Affordable Thermomechanical Fatigue Testing under Turbine Airfoil Conditions in the Hyperbaric Advanced Development Environmental Simulator (HADES)

Emerging missions such as deep strike as supported through the VAATE program are being designed to operate at high overall pressure ratios, high turbine temperatures, and for extended periods of time.  A low-cost test facility that can reproduce those conditions is required to test the combustor and turbine materials and thermal/environmental barrier coatings that will be needed to satisfy operating parameters.  The test rig developed and demonstrated in this effort, will be capable of simultaneously thermally and mechanically loading the test articles to simulate actual engine conditions with heat flux values of 1.5 million BTU/hr/ft2 without film cooling.  The expectation is that the HADES rig TMF results will be different from conventional TMF tests because of the differences in strain gradients produced by both test methods. This test system will be an affordable alternative to engine testing or other materials testing approaches.  The degradation processes which could be studied with this rig include erosion, coating spallation, thermal mechanical fatigue, crack initiation, small cooling features, low cycle fatigue, hold-time effects, or the interaction of failure mechanisms on coatings and base alloys. BENEFIT: With the extremely high cost of developing a new engine concept, especially when operating conditions will exceed all current experience, low cost test rigs are the prudent way to screen and characterize materials and design concepts (i.e. advanced cooling schemes) prior to committing to actual engine hardware and full engine testing.  This service will benefit not only original equipment manufacturers of gas turbine engines, but also DoD and NASA agencies, thermal and environmental barrier coating manufacturers, space and rocket engine manufacturers and developers, manufacturers of advanced and engineered materials, and those developing innovative designs with known materials.