scholarly journals Inflatable Leading Edge-Based Dynamic Stall Control considering Fluid-Structure Interaction

2020 ◽  
Vol 2020 ◽  
pp. 1-28
Author(s):  
Shi-Long Xing ◽  
He-Yong Xu ◽  
Ming-Sheng Ma ◽  
Zheng-Yin Ye
Keyword(s):  
Lift Coefficient ◽  
Fluid Structure Interaction ◽  
Leading Edge ◽  
Dynamic Stall ◽  
Elastic Membrane ◽  
Radius Of Curvature ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Stall Control

The inflatable leading edge (ILE) is explored as a dynamic stall control concept. A fluid-structure interaction (FSI) numerical method for the elastic membrane structure is constructed based on unsteady Reynolds-averaged Navier-Stokes (URANS) and a mass-spring-damper (MSD) structural dynamic model. Radial basis function- (RBF-) based mesh deformation algorithm and Laplacian and optimization-based mesh smoothing algorithm are adopted in flowfield simulations to achieve the pitching oscillation of the airfoil and to ensure the mesh quality. An airfoil is considered at a freestream Mach number of 0.3 and chord-based Reynolds number of 3.92×106. The airfoil is pitched about its quarter-chord axis at a sinusoidal motion. The numerical results indicate that the ILE can change the radius of curvature of the airfoil leading edge, which could reduce the streamwise adverse pressure gradient and suppress the formation of dynamic stall vortex (DSV). Although the maximum lift coefficient of the airfoil is slightly reduced during the control process, the maximum drag and pitching moment coefficients of the airfoil are greatly reduced by up to 66% and 75.2%, respectively. The relative position of the ILE has a significant influence on its control effect. The control laws of inflation and deflation also affect the control ability of the ILE.

Dynamic stall control using inflatable leading edge

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040108 ◽  
Author(s):  
Shi-Long Xing ◽  
He-Yong Xu ◽  
Zheng-Yin Ye ◽  
Ming-Sheng Ma ◽  
Yue Xu
Keyword(s):  
Lift Coefficient ◽  
Leading Edge ◽  
Adverse Pressure Gradient ◽  
Rotor Blades ◽  
Dynamic Stall ◽  
Elastic Membrane ◽  
Radius Of Curvature ◽  
Structural Dynamic ◽  
Pitching Airfoil ◽  
Stall Control

The inflatable leading edge (ILE) as a dynamic stall control concept for helicopter rotor blades was investigated numerically on a dynamically pitching airfoil. A fluid–structure interaction (FSI) numerical method for the elastic membrane structure was constructed based on unsteady Reynolds-averaged Navier–Stokes (URANS) equations and mass spring damper (MSD) structural dynamic model. The numerical results indicate that the ILE can change the radius of curvature of the airfoil leading edge, which could reduce the streamwise adverse pressure gradient and suppress the formation of dynamic stall vortex (DSV). Although the maximum lift coefficient of the airfoil is reduced by 8.2%, the maximum drag and pitching moment coefficients of the airfoil are reduced by up to 50.1% and 55.3%, respectively.

scholarly journals Linear Stability Analysis and Validation of a Unified Solution Method for Fluid-Structure-Interaction on Structural Dynamic Problems

2005 ◽  
Author(s):  
C. G. Giannopapa ◽  
G. Papadakis
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Solution Method ◽  
Fluid Structure Interaction ◽  
Analytic Solutions ◽  
Computational Domain ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction

In the conventional approach for fluid-structure interaction problems, the fluid and solid components are treated separately and information is exchanged across their interface. According to the conventional terminology, the current numerical methods can be grouped in two major categories: Partitioned methods and monolithic methods. Both methods use two separate sets of equations for fluid and solid. A unified solution method has been presented [1], which is different from these methods. The new method treats both fluid and solid as a single continuum, thus the whole computational domain is treated as one entity discretised on a single grid. Its behavior is described by a single set of equations, which are solved fully implicitly. In this paper, 2 time marching and one spatial discretisation scheme, widely used for fluids’ equations, are applied for the solution of the equations for solids. Using linear stability analysis, the accuracy and dissipation characteristics of the resulting difference equations are examined. The aforementioned schemes are applied to a transient structural problem (beam bending) and the results compare favorably with available analytic solutions and are consistent with the conclusions of the stability analysis. A parametric investigation using different meshes, time steps and beam sizes is also presented. For all cases examined the numerical solution was stable and robust and proved to be suitable for the next stage of application to full fluid-structure interaction problems.

Experimental analysis of fluid-structure interaction in flexible wings at low Reynolds number flows

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mustafa Serdar Genç ◽  
Hacımurat Demir ◽  
Mustafa Özden ◽  
Tuna Murat Bodur
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Fluid Structure Interaction ◽  
Leading Edge ◽  
Flexible Wings ◽  
Flexible Membrane ◽  
Fluid Structure ◽  
Content Type ◽  
Structure Interaction ◽  
Membrane Deformations

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.

Numerical Investigation of Hydroelastic Response of a Three-Dimensional Deformable Hydrofoil

2020 ◽  
Author(s):  
Saeed Hosseinzadeh ◽  
Kristjan Tabri
Keyword(s):  
Pressure Coefficient ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Leading Edge ◽  
Elastic Response ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Lift And Drag ◽  
Hydroelastic Response

The present study is concerned with the numerical simulation of Fluid-Structure Interaction (FSI) on a deformable three-dimensional hydrofoil in a turbulent flow. The aim of this work is to develop a strongly coupled two-way fluid-structure interaction methodology with a sufficiently high spatial accuracy to examine the effect of turbulent and cavitating flow on the hydroelastic response of a flexible hydrofoil. A 3-D cantilevered hydrofoil with two degrees-of-freedom is considered to simulate the plunging and pitching motion at the foil tip due to bending and twisting deformation. The defined problem is numerically investigated by coupled Finite Volume Method (FVM) and Finite Element Method (FEM) under a two-way coupling method. In order to find a better understanding of the dynamic FSI response and stability of flexible lifting bodies, the fluid flow is modeled in the different turbulence models and cavitation conditions. The flow-induced deformation and elastic response of both rigid and flexible hydrofoils at various angles of attack are studied. The effect of three-dimension body, pressure coefficient at different locations of the hydrofoil, leading-edge and trailing-edge deformation are presented and the results show that because of elastic deformation, the angle of attack increases and it lead to higher lift and drag coefficients. In addition, the deformations are generally limited by stall condition and because of unsteady vortex shedding, the post-stall condition should be considered in FSI simulation of deformable hydrofoil. To evaluate the accuracy of the numerical model, the present results are compared and validated against published experimental data and showed good agreement.

A Qualified Method for Fluid-Structure Interaction in Piping Design

2006 ◽  
Author(s):  
Miks Hartmann
Keyword(s):  
Fluid Structure Interaction ◽  
Substantial Contribution ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Forces ◽  
Various Boundary Conditions ◽  
Coupled Calculation ◽  
Piping Systems ◽  
Hydraulic Load

In piping design hydraulic load cases and the resulting dynamic structural loads are induced and generated by strongly time dependent pressure surges and subsequent oscillations. Therefore, with liquid filled piping, the implementation of fluid-structure interaction by coupling the fluiddynamic and the structural dynamic codes gives a substantial contribution to more realistic loading results. Considering this effect, usually a load reduction due to energy losses and the phase and frequency shift from fluid to structure and vice versa is achieved. In cases of fluid structure resonance the results are more reliable and can help to develop an optimized support concept. To realize the coupled calculation of both codes they are bundled by a special user environment, where the coupling points are specified and marked. We describe the input of fluid forces at those points and the treatment of the liquid masses inside the piping, as well as the method of back-coupling the resulting structural displacements into the fluid calculation. The method was validated against measurements of load cases in power plant piping systems and experimental results for various boundary conditions. The most realistic results were obtained by combining the coupling with the application of dynamic friction in the fluid code.

Fluid-Structure Interaction With S-TRAC and KWUROHR Due to Pressure Waves

2003 ◽  
Author(s):  
Ulrich Neumann
Keyword(s):  
Fluid Structure Interaction ◽  
Dynamic Program ◽  
Pressure Waves ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Forces ◽  
Piping Systems

In the last years we have spent a lot of time to improve our programs and procedures, especially on the field of fluiddynamic investigations in piping systems. To get the best design of piping layout the results of fluiddynamic and structural calculations should be realistic as far as possible. In this connection a very important effect is the fluid-structure interaction (FSI) which we have implemented in S-TRAC in connection with our structural dynamic program KWUROHR. On the basis of different calculations we will show the influence of the coupling on the fluid forces and the piping layout.

Modal Test of Scaled-Down Reactor Internals in SMART Considering the Fluid-Structure Interaction

2011 ◽  
Author(s):  
Seungho Lim ◽  
Kyungrok Ha ◽  
Kyoung-Su Park ◽  
No-Cheol Park ◽  
Young-Pil Park ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Seismic Analysis ◽  
Fluid Structure Interaction ◽  
Mass Effect ◽  
Mode Shapes ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Standard Design ◽  
Reactor Internals

The System-integrated Modular Advanced ReacTor (SMART) is a small modular integral-type reactor for the seawater desalination and small-scaled power generation under development in Korea. Although the SMART is innovative reactor with a sensible mixture of the proven technology and advanced design features aimed at enhanced safety, there is no valid prototype which can specify the structural dynamic characteristics of reactor internals. Thus, extensive research for the technology verification and standard design approval are in progress. One of them is to perform the dynamic characteristics identification of reactor internals. Especially, it is focused on the added mass effect caused by the fluid-structure interaction because the reactor internals is submerged in the reactor coolant. The extracted dynamic characteristics such as the natural frequencies and the vibratory mode shapes can be used as the basis on further dynamic analysis, for example, seismic analysis and a postulated pipe break analysis.

Numerical investigation of flexible flapping wings using computational fluid dynamics/computational structural dynamics method

2016 ◽  
Vol 232 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Long Liu ◽  
Hongda Li ◽  
Haisong Ang ◽  
Tianhang Xiao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Structural Dynamics ◽  
Fluid Structure Interaction ◽  
Flapping Wings ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Non Linear ◽  
Computational Structural Dynamics

A fluid–structure interaction numerical simulation was performed to investigate the flow field around a flexible flapping wing using an in-house developed computational fluid dynamics/computational structural dynamics solver. The three-dimensional (3D) fluid–structure interaction of the flapping locomotion was predicted by loosely coupling preconditioned Navier–Stokes solutions and non-linear co-rotational structural solutions. The computational structural dynamic solver was specifically developed for highly flexible flapping wings by considering large geometric non-linear characteristics. The high fidelity of the developed methodology was validated by benchmark tests. Then, an analysis of flexible flapping wings was carried out with a specific focus on the unsteady aerodynamic mechanisms and effects of flexion on flexible flapping wings. Results demonstrate that the flexion will introduce different flow fields, and thus vary thrust generation and pressure distribution significantly. In the meanwhile, relationship between flapping frequency and flexion plays an important role on efficiency. Therefore, appropriate combination of frequency and flexion of flexible flapping wings provides higher efficiency. This study may give instruction for further design of flexible flapping wings.

Numerical Investigations of the Long Blade Performance Using RANS Solution and FEA Method Coupled With One-Way and Two-Way Fluid-Structure Interaction Models

2017 ◽  
Author(s):  
Minyan Yin ◽  
Jun Li ◽  
Liming Song ◽  
Zhenping Feng
Keyword(s):  
Rotor Blade ◽  
Mechanical Performance ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Leading Edge ◽  
Von Mises Stress ◽  
Maximum Displacement ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Von Mises

The aerodynamic and mechanical performance of the last stage was numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes (RANS) solution and Finite Element Analysis (FEA) coupled with the one-way and two-way fluid-structure interaction models in this work. The part-span damping snubber and tip damping shroud of the rotor blade and aerodynamic pressure on rotor blade mechanical performance was considered in the one-way model. The two-way fluid-structure interaction model coupled with the mesh deformation technology was conducted to analyze the aerodynamic and mechanical performance of the last stage rotor blade. One-way fluid-structure interaction model numerical results show that the location of nodal maximum displacement moves from leading edge of 85% blade span to the trailing edge of 85% blade span. The position of nodal maximum Von Mises stress is still located at the first tooth upper surface near the leading edge at the blade root of pressure side. The two-way fluid-structure interaction model results show that the variation of static pressure distribution on long blade surface is mostly concentrated at upper region, absolute outflow angle of long blade between the 40% span and 95% span reduces, the location of nodal maximum displacement appears at the trailing edge of 85% blade span. Furthermore, the position of nodal maximum Von Mises stress remains the same and the value decreases compared to the oneway fluid-structure model results.

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