@wikipedia
The fluid flow with zero material derivative of its density:
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\frac{D \rho}{ Dt} = \frac{\partial \rho}{\partial t} + \rho \cdot \nabla {\bf u} = 0 |
This also implies that material balance equationwhich is equivalent to (with account of Continuity equation):
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anchor | 3divergence |
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alignment | left |
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\frac{\partial \rho}{\partial t} + \nabla (\rho \, {\bf u}) = 0 |
simplifies to:
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\nabla {\bf u} = 0 |
and means that velocity of Incompressible flow is solenoidal.
The term Incompressible flow is a misnomer as it does not necessarily mean It does not necessarily means that the fluid itself is incompressible.
In many practical applications condition
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is met for compressible fluids (at least when fluid compressibility is relatively small) and the fluid flow satisfies LaTeX Math Block Reference |
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and is called incompressible flow.
See also
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Physics / Mechanics / Continuum mechanics / Fluid Mechanics / Fluid Dynamics / Fluid flow
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