01
Continuity
Conservation of mass requires the flow into and out of a control volume to balance appropriately.
∂ρ/∂t + ∇·(ρv) = 0
02
Bernoulli Principle
P + 1/2ρv² + ρgh = constant
The Bernoulli relation applies under restrictive assumptions, including steady, incompressible, inviscid flow along a streamline.