[01] Arezu Jahanshir, Department of Eng. Physic, Buein Zahra Technical University, Qazvin, Iran.

This article describes the aeroelastic flutter phenomenon at ultra-speed limits. Flutter initiates when the air-flow speed is over a certain flutter onset speed and the air-flow direction is nearly perpendicular to the moving body. It is the oscillatory instability in a potential air-flow, in which neither separation nor strong shocks are involved, which is essentially the continued and increasing oscillation of a moving body that is sustained only by the movement of a fluid over it, at a constant speed. It is important to understand the cause and effects of ultra-high speed to get a more accurate sense of how to prevent flutter from occurring during traveling at high speeds. At fairly constant air-flow speed the moving body was pushed in to aeroelastic phenomenon based on its dynamic and aerodynamic characteristics. Mechanical engineers are familiar with forced and resonance characteristic of moving systems at high speeds, but usually not with relativistic effects of motion at ultra-high speeds. In the real world, there exists the content of the principle of relativity, which is one of the basic postulates of the special theory of relativity. One of the most surprising features of special relativity is that a number of statements and results which we usually think to be absolute turn out to be observer-dependent. In particular, statements about space and time, distances and duration turn out to be relative. Similarly, temporal duration depends on the observer. This relativistic effect is called time dilation. Summarized briefly: Moving clocks are slower than stationary ones. A bit more precisely: An observer on station A measures time using his on-board clock. Station B, passing A at high speed, has an exact copy of A's clock on board. Yet, from the point of view of A, the clock in station B runs more slowly than his own. In this paper, we try to study length time of starting moment of flutter at ultra-relativistic limits with relativistic theory which determine and measure various quantities related to the velocities of observers when time is dilates.

Ultra-High Speed, Supersonic Vehicle, Relativistic Speed, Lorentz Invariant

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