Surface velocity measurements are a key component of understanding the flow over an aerodynamic surface and can be challenging in a complex (i.e. bi-directional transient) flow. The proposed technology is a novel surface velocity sensor that is insensitive to inertial loads and thermal effects and can provide magnitude and direction of flow over a surface. The sensing technique uses a plasma field generated between cathode and anode leads that is deflected due to the air flow. A novel configuration of leads enables velocity measurement using a differential response of electrical impedance across the leads. Results from high fidelity simulations validate this novel sensing approach. During the proposed effort, a prototype sensor will be developed and fabricated for proof-of-concept hardware demonstration. Data from benchtop testing with the sensor will be compared with conventional measurements to demonstrate sensitivity to surface flow velocity. The Phase I prototype sensor will be integrated into a blade section and tested in an open-jet wind tunnel. The results of the proposed effort will set the stage for the Phase II program to further refine the sensor to improve sensitivity, develop electronics hardware, and testing in a relevant rotating environment.
The proposed sensor technology would be used in NASA testing facilities including wind tunnels and experimental aircraft. Additional applications include challenging testing environments including rotor blade and propeller blade surface flow measurement.
The sensor would be used in military and commercial wind tunnel testing facilities used to evaluate performance of systems including fixed wing vehicles, rotary wing vehicles, ground vehicles, and wind turbines. The sensor system would be used in instrumenting rotor blades for Vertical Take-off and Landing configurations and in difficult to instrument areas on advanced fixed-wing configurations.