Additively Manufactured Internally Cooled Window Frame

Mounting of infrared (IR) windows on hypersonic vehicles is a critical design issue because of the stresses caused by high temperatures combined with the coefficient of thermal expansion (CTE) mismatch between the window and frame materials. Many applications use elastomeric seals to limit window distortion and stress by allowing for joint flexibility. However, windows and frames operating in this environment can reach temperatures exceeding 900°C that would cause failure of these seals. Mainstream proposes to reduce window stress from the frame by cooling both the frame and the window. Optimized cooling of the frame and vehicle forebody requires small, conformal cooling passage geometries that are difficult to fabricate using standard manufacturing methods. Therefore, metal additive manufacturing will be used to generate cooling passages in the frame. The effort will ultimately produce a cooled window and frame for testing at a hypersonic wind tunnel. Approved for Public Release | 20-MDA-10601 (19 Oct 20)