Design issues in using integral textile ceramic composites in turbine engine combustors

Integrally formed ceramic matrix composite structures are being developed for a range of hot-structure applications involving active cooling. Integral textile structures offer several advantages: 1) Joints between ceramic and other materials in hot zones can be avoided. 2) Thin skins (<1 mm) can be formed that are strong and tough, enabling tolerance of higher heat fluxes and the use of materials, such as oxide-oxide composites, with attractive environmental stability but relatively low conductivity and high thermal expansion. 3) Compliant structures can be designed, which can limit the development of thermal mismatch stresses. 4) Fabrication costs can be lowered by reducing part counts and steps in processing. Preliminary analyses are presented that demonstrate how these benefits might be realized for an advanced annular combustor. The possibility of a very attractive design space is indicated, based on reasonable assumptions for heat transfer coefficients for the parameter regime relevant to the new designs.