Intermittent patterns in mixed convection

Abstract

We have performed a Laser Doppler anemometry study of the mixed convective flow of water in a horizontal, rectangular duct of 4.15 mm height, 115 mm length and 15.05 mm width. This study has revealed a particular flow regime that lies approximately between 1920<Ra<2080 and 0.45<Re<0.75, in which only irregular and intermittent flow structures are observed. Small excursions in Re or Ra beyond these bounds result in the stabilization of either longitudinal or transverse rolls.