Christian J. Rahnke

Application of performance and reliability concepts to the design of ceramic regenerators

Four regenerator matrix samples, fabricated by different manufacturing methods and consisting of different ceramic materials and cell geometries, were studied to determine their reliability and performance potential in a typical industrial gas turbine engine. Hypothetical regenerators were designed from these matrix samples to give identical engine performance, and the thermal stress was determined for each. In some instances, it was necessary to stress relieve and preload the rims in order to reduce the thermal stresses so that acceptable reliability could be obtained. The four hypothetical regenerators were then compared on the basis of size, cost, leakage, etc., so that the advantages of each configuration could be observed. The performance and reliability analysis was based on Ford Motor Companys shuttle rig performance tests and over 200,000 core-hours of engine test on ceramic regenerators. The engine test program is described in detail.

Development of the AGT101 regenerator seals

The design and development of the regenerator seals used in the AGT101 gas turbine engine are described in this paper. The all ceramic AGT101 gas turbine engine was designed for 100 hp at 5:1 pressure ratio with 2500F(1371C) turbine inlet temperature. Six distinct phases of seal design were investigated experimentally and analytically to develop the final design. Static and dynamic test rig results obtained during the seal development program are presented. In addition, analytical techniques are described. The program objectives of reduced seal leakage, without additional diaphragm cooling, to 3.6 percent of total engine airflow and higher seal operating temperature resulting from the 2000F (1093C) inlet exhaust gas temperature were met.