Ceramic Rotating Blades: Some Critical Design Parameters for Gas Turbine Applications

Abstract

A three-dimensional analysis of a ceramic rotating blade is presented. The analysis reveals that under a centrifugal force load the maximum stress occurs in the root of the blade. The root, a critical area for this blade, is then analyzed in detail in an effort to reduce this stress. This requires a study which considers the effect of friction, contact area, and root geometry on root stresses. This paper is the first step in a feasibility study to ascertain if ceramics are applicable to rotating blades for heavy duty gas turbines. The next step will be to determine the transient thermal and vibratory stresses in the ceramic blade during a turbine operating cycle.