scholarly journals Computational-Fluid-Dynamics- and Computational-Structural-Dynamics-Based Time-Accurate Aeroelasticity of Helicopter Rotor Blades

2010 ◽  
Vol 47 (3) ◽  
pp. 858-863 ◽  
Author(s):  
G. P. Guruswamy
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Structural Dynamics ◽  
Rotor Blades ◽  
Helicopter Rotor ◽  
Helicopter Rotor Blades ◽  
Computational Structural Dynamics

Optimization of Biomimetic Propulsive Kinematics of a Flexible Foil Using Integrated Computational Fluid Dynamics–Computational Structural Dynamics Simulations

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
Jiho You ◽  
Jinmo Lee ◽  
Seungpyo Hong ◽  
Donghyun You
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Young’S Modulus ◽  
Phase Angle ◽  
Structural Dynamics ◽  
Stokes Equations ◽  
Young's Modulus ◽  
Immersed Boundary ◽  
Computational Structural Dynamics ◽  
Dynamics Simulations

A computational methodology, which combines a computational fluid dynamics (CFD) technique and a computational structural dynamics (CSD) technique, is employed to design a deformable foil whose kinematics is inspired by the propulsive motion of the fin or the tail of a fish or a cetacean. The unsteady incompressible Navier–Stokes equations are solved using a second-order accurate finite difference method and an immersed-boundary method to effectively impose boundary conditions on complex moving boundaries. A finite element-based structural dynamics solver is employed to compute the deformation of the foil due to interaction with fluid. The integrated CFD–CSD simulation capability is coupled with a surrogate management framework (SMF) for nongradient-based multivariable optimization in order to optimize flapping kinematics and flexibility of the foil. The flapping kinematics is manipulated for a rigid nondeforming foil through the pitching amplitude and the phase angle between heaving and pitching motions. The flexibility is additionally controlled for a flexible deforming foil through the selection of material with a range of Young's modulus. A parametric analysis with respect to pitching amplitude, phase angle, and Young's modulus on propulsion efficiency is presented at Reynolds number of 1100 for the NACA 0012 airfoil.

Computational Fluid Dynamics–Computational Structural Dynamics Rotor Coupling Using an Unstructured Reynolds-Averaged Navier–Stokes Methodology

2012 ◽  
Vol 57 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Jennifer N. Abras ◽  
C. Eric Lynch ◽  
Marilyn J. Smith
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Structural Dynamics ◽  
Flight Test ◽  
Navier Stokes ◽  
Structured Grid ◽  
Direct Contrast ◽  
Computational Structural Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Grid Points

The focus of this paper is to discuss the unique challenges introduced through the use of unstructured grids in rotorcraft computational fluid dynamics (CFD)–computational structural dynamics (CSD) coupling. The use of unstructured grid methodology in CFD has been expanding because of the advantages in grid generation and modeling of complex configurations. However, the resulting amorphous distribution of the grid points on the rotor blade surface provides no information with regard to the orientation of the blade, in direct contrast to structured grid methodology that can take advantage of the ordered mapping of points to identify the orientation as well as simplifying airloads integration. A methodology has been developed and is described here, which now permits unstructured methods to be utilized for elastic rotary-wing simulations. This methodology is evaluated through comparison of the UH60A rotor with available flight test data for forward flight.

Prediction of Helicopter Rotor Loads Using Time-Spectral Computational Fluid Dynamics and an Exact Fluid–Structure Interface

2011 ◽  
Vol 56 (4) ◽  
pp. 1-15 ◽  
Author(s):  
Seongim Choi ◽  
Anubhav Datta ◽  
Juan J. Alonso
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamic Stall ◽  
Helicopter Rotor ◽  
Fluid Structure ◽  
Blade Shape ◽  
Coupling Procedure ◽  
Time Marching ◽  
Computational Structural Dynamics ◽  
Computational Fluid Dynamics Cfd

The objectives of this paper are to introduce time-spectral computational fluid dynamics (CFD) for the analysis of helicopter rotor flows in level flight and to introduce an exact fluid–structure interface for coupled CFD/computational structural dynamics (CSD) analysis. The accuracy and efficiency of time-spectral CFD are compared with conventional time-marching computations. The exact interface is equipped with an exact delta coupling procedure that bypasses the requirement for sectional airloads. Predicted loads are compared between time-spectral and time-marching CFD using both interfaces and validated using UH-60A flight data for high-vibration and dynamic stall conditions. It is concluded that time-spectral CFD can indeed predict rotor performance and peak-to-peak structural loads efficiently, and hence, open opportunity for blade shape optimization. The vibratory and dynamic stall loads, however, require a large number of time instances, which reduces its efficiency. The exact interface and delta procedure allow coupling to be implemented for arbitrary grids and advanced structural models exactly, without the requirement for two-dimensional sectional airloads.

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.

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