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Actually this is confirmed by state-of-the-art experiments (see [3]) in which the discharge, the outflow velocity and the cross-section of the vena contracta were measured. Here it was also shown that the outflow velocity is predicted extremely well by Torricelli's law and that no velocity correction (like a "coefficient of velocity") is needed.
This velocity is the asymptotic limiting value of the acceleration process, because the effective forces on the body balance each other more and more closely as the terminal velocity is approached. In this example, a speed of 50 % of terminal velocity is reached after only about 3 seconds, while it takes 8 seconds to reach 90 %, 15 seconds to ...
The condition can be expressed in a number of ways. One is that there cannot be an infinite change in velocity at the trailing edge. Although an inviscid fluid can have abrupt changes in velocity, in reality viscosity smooths out sharp velocity changes. If the trailing edge has a non-zero angle, the flow velocity there must be zero.
V A is the design maneuvering speed and is a calibrated airspeed.Maneuvering speed cannot be slower than and need not be greater than V c. [4]If is chosen by the manufacturer to be exactly the aircraft will stall in a nose-up pitching maneuver before the structure is subjected to its limiting aerodynamic load.
Siacci found that within a low-velocity restricted zone, projectiles of similar shape, and velocity in the same air density behave similarly; or . Siacci used the variable for ballistic coefficient. Meaning, air density is the generally the same for flat-fire trajectories, thus sectional density is equal to the ballistic coefficient and air ...
It takes energy to push a fluid through a pipe, and Antoine de Chézy discovered that the hydraulic head loss was proportional to the velocity squared. [5] Consequently, the Chézy formula relates hydraulic slope S (head loss per unit length) to the fluid velocity V and hydraulic radius R: = =
The mathematical by-product of this calculation is the mass–energy equivalence formula, that mass and energy are essentially the same thing: [14]: 51 [15]: 121 = = At a low speed (v ≪ c), the relativistic kinetic energy is approximated well by the classical kinetic energy.
where Re is the Reynolds number, ρ is the fluid density, and v is the mean flow velocity, which is half the maximal flow velocity in the case of laminar flow. It proves more useful to define the Reynolds number in terms of the mean flow velocity because this quantity remains well defined even in the case of turbulent flow, whereas the maximal ...