Continuity equation

The most general form for the continuity equation is expressed as

∂ρ
∂t
 + ∇·(ρv ) = 0,
(1)
where ρ is the density and v is the velocity field.
For steady-state and ρ = const, the equation above is simplified to (2-D)

∇·v = 0,
or
∂u
∂x
 + ∂v
∂y
 = 0.


File translated from TEX by TTH, version 4.03.
On 05 Mar 2023, 21:18.