Testing of regeneratively cooled light-weight panel

Two types of actively cooled light-weight panels for use in scramjet engines were fabricated. They were made of Hastelloy X, and the photo-etching method was applied for constructing many cooling passages in these panels. One type of panels had a honeycomb structure which was brazed at the back of the panel for reinforcement. A vitiated-airflow generator and a device for supplying coolant were applied to evaluate the cooling ability of the panels. The vitiated airflow had a total temperature of 2000 K 3000 K, a total pressure of 1.0 MPa 1.5 MPa, and a Mach number of 3.1 3.4. The coolant used in this series of tests was water. No damage was observed in these cooled panels after testing. We measured the heated-surface temperature of the panels using a radiation thermometer, and strain at the center of the rear surface of the panel was determined with strain gages. The radiation thermometer indicated a temperature of about 500 K 780 K on the heated-side surface depending on the heat flux. The strain measured during the test was mainly due to thermal stress. The honeycomb structure was able to reduce the apparent strain caused by thermal stress. This indicates an incrcase of rigidity in the panel. *Researcher, Ramjet Structure Section, Ramjet Propulsion ?Senior Researcher, Ramjet Propulsion Research Division. Research Division.