GRAVITY CURRENT ANALYSIS OF THE BOSTWICK CONSISTOMETER FOR POWER LAW FOODS

Abstract

ABSTRACT Flow observed in the Bostwick consistometer was evaluated as a gravity current; the balance of forces yields the Bostwick measurement as a function of the geometry of the apparatus and fluid properties. Experimental measurements for Newtonian and power law fluids are compared to theoretical predictions. Although the theory can be used to evaluate values for power law parameters, the best results are obtained by predicting the ratio of apparent viscosity to density to the –0.2 power. The agreement between theory and experiment for homogeneous fluids is within 2%. Values of Bostwick measurement versus (η/ρ) −0.2 for tomato suspensions fall along the same curve as the homogeneous fluids.