Chaotic Oscillations of a Square Prism in Fluid Flow

✍ Scribed by S. Narayanan; K. Jayaraman

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 450 KB
• Volume: 166
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1993.1285

✦ Synopsis

Chaotic motion of a harmonically excited square prism modelled as a Duffing oscillator and kept in fluid flow is considered. The fluid dynamic forces contribute additional nonlinear terms to the inherent non-linearity of the system. The harmonically excited oscillator without the fluid fow exhibits three types of steady state periodic motions, dual period 1 motions and period 3 motion without dual. The flow changes the nature of motion of the oscillator. With the flow velocity as bifurcation parameter, the system exhibits period 1 motion without dual, bifurcating into dual period 1 motions which period double into dual period (2,4,8) motions, etc., leading to chaos as the flow velocity is increased. Lyapunov exponents for different flow velocities are computed which show the bifurcation points. The harmonic balance method is used to obtain approximate solutions for the periodic motions and to predict the period doubling bifurcations by a stability analysis.