High Temperature Mach number or Static Pressure Probes for Vitiated Flows

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics; Integrated Sensing and Cyber; Advanced Materials OBJECTIVE: Develop and demonstrate a local Mach number or Static Pressure probe technology suitable for hypersonic and high enthalpy flows. DESCRIPTION: The Aerodynamic and Propulsion Test Unit (APTU) at the Arnold Engineering Development Complex (AEDC) is a high-speed hypersonic (HS/H) test facility capable of producing flight representative conditions (true temperature and pressure) via a combustion air heater (CAH). Understanding of any HS/H system under test requires a thorough understanding of the as-delivered free stream test conditions. The test conditions are typically characterized during dedicated test runs using intrusive diagnostics such as flow-field rakes with multiple discrete probes. Currently, the probes are limited to the assessment of total pressure and temperature with no direct measurement of local static pressure or Mach number. As such several assumptions and iterative techniques are required to assess the flow-field characteristics. With only wall statics along the nozzle inner mold line, analysis is limited to assuming a uniform static pressure across the flow field. Any divergence in the static pressure from this assumption is superimposed on the total pressure and Mach number profiles. A direct measurement of either static pressure or Mach number will negate the need for the assumptions and reduce the overall uncertainty of test results. PHASE I: Consult with AEDC personnel to understand APTU operations and gain familiarity with current intrusive rake and probe designs. Survey industry to assess potential solutions to the problem, including later commercialization opportunities. Develop the concept and design of the probe technology for the APTU flow-field conditions. Evaluate the achievable measurement uncertainty and illustrate plans for state-of-the-art improvements. PHASE II: Develop and demonstrate a prototype probe-rake devices in the APTU flow-field conditions early into the Phase II to allow design iterations design as needed to demonstrate robustness and sufficient accuracy. PHASE III DUAL USE APPLICATIONS: Reduce device complexity and size for use within the facility rake systems. This technology will result in a product easily commercialized to other highspeed and high temperature wind tunnels. REFERENCES: Porro, R. A. (2001). Pressure Probe Designs for Dynamic Pressure Measurements in a Supersonic Flow Field. NASA Glenn Research Center. Cleveland, OH. Retrieved 12 2, 2022, from https://ntrs.nasa.gov/api/citations/20010093214/downloads/20010093214.pdf; Pinckney, S. Z. (1975). A Short Static-Pressure Probe Design for Supersonic Flow. NASA Langley Research Center. Hampton, VA. Retrieved 12 2, 2022, from https://ntrs.nasa.gov/api/citations/19750019233/downloads/19750019233.pdf; Pinckney, S. Z. (1975). US Patent 3914997; Capone, F. J. (1961). Wind-Tunnel Tests of Seven Static-Pressure Probes at Transonic Speeds. NASA Langley Research Center. Hampton, VA. Retrieved 12 2, 2022, from https://ntrs.nasa.gov/api/citations/19980227993/downloads/19980227993.pdf; KEYWORDS: High Temperature; High Pressure; Scramjet; Ground Testing; APTU