High Heat Flux Activity Cooled Honeycomb Sandwich Structural Panel for a Hypersonic Aircraft.

This report presents the results of a program to design and fabricate an unshielded actively cooled structural panel for a hypersonic aircraft. The design is an all-aluminum honeycomb sandwich with embedded cooling passages ordered to the inside of the outer moldline skin; the coolant is a 60/40 mixture of methanol/water. The panel was mass optimized to sustain 20000 cycles (5000 x scatter factor of 4) of + or - 210 kN/m (+/- 1200 lbf/in.) inplane loading combined with a 6.9 kPa (+/- 1.0 psi) uniform pressure while subjected to a 136 k W/m (12 BTU/ft(2) uniform beat flux. Six fatigue specimens, of critical panel areas, were fabricated by McDonnell Aircraft Company and tested (at room temperature) by NASA. A representative test panel was not fabricated because of problems with the plotting/soldering process. The overall finding is that an actively cooled structure appears feasible for application on a hypersonic aircraft, but the fabrication process is complex and some material and manufacturing technology developments are required. Results from the program are summarized in the body of the report and supporting details are presented in several appendices. (AN)