Eigenvalue bounds for Orr-Sommerfeld equation. ``No backward wave'' theorem
The linear stability of plane Poiseuille flow is considered. Lower and upper bounds for the phase velocity of an arbitrary unstable or marginally stable wave are established, that rule out the possibility of backward waves. It is shown that the overstability (not the principle of exchanges of stability) is valid for the plane Poiseuille flow.
scientific article; zbMATH DE number 955211