TRANSITION FROM LAMINAR TO TURBULENT FLOW IN A LASER-INDUCED CONVECTION COLUMN

Abstract

Transition from laminar to turbulent flow in a laser‐induced vertical convection column has been observed using a CO₂–N₂ laser in CO₂ gas. The onset of turbulence is measured with a fine‐wire resistance thermometer and laser power meter. The transition boundary in terms of cell pressure p and incident laser power P₀ at a fixed beam diameter and cell geometry is found to be approximately given by p²P₀ = constant, which can be shown to imply a constant‐transition Reynolds number for the induced flow under certain restrictive conditions.