INSTABILITY OF HAGEN-POISEUILLE FLOW FOR NON-AXISYMMETRIC MODE

摘要

An investigation is described for instability problem of flow through a pipe of circularcross-section.As a disturbance motion,we consider a general non-axisymmetric mode.Anassociated amplitude or modulation equation has been derived for this disturbance motion.This equation belongs to a diffusion type.The coefficient of it can be negative whileReynolds number increases,because of the complex interaction between moleculardiffusion and convection.The negative diffusivity,when it occurs,causes a concentrationand focussing of energy within decaying slugs,acting as a role of reversing natural