Shock response oscillator

Figure 14. Shock Response for Blast-Loaded Elastic Oscillator.

Two principal mechanisms that may be responsible for mass loss from red giants are considered shock wave-driven winds and radiatively (dust)-dr iven winds. Effect of the periodic shocks accompanying nonlinear oscillations of red giants is most prominent in the outer layers of the stellar atmosphere where shocks are able not only to expel gas but also increase gas density so that some molecular components become supersaturated. In 0-rich stars the most abundant condensible species are silicon monoxide and iron, whereas in C-rich stars these are carbon, silicon carbide and iron. 

Nonlinear phenomena, usually associated with high amplitudes of the acoustic field, can introduce many interesting effects into acoustic instability [76]. Here we shall discuss only three topics involving nonlinearity the response of the combustion zone to transverse velocity oscillations (conventionally termed velocity coupling), changes in the mean burning rate of the propellant in the presence of an acoustic field, and instabilities that involve the propagation of steep-fronted waves (identified in the introduction as shock instabilities). 

An important area of dynamics has to do with problems where bodies oscillate in response to external disturbances. The exciting disturbances may be due to imbalance of rotating machinery a sudden shock, as in an earthquake or a periodic series of forces, as in an internal combustion engine. Self-excited vibrations exist when a system, once disturbed, vibrates indefinitely. This occurs when the energy stored exceeds that which is released during a cycle of vibration. In such cases, the amplitude of vibration continues to increase imtil the increase in energy lost per cycle in... 

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