Statement of work. Task: 8-foot high temperature tunnel mixer liner and mach 5 high dynamic pressure thermal analysis. 1.0 introduction/background: planned future testing in the NASA langley 8 HTT…

Statement of work. Task: 8-foot high temperature tunnel mixer liner and mach 5 high dynamic pressure thermal analysis. 1.0 introduction/background: planned future testing in the NASA langley 8 HTT requires operation of the existing facility mixer and mach 5 high dynamic pressure (M5HIQ) nozzle at temperature levels exceeding the design value for that hardware. The 8 HTT mixer is the low velocity region immediately upstream of the M5HIQ nozzle. Inside the facility mixer, dilution air and hot flow from the facility combustor are mixed together to form the entrance flow to the M5HIQ nozzle. For a nominal mach 5 test, the mixed flow temperature is approximately 2150 rankine. The facility has conducted numerous tests at this nominal mach 5 condition and is capable of delivering steady operational conditions for period of 100 seconds without exceeding high temperature interlocks installed at key locations on the mixer liner and M5HIQ nozzle. Future customers have identified test requirements at conditions simulating flight at mach 5.5. This simulation requires that both the mixer liner and the existing mach 5 nozzle be operated at temperatures that exceed the design value. IT is known that exceeding the design temperature is acceptable as long as the run time is shortened so that red-line temperature limits are not violated during a test run. However, the allowable run duration is not known. The allowable run time duration at temperatures exceeding the nominal design value must be known so that future facility users can determine how many runs are required for them to complete their required test matrix. 2.0 scope & objective(s): 2.1 the scope of this task order is to conduct an analytical study to determine the allowable run time (seconds) for the mixer and the M5HIQ nozzle at stagnation temperature levels exceeding the nominal design level at nozzle inlet stagnation pressure levels provided as government furnished information (GFI) under this task order. 2.2 the objectives of this task order are to: 2.2.1 analytically determine the allowable run time for the existing 8 HTT mixer and M5HIQ nozzle at two conditions exceeding the nominal design temperature level. 2.2.2 identify the limiting factor on run time for each mach condition and investigate design modifications that would extend the run time limits. 3.0 description of the work/tasks to be performed: the contractor shall perform the following tasks: 3.1 mixer liner and M5HIQ transient thermal analysis: (deliverable item 4.3) 3.1.1 the contractor shall construct a single transient thermal model of the mixer and M5HIQ nozzle. The thermal model shall be constructed from mixer liner and M5HIQ hardware geometry and material information furnished by the government (GFI 5.1). 3.1.2 the contractor shall utilize the transient thermal model developed in SOW task 3.1.1 to conduct transient thermal analyses at two different conditions specified by the NASA tech POC. The two different analysis conditions provided by the government (GFI 5.2) will consist of the mixer stagnation pressure, the mixer stagnation temperature, and the total flow rate through the mixer and M5HIQ nozzle. The conditions provided as GFI 5.2 will be representative of flight simulation at mach 5.3 and mach 5.5. The transient thermal analysis shall be utilized by the contractor to predict the time required for the mixer and / or M5HIQ nozzle to exceed red-line temperature limits at the two flight simulation conditions. 3.1.3 the contractor shall identify the axial locations in the mixer / nozzle assembly where the temperature exceeds material limits. Approaches to mitigate the limiting condition shall be identified and presented as part of the final presentation.