ABSTRACT
In the {x,y} plane, the lines of constant stream function ψ are called streamlines. The velocity vector is tangential to the streamlines everywhere.
1.2.2 Velocity potential For irrotational flows, the relationship between the velocity vector and velocity potential is:
Vx = −∂φ ∂x
Cartesian coordinates (3.2b1)
Vy = −∂φ ∂y
(3.2b2)
Vr = −∂φ ∂r
Polar coordinates (3.2c1)
Vθ = −1r × ∂φ
∂θ (3.2c2)
In the {x,y} plane, the lines given by φ= constant are called equipotential lines.
