A New Approach for a Low-Cooled Ceramic Nozzle Vane

Abstract

At the Institute for Thermal Turbomachinery, University of Karlsruhe (ITS) a new methodology for designing thermally loaded ceramic components based on numerical analyses of the thermal and structural behaviour is developed. Major issues are an effective optimization of the geometry and an assessment of the load. To reduce thermally induced stresses in shell structures exposed to hot gas flow a precise description of the major influencing parameters is required. Based on these relations a thermal optimization of the component is possible. Moreover, the compensation of thermal strains and the adjustment of local stiffnesses for reducing the tensile stresses and the failure probability has to be considered. In designing a first stage vane of a stationary gas turbine the proposed guidelines are verified. The advantages of a systematic approach are demonstrated. The multi-purpose numerical procedures using the guidelines allow an adjustment of the shape to thermally and mechanically induced loads and offer new possibilities to meet the specific demands of ceramic materials.