AbstractsEngineering

An analysis of the velocity and the shape of large gas bubbles rising through tubes filled with viscous liquids is presented. Four tubes, with diameters ranging from 0. 446 inches to 3. 97 inches, and three liquids, with viscosities ranging from one to 200 centipoise, were used in the study. Data are correlated using the three dimensionless parameters characteristic of the system: the Reynolds number, the Froude number, and the Weber number. At high Reynolds numbers the Froude number was constant at a value of 0. 126, agreeing well with the theoretically predicted value of 0. 122 for a perfect fluid. At Reynolds numbers below 5000, the Froude number decreased sharply, with the Reynolds number of the flow and the surface tension of the liquid both affecting this decrease. The shape of the rising bubble was found to be independent of the tube diameter and of the physical properties of the liquid. The bubbles were all found to be spherical-capped.