Numerical Simulation of Unsteady Aerodynamic Loads over an Aircraft

The unsteady aerodynamic loads are the basic of the aeroelastic. This paper focuses on the computation of the unsteady aerodynamic loads for forced periodic motions under different Mach numbers. The flow is modeled using the Euler equations and an unsteady time-domain solver is used for the computation of aerodynamic loads for forced periodic motions. The Euler equations are discretized on curvilinear multi-block body conforming girds using a cell-centred finite volume method. The implicit dual-time method proposed by Jameson is used for time-accurate calculations. Rigid body motions were treated by moving the mesh rigidly in response to the applied sinusoidal motion. For an aircraft model, a validation of the unsteady aerodynamics loads is first considered. Furthermore, a study for understanding the influence of different Mach number was conducted. A reverse of the trend of hysteretic loops can be observed with the increasing of the Mach number.

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Numerical Simulation of Unsteady Aerodynamic Loads over an Aerofoil in Transonic Flow

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.644.275 ◽

2013 ◽

Vol 644 ◽

pp. 275-278 ◽

Cited By ~ 1

Author(s):

Yu Qian ◽

Jun Li Yang ◽

Xiao Jun Xiang ◽

Ming Qiang Chen

Keyword(s):

Mach Number ◽

Euler Equations ◽

Unsteady Aerodynamics ◽

Angle Of Incidence ◽

Periodic Motions ◽

Aerodynamic Loads ◽

Unsteady Aerodynamic ◽

Reduced Frequency ◽

Sinusoidal Motion ◽

Naca 0012

The unsteady aerodynamic loads are the basic of the aeroelasitc. This paper focuses on the computation of the unsteady aerodynamic loads for forced periodic motions under high subsonic Mach numbers. The flow is modeled using the Euler equations and an unsteady time-domain solver is used for the computation of aerodynamic loads for forced periodic motions. The Euler equations are discretized on curvilinear multi-block body conforming girds using a cell-centred finite volume method. The implicit dual-time method proposed by Jameson is used for time-accurate calculations. Rigid body motions were treated by moving the mesh rigidly in response to the applied sinusoidal motion. For NACA 0012 airfoil, a validation of the unsteady aerodynamics loads is first considered. Furthermore, a study for understanding the influence of motion parameters, the Mach number, mean angle of incidence, reduced frequency, amplitude, was also conducted. A reverse of the trend of hysteretic loops can be observed with the increasing of the Mach number. Nonlinear hysteretic loops are turned up when increasing the amplitude and the reduced frequency during the applied pitch sinusoidal motion.

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Coupled analysis of the unsteady aerodynamics and multi-body dynamics of a small car overtaking a coach

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407019831559 ◽

2019 ◽

Vol 233 (14) ◽

pp. 3684-3699 ◽

Cited By ~ 1

Author(s):

Jun Liu ◽

Zhengqi Gu ◽

Taiming Huang ◽

Shuya Li ◽

Ledian Zheng ◽

...

Keyword(s):

Adverse Effect ◽

Unsteady Aerodynamics ◽

Coupled Analysis ◽

Detached Eddy Simulation ◽

Aerodynamic Loads ◽

Unsteady Aerodynamic ◽

Eddy Simulation ◽

Body Dynamics ◽

Vehicle Motion ◽

Multi Body

The severe additional aerodynamic loads that are generated on a small car when overtaking a coach have an adverse effect on the car handling stability and its safety. In this article, a two-way coupling of the unsteady aerodynamics and multi-body dynamics is performed in order to study the mutual interactions of a car in an overtaking maneuver with a coach. The unsteady aerodynamic interactions are obtained by using SST (Menter) K-Omega Detached Eddy Simulation and overset mesh technology. The aerodynamics couple the multi-body dynamics, taking into account the effects of the transverse spacing and the cross winds. To validate the necessity of the two-way coupling method, a one-way coupling of the aerodynamics to the vehicle motion is also conducted. Finally, by comparing the aerodynamic loads and the dynamic response of the overtaking car in different overtaking maneuvers between one- and two-way coupling, the results show that it should be considered with two-way coupling analyses of the car while overtaking a coach, particularly under the severe conditions of a lower transverse spacing or the crosswinds.

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A Comparative Study of Two Preconditioners for Solving 3D Inviscid Low Speed Flows

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.423 ◽

2011 ◽

Vol 110-116 ◽

pp. 423-430 ◽

Cited By ~ 1

Author(s):

Kazem Hejranfar ◽

Ramin Kamali Moghadam

Keyword(s):

Mach Number ◽

Comparative Study ◽

Euler Equations ◽

Finite Volume ◽

Eigenvalues And Eigenvectors ◽

Flow Solver ◽

Low Mach Number ◽

Euler Flow ◽

A Cell ◽

And Performance

In the present study, two preconditioners proposed by Eriksson, and Choi and Merkel are implemented on a 3D upwind Euler flow solver on unstructured meshes. The mathematical formulations of these preconditioning schemes for the set of primitive variables are drawn and their eigenvalues and eigenvectors are compared with each others. A cell-centered finite volume Roe's method is used for discretization of the 3D preconditioned Euler equations. The accuracy and performance of these preconditioning schemes are examined by computing low Mach number flows over the ONERA M6 wing for different conditions.

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Computation of three-dimensional transonic flow using a cell vertex finite volume method for the Euler equations

Acta Mechanica ◽

10.1007/bf01187436 ◽

1996 ◽

Vol 115 (1-4) ◽

pp. 161-177 ◽

Cited By ~ 3

Author(s):

S. K. Chakrabartyy ◽

K. Dhanalakshmi ◽

J. S. Mathur

Keyword(s):

Finite Volume Method ◽

Euler Equations ◽

Finite Volume ◽

Transonic Flow ◽

Three Dimensional ◽

A Cell ◽

Volume Method

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Prediction of unsteady aerodynamic loads in cascades using the linearized Euler equations on deforming grids

10.2514/6.1991-3378 ◽

1991 ◽

Cited By ~ 6

Author(s):

KENNETH HALL ◽

WILLIAM CLARK

Keyword(s):

Euler Equations ◽

Aerodynamic Loads ◽

Linearized Euler Equations ◽

Unsteady Aerodynamic

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Advanced Ducted Engines: Impact of Unsteady Aerodynamics on Fan Vibration Properties

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education ◽

10.1115/92-gt-228 ◽

1992 ◽

Author(s):

Arno H. Klose

Keyword(s):

Mode Coupling ◽

Unsteady Aerodynamics ◽

Light Weight ◽

Aeroelastic Stability ◽

Resonant Frequencies ◽

Aerodynamic Loads ◽

Reinforced Plastics ◽

Unsteady Aerodynamic ◽

Vibration Properties ◽

Carbon Fibre Reinforced Plastics

Fans of Advanced Ducted Engines (ADE) will be built from light-weight materials such as carbon-fibre-reinforced plastics (CFRP). Due to their low density, the aeroelastic behaviour of these fan blades is significantly different from that of conventional titanium fan blading. Calculations performed during the design of ADE fan bladings show that self-induced aerodynamic loads can significantly alter the resonant frequencies; furthermore, aerodynamic coupling of the different in-vacuo eigenmodes can occur. This is not the case for conventional titanium fan blading, where the vibration properties are largely unaffected by unsteady aerodynamic forces. It is concluded that for light-weight fan blading, it is necessary to take into account aerodynamic stiffening and aerodynamic mode coupling when computing eigenfrequencies and aeroelastic stability.

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