Blade-Tip-Clearance Forces in Turbines

Abstract

Study reviews field and proposes experiments. Report summarizes present knowledge and discusses plans for experiments on blade-tipclearance excitation forces in turbines. Of particular interest Alford forces, named after pioneering worker in this field. These are cross forces due to uneven clearances, which in turn caused by and also cause rotor vibrations. Because blade-tip clearances affect turbine efficiency and excitation forces affect rotor stability, report proves useful to researchers and designers of advanced turbomachinery.