Fully Nonlinear Model of Cables

AIAA Journal ◽  
1992 ◽  
Vol 30 (12) ◽  
pp. 2993-2996 ◽  
Author(s):  
Perngjin F. Pai ◽  
Ali H. Nayfeh
Keyword(s):  
Nonlinear Model ◽  
Fully Nonlinear

Studying the Effect of Freeplay on Nose Landing Gear Shimmy Using a Fully Nonlinear Model

2018 ◽  
Author(s):  
Mohsen Rahmani ◽  
Kamran Behdinan
Keyword(s):  
Nonlinear Model ◽  
Nonlinear Stability ◽  
Dynamic Models ◽  
Landing Gear ◽  
Stability Boundaries ◽  
Fully Nonlinear ◽  
Freeplay Nonlinearity ◽  
Stability Maps ◽  
Long Time ◽  
Time Histories

Shimmy is a common instability of landing gear systems which has been known for a long time. Yet, it is often studied using simplified dynamic models in which the chief system nonlinearities are neglected. Particularly, the influence of worn components and loose joints manifesting itself as a freeplay nonlinearity has been only touched upon in few works. The present paper utilizes a fully nonlinear landing gear dynamic model to obtain nonlinear stability boundaries and to study the onset, severity, frequency jumps, and mode shifts of the system as a result of the torque link freeplay. Using stability maps in the parameter space and time histories of the oscillations the degrading effect of excessive clearance and wear in the torque links is demonstrated, which in turn offers insights for designing shimmy-free landing gears.

A fully nonlinear model for sloshing in a rotating container

2000 ◽  
Vol 27 (1) ◽  
pp. 23-52 ◽  
Author(s):  
Michele La Rocca ◽  
Giampiero Sciortino ◽  
Maria Antonietta Boniforti
Keyword(s):  
Nonlinear Model ◽  
Fully Nonlinear

Some Nonlinear Behaviour of Freak Waves and Envelope Solitons

2002 ◽  
Author(s):  
Didier Clamond ◽  
John Grue
Keyword(s):  
Time Evolution ◽  
Nonlinear Model ◽  
Nonlinear Behaviour ◽  
Freak Waves ◽  
Fully Nonlinear ◽  
Weakly Nonlinear ◽  
Envelope Solitons ◽  
Long Time ◽  
Long Time Evolution ◽  
The Right

The nonlinear Schro¨dinger-like equations are widly used models for investigating the evolution of surface gravity waves with narrow-banded spectra. We numerically compare one of these simplified models with a fully nonlinear one. In particular, we study the long time evolution of wave groups. Although the simplified model predicts the right number of soliton formed, their behaviour and long time evolution is not well described. Solitons interact differently with the two models. During the interaction, freak waves are formed. Their occurence is more frequent with the fully nonlinear model. A more interesting phenomemon is, during the formation of freak waves, the wave envelope oscillates rapidly. This “intermittence” is not at all predicted by any weakly nonlinear model.

Fully Nonlinear Model for Water Wave Propagation from Deep to Shallow Waters

2012 ◽  
Vol 138 (5) ◽  
pp. 362-371 ◽  
Author(s):  
A. Galan ◽  
G. Simarro ◽  
A. Orfila ◽  
J. Simarro ◽  
P. L.-F. Liu
Keyword(s):  
Wave Propagation ◽  
Nonlinear Model ◽  
Water Wave ◽  
Shallow Waters ◽  
Fully Nonlinear

scholarly journals Interactions of Coherent Structures on the Surface of Deep Water

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 83 ◽  
Author(s):  
Dmitry Kachulin ◽  
Alexander Dyachenko ◽  
Andrey Gelash
Keyword(s):  
Nonlinear Model ◽  
Deep Water ◽  
Relative Phase ◽  
Initial Conditions ◽  
Wave Interaction ◽  
Ideal Incompressible Fluid ◽  
Interaction Coefficient ◽  
Collision Dynamics ◽  
Zakharov Equation ◽  
Fully Nonlinear

We numerically investigate pairwise collisions of solitary wave structures on the surface of deep water—breathers. These breathers are spatially localised coherent groups of surface gravity waves which propagate so that their envelopes are stable and demonstrate weak oscillations. We perform numerical simulations of breather mutual collisions by using fully nonlinear equations for the potential flow of ideal incompressible fluid with a free surface written in conformal variables. The breather collisions are inelastic. However, the breathers can still propagate as stable localised wave groups after the interaction. To generate initial conditions in the form of separate breathers we use the reduced model—the Zakharov equation. We present an explicit expression for the four-wave interaction coefficient and third order accuracy formulas to recover physical variables in the Zakharov model. The suggested procedure allows the generation of breathers of controlled phase which propagate stably in the fully nonlinear model, demonstrating only minor radiation of incoherent waves. We perform a detailed study of breather collision dynamics depending on their relative phase. In 2018 Kachulin and Gelash predicted new effects of breather interactions using the Dyachenko–Zakharov equation. Here we show that all these effects can be observed in the fully nonlinear model. Namely, we report that the relative phase controls the process of energy exchange between breathers, level of energy loses, and space positions of breathers after the collision.

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