Coupling Computational Fluid Dynamics with 6DOF Rigid Body Dynamics for Unsteady, Accelerated Flow Simulations

The shape of hypersonic aircrafts represented by waveriders is becoming more slender and flatter, thereby greatly reducing the structural rigidity. This innovation is applied to satisfy the demand of long-range flight. The rolling stability of the waveriders is poor due to the slender shape. Therefore, the effect of the elastic deformation on the rolling stability cannot be ignored. The effect of the elastic deformation on the stability of rolling and forced pitching/free rolling coupling motions of the waveriders is studied through computational fluid dynamics (CFD)/computational structural dynamics (CSD)/rigid body dynamics (RBD) coupling methodology. Comparison results of numerical simulation indicate that the elastic deformation of the structure increases the local angle of attack, thereby enhancing the static stability of the waveriders. The rolling motion of the waveriders changes from point attractor to periodic attractor when the vibration velocity due to elastic deformation is considered. The rolling oscillation frequency of the flexible model is higher than that of the rigid model. For the forced pitching/free rolling motion, stability theory based on the rigid body hypothesis is unsuitable when the elastic effect is taken into consideration.

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A Computational Tool For Unsteady Aerodynamic Flow Simulations Coupled With Rigid Body Dynamics And Control

30th AIAA Applied Aerodynamics Conference ◽

10.2514/6.2012-3034 ◽

2012 ◽

Author(s):

Jonathan Camargo ◽

Omar Lopez ◽

Nicolas Ochoa-Lleras

Keyword(s):

Rigid Body ◽

Rigid Body Dynamics ◽

Computational Tool ◽

Flow Simulations ◽

Unsteady Aerodynamic ◽

Body Dynamics ◽

Dynamics And Control ◽

And Control

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Slipping–rolling transitions of a body with two contact points

Nonlinear Dynamics ◽

10.1007/s11071-021-06538-5 ◽

2021 ◽

Author(s):

Mate Antali ◽

Gabor Stepan

Keyword(s):

Rigid Body ◽

Contact Point ◽

Static Friction ◽

Rigid Body Dynamics ◽

Contact Forces ◽

Friction Forces ◽

Contact Points ◽

Body Dynamics ◽

Coulomb Model ◽

Rigid Surfaces

AbstractIn this paper, the general kinematics and dynamics of a rigid body is analysed, which is in contact with two rigid surfaces in the presence of dry friction. Due to the rolling or slipping state at each contact point, four kinematic scenarios occur. In the two-point rolling case, the contact forces are undetermined; consequently, the condition of the static friction forces cannot be checked from the Coulomb model to decide whether two-point rolling is possible. However, this issue can be resolved within the scope of rigid body dynamics by analysing the nonsmooth vector field of the system at the possible transitions between slipping and rolling. Based on the concept of limit directions of codimension-2 discontinuities, a method is presented to determine the conditions when the two-point rolling is realizable without slipping.

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