Centerline decay:
U_c(x) = U_j·(x_0/x)^(1/2)·(B·D/x)^(1/2)
Self-similar profile:
U(η) = U_c·exp(−η²/2), η=y/b(x)
Spreading: b(x) = K·x
Entrainment: dQ/dx = α·Q/x
Momentum: J = ∫ρU² dy = const (Tollmien)