AeroMancer Technologies proposes to develop an 3D Airspeed Backscatter Correlation (3D-ABC) lidar velocimeter for in-flight boundary layer flow visualization and airspeed measurement in spatially and temporally resolved 3D flow fields using a rugged, eye-safe, daytime-capable, reliable Infrared (IR) optical device. AeroMancer’s technique for measuring 3-component spatially and temporally resolved airspeeds is based on the time-lag correlation of aerosol density fluctuations from a 3D map of lidar elastic backscatter signals. Other methods for standoff quantitative flow visualization of complex flow fields have limitations in outdoor testing. The strength of this approach and its advantage over other optical remote sensing techniques is the use of a single-ended system to simultaneously obtain 3D flow fields over a relatively large measurement volume (15m x 27° x 20°), with minimal setup time and to concurrently perform 3D hard-target mapping using an eye-safe optical system, thereby reducing size, complexity and alignment requirements.
In a recent NASA SBIR Phase II project, AeroMancer developed a novel prototype scanning lidar for high-resolution 3D global airspeed mapping in wind tunnels, which captures 3D maps of seeding particle density in the airflow using elastic backscatter from an eye-safe, 1550 nm wavelength IR lidar beam that is rapidly scanned using a new interleaved scanning method. A 3D cross-correlation algorithm is used to extract 3D airflow profiles from pairs of 3D images.
In this project, AeroMancer proposes to build on this existing design by identifying the measurement requirements for in-flight aerodynamic testing; system improvements to enable daytime operation; requirements for aircraft integration including size, weight power and cooling and eye-safety; and design changes to meet the needs of outdoor testing. Using recommendations from this analysis, AeroMancer will develop a conceptual design of the proposed instrument system.
A remote 3D velocimetry system for in-flight quantitative flow visualization can become an integral part of NASA flight test capabilities. The ability to obtain non-intrusive 3D concurrent airflow maps over a relatively large volume can be used to study key NASA challenges in aerodynamics, aeroacoustics and flight dynamics. In addition to flow visualization and airspeed sensing, the proposed instrument could also have potential NASA applications in blade tracking and aerosol transport.
Velocimetry has broad applicability to research, development, test and evaluation in a variety of industries from manned and unmanned air, land and sea vehicles for defense, wind tunnels for the automobile and racing industries, civilian aerospace, etc. Other applications include analyzing the effect of wakes on personnel and equipment at airports, offshore installations/building helipads, etc.