Study of the Oscillation of a Gas-Column Caused by Heat Conduction in a Tube : Limiting Condition for the Onset of Oscillation in a Tube with No Inner Flow

Abstract

Experimental study has been made on the limiting condition for the onset of oscillation in a straight tube holding a heater and a cooler in it. Under the experimental conditions of the tube length l set at 1410 mm to 3200 mm, the relative location of heater l_h/l, 1/12, 1/8, 3/16, 1/4, 5/16 and 3/8, and the distance between heater and coolerδ 5mm, 6mm and 7mm, the temperature difference between heat and cooler at the limiting condition of oscillation ΔT is found to be correlated by ((ΔT)/δ)ⁿl/δsin(l_h/lπ)cos(l_h/lπ)=C when n and C are constants depending on the shape and the orientation of heater and cooler. The above correlation is not in a sufficient form dimensionally, but it may be assumed that quantitative regularity obtained by this study gives an important guide to the future study of the thermal onset of oscillation of a gas-column.