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Bernoulli's principle is a key concept in fluid dynamics that relates pressure, speed and height. Bernoulli's principle states that an increase in the speed of a parcel of fluid occurs simultaneously with a decrease in either the pressure or the height above a datum. [1]:
The relationship between pressure and velocity in fluids is described quantitatively by Bernoulli’s equation, named after its discoverer, the Swiss scientist Daniel Bernoulli (1700–1782). Bernoulli’s equation states that for an incompressible, frictionless fluid, the following sum is constant:
20 Οκτ 2020 · What Bernoulli's equation actually says is that the velocity will increase in the direction of decreasing pressure: P2 −P1 = −12ρ(v22 −v21) P 2 − P 1 = − 1 2 ρ (v 2 2 − v 1 2). This makes sense: if the pressure is higher on the left than on the right, then the fluid will speed up to the right.
Bernoulli’s principle reinforces the fact that pressure drops as speed increases in a moving fluid: If v 2 is greater than v 1 in the equation, then p 2 must be less than p 1 for the equality to hold.
This is what Bernoulli's equation does, relating the pressure, velocity, and height of a fluid at one point to the same parameters at a second point. The equation is very useful, and can be used to explain such things as how airplanes fly, and how baseballs curve.
ρ (Greek letter rho) is the fluid mass density (e.g. in kg/m 3), and. u is the flow speed in m/s. It can be thought of as the fluid's kinetic energy per unit volume. For incompressible flow, the dynamic pressure of a fluid is the difference between its total pressure and static pressure.
Velocity vectors are often used to illustrate fluid motion in applications like meteorology. For example, wind—the fluid motion of air in the atmosphere—can be represented by vectors indicating the speed and direction of the wind at any given point on a map.
