Evaluation of Embedded Miniature Pressure Scanners for Unsteady Measurements in a Low-Speed Wind Tunnel Testing Application
In many aerodynamic measurement applications, the ability to make time-accurate measurements with pressure scanners provides practical advantages over making the same measurements directly using flush-mounted transducers. However, the pneumatic distortion due to the tubing between the sensing module and surface port limits the usefulness of such measurements to averaged, steady data only. This issue has restricted the application of pressure scanners for unsteady pressure measurements in the wind tunnel and flight-testing applications. The Wiener-filtered inverse system response model has been proven effective in reconstructing complex unsteady pressure signals acquired remotely using pressure scanners. The unparalleled long-term thermal stability, flexibility and robustness that pressure scanners provide in wind-tunnel and flight-testing applications, combined with an ability to reconstruct the unsteady components of the measured pressure signals, could enable their use in modern applications involving dynamic flow fields and highly separated flows. This work evaluated the feasibility of using pressure scanning systems for time-resolved pressure measurements in the NASA Langley 14- by 22-Foot Subsonic Wind Tunnel. Results demonstrated good agreement between the reference transducers and reconstructed pressure scanner measurements up to frequencies of approximately 500 Hz.
Evaluating the Utility of Pressure Scanners for Unsteady Pressure Measurements in Wind Tunnel Characterization of the Space Launch System
In many aerodynamic measurement applications, the ability to make time-accurate mea- surements with pressure scanners provides practical advantages over making the same mea- surements directly using flush-mounted transducers. However, the pneumatic distortion due to the tubing between the sensing module and surface port limits the usefulness of such mea- surements to averaged, steady data only. This issue has restricted the application of pressure scanners for unsteady pressure measurements in the wind tunnel and flight-testing applications. The Wiener-filtered inverse system response model has been proven effective in reconstructing complex unsteady pressure signals acquired remotely using pressure scanners. The unparalleled long-term thermal stability, flexibility and robustness that pressure scanners provide in wind-tunnel and flight-testing applications, combined with an ability to reconstruct the unsteady components of the measured pressure signals, could enable their use in modern ap- plications involving dynamic flow fields and highly separated flows. This work evaluated the feasibility of using pressure scanning systems for time-resolved pressure measurements in the NASA Langley 14- by 22-Foot Subsonic Wind Tunnel. Results demonstrated good agreement between the reference transducers and reconstructed pressure scanner measurements up to frequencies of approximately 500 Hz.
Characterization of Unsteady Pressures on a Blunt Trailing Edge Using a Direct-Mount Pressure Scanner
In recent years, the demand for using pressure scanning modules for unsteady aerody-
namic measurements has increased. Development of small, compact direct-mount pressure scanners can decrease the pneumatic tubing length required to connect the measurement ports to the scanner manifold resulting in improved dynamic range for unsteady pressure measurements. In this work, the performance of a direct-mount pressure scanner for time-resolved pressure measurements is demonstrated in a well-known flow; the pressure fluctuations near the base of a symmetric flat plate. The additive manufactured model is instrumented with a direct-mount pressure scanner and a flush-mounted high-speed pressure transducer. Additional ports routed to a conventional pressure scanner outside the wind tunnel are also available. The configuration of the ports on the model allows for comparison of the unsteady pressure measurements acquired via short and long tubing systems with that measured by the high-speed transducer. Prior to testing, the dynamic response of each pressure port is dynamically characterized via an in-situ calibration technique. Pressure data are then acquired for fixed angle-of-attack as well as for different dynamic pitching conditions. The dynamic range of the three different pressure measurement configurations are considered for both static and dynamic pitching conditions.