates the performance of this temporal scheme on reducing spurious pressure oscillations of the IB method. The simulation shows the foil emerged in a vortical wake achieves better energy harvesting performance than that in a uniform flow. The types of the dynamic response of the energy harvester are identified, and the periodic response is desired for optimal energy harvesting performance. Last, the properties of vortical wakes are found to be of pivotal importance in obtaining this desired periodic response.

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

2008 ◽  
Vol 22 (06) ◽  
pp. 651-669 ◽  
Author(s):  
LIXIANG ZHANG ◽  
WENQUAN WANG ◽  
YAKUN GUO
Keyword(s):  
Energy Exchange ◽  
Fluid Structure Interaction ◽  
Frictional Coefficient ◽  
Energy Deficit ◽  
Wall Region ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Flow Features ◽  
Inner Region ◽  
Near Wall

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.

scholarly journals Experimental Characterization of High-Amplitude Fluid–Structure Interaction of a Flexible Hydrofoil at High Reynolds Number

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Brian R. Elbing ◽  
Steven D. Young ◽  
Michael L. Jonson ◽  
Robert L. Campbell ◽  
Brent A. Craven ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Model Development ◽  
Fluid Structure Interaction ◽  
Low Frequency ◽  
High Amplitude ◽  
Cylinder Wake ◽  
Constraint Forces ◽  
Fluid Structure ◽  
Structure Interaction ◽  
High Reynolds

Abstract A fluid–structure interaction (FSI) experiment was performed to study low-frequency (∼10 Hz), high-amplitude (±3.5% of the span) fin motion. This was achieved by placing an Inconel swept-fin at −9.6 deg angle-of-attack within the wake of a roughened cylinder. Speeds between 2.5 and 3.6 m/s produced cylinder diameter-based Reynolds numbers between 190,000 and 280,000, respectively. Detailed descriptions of the geometry, material/structural behavior, fluid properties, and initial conditions are provided to facilitate computational model development. Given the initial conditions, the resulting forced fin behavior was characterized with measurements of the mean and fluctuating velocity upstream of the fin (i.e., within the cylinder wake), fin tip/surface motion, and fin constraint forces/moments. This work provides a detailed experimental dataset of conditions mimicking a crashback event that is also a challenging FSI benchmark problem involving turbulent, vortex-induced structure motion. It has been used as a validation condition for FSI simulations, and it can be used to validate other FSI models as well as identifying strengths and weaknesses of various modeling approaches.

Microtube Gas Flows With Second-Order Slip Flow and Temperature Jump Boundary Conditions

2006 ◽  
Author(s):  
Nian Xiao ◽  
John Elsnab ◽  
Tim Ameel
Keyword(s):  
Nusselt Number ◽  
Boundary Conditions ◽  
Temperature Jump ◽  
Order Approximation ◽  
Slip Flow ◽  
Order Effect ◽  
Second Order ◽  
First Order ◽  
Slip Regime ◽  
Energy Equations

Second-order slip flow and temperature jump boundary conditions are applied to solve the momentum and energy equations in a microtube for an isoflux thermal boundary condition. The flow is assumed to be hydrodynamically fully developed, and the thermal field is either fully developed or developing from the tube entrance. In general, first-order boundary conditions are found to over predict the effects of slip and temperature jump, while the effect of the second-order terms is most significant at the upper limit of the slip regime. The second-order terms are found to provide a correction to the first-order approximation. For airflows, the maximum second-order correction to the Nusselt number is on the order of 50%. The second-order effect is also more significant in the entrance region of the tube. Nusselt numbers are found to increase relative to their no-slip values when temperature jump effects are small. In cases where slip and temperature jump effects are of the same order, or where temperature jump effects dominate, the Nusselt number decreases when compared to traditional no-slip conditions.

scholarly journals A partitioned numerical scheme for fluid-structure interaction with slip

2020 ◽  
Author(s):  
Martina Bukac ◽  
Suncica Canic
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Slip Rate ◽  
Rates Of Convergence ◽  
Energy Estimates ◽  
Fluid Viscosity ◽  
Coupling Condition ◽  
Fluid Structure ◽  
Structure Interaction ◽  
First Order

We present a loosely coupled, partitioned scheme for fluid-structure interaction problems with the Navier slip boundary condition. The fluid flow is modeled by the Navier-Stokes equations for an incompressible, viscous fluid, interacting with a thin elastic structure modeled by the membrane or Koiter shell type equations. The fluid and structure are coupled via two sets of coupling conditions: a dynamic coupling condition describing balance of forces, and a kinematic coupling condition describing fluid slipping tangentially to the moving fluid-structure interface, with no penetration in the normal direction. We propose a novel, efficient partitioned scheme where the fluid sub-problem is solved separately from the structure sub-problem, and there is no need for sub-iterations to achieve stability, convergence, and its optimal, first-order accuracy. We derive energy estimates, which prove that the proposed scheme is unconditionally stable, and present convergence analysis which shows that the method is first-order accurate in time and optimally convergent in space. The theoretical rates of convergence in time are confirmed numerically on an example with an explicit solution using the method of manufactured solutions. The effects of the slip rate and fluid viscosity on the FSI solution are numerically investigated in two additional examples.

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