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Euler equation added; I might try to expand the article a bit: Navier-Stokes equation, Bernoulli equations and their consequences, and so on. Nothing too fancy... I will also add references.
'''Fluid dynamics''' is the study of how [[fluid]]s move. Fluids include [[water]] and [[Gas|gases]] (such as [[air]]).<ref>http://virtualskies.arc.nasa.gov/glossary/F.html</ref>
'''Fluid dynamics''' is the study of how [[fluid]]s move. Fluids include [[water]] and [[Gas|gases]] (such as [[air]]).<ref>http://virtualskies.arc.nasa.gov/glossary/F.html</ref> Fluid dynamics is also known as continuum mechanics, as fluids cannot be treated as point objects; [[Newton]]'s second law thus becomes Euler equation
<math>\frac{D\mathbf{u}}{Dt} = - \frac{1}{\rho}\nabla p + \mathbf{g},</math>
where <math>\rho</math> is the [[density]] of the fluid, '''u''' its velocity and '''g''' the gravitational acceleration. The [[operator]] <math>D/Dt = \partial/\partial t + (\mathbf{u}\cdot\nabla)</math> is the convective derivative, the rate of change of a certain quantity ''A(t)'' of the fluid as it is carried by the fluid (hence the presence of '''u'''). Euler equation is then a differential operation explicitly relating the effects of the gravity and the gradient of pressure on the velocity of the fluid.
As long as the [[speed of sound]] is much larger than '''u''', the density <math>\rho</math> of the fluid can be considered as constant (incompressible).
==References==
==References==