Viscous flow The Navier-Stokes Equations Nonlinear, second order, partial differential equations au auau au a-u auau +l+y-+ +pgx+u at a a-y ay ay +ng1+1 at a ay az ax ay az a21a21 +g:+p O au ay a 0 ox ay a Couette flow. Poiseuille flow Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 3 Viscous Flow • The Navier-Stokes Equations Nonlinear, second order, partial differential equations. • Couette Flow, Poiseuille Flow.           +   +   + +   = −           +   +   +             +   +   + +   = −           +   +   +             +   +   + +   = −           +   +   +   2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 z w y w x w g z p z w w y w v x w u t w z v y v x v g y p z v w y v v x v u t v z u y u x u g x p z u w y u v x u u t u z y x          = 0   +   +   z w y v x u