Research on Storage Heaters for High Temperature Wind Tunnels

摘要

The results from the materials development program for the ceramics of the storage heater system for high temperature wind tunnels are presented. A number of ceramic oxides were evaluated including magnesia, zirconia, and alumina. Magnesia was dropped as a candidate early in the program because of the high vaporization rate experienced in a flowing combustion gas atmosphere. Zirconia was evaluated in its stabilized form using calcia, magnesia, and yttria as the stabilizing oxides. Yttria-stabilized zirconia evolved as the candidate material for the upper portion of the heater matrix (2800F to 4200F) and alumina for the lower portion (1000F to 2800F). The development program evaluated materials in both subscale and pilot scale tests. The performance of the individual materials during the various subscale tests is discussed. The design basis for a pilot facility is presented along with the material performances following the 85 run, pilot heater test program. Specifications for materials used in the pilot facility are presented along with a cored block specification prepared based on the development program. (Author)