Experiment Measurement of Alford's Force in Axial-Flow Turbomachinery,
TEXAS A AND M UNIV COLLEGE STATION DEPT OF MECHANICAL ENGINEERING
Pagination or Media Count:
In 1965, J. S. Alford published a theory and mathematical model 1 which predicts that circumferential variation of blade-tip clearances in axial-flow turbomachinery will produce cross-coupled normal to the eccentricity aerodynamic forces on the rotor. Ever since then, the theory has been used without experimental verification by rotor dynamicists as one of the few mathematical models available to calculate the cross-coupled aerodynamic stiffness coefficients required for rotordynamic stability analysis. This paper presents the results of experimental measurements made on a small, high speed, axial flow test apparatus to verify the existence of Alfords force and to investigate the validity of his mathematical prediction model.