Directed Energy Wind Tunnel Test Methodology

ABSTRACT:MZA partnered with the University of Notre Dame proposes advancement of aero-optical isolation hardware, data processing, and optical modeling for upgrade of AEDCs 16T wind tunnel. We will conduct testing at AEDC during Year 1 with mechanical diagnostics and an upgraded optical sensor with small-aperture access to the test section from outside the 16T pressure vessel. We will also design and implement a remotely-operated optical diagnostic sensor bench with environmental enclosure for use inside the AEDC pressure vessel. The sensor bench will include a high-speed wavefront sensor and beam expander enabling full-aperture aero-optics measurements. The remote optical diagnostic sensor bench will be tested initially at Notre Dames White Field wind tunnel in Year 2, verifying system functionality and isolation of aero-optical disturbances from a surrogate laser turret. We will conduct Year 2 testing at AEDC with the remote optical diagnostic sensor bench inside the 16T pressure vessel, enabling a large aperture wavefront measurement of the tunnel boundary layer. The sensor bench and test experience at AEDC will enable development of a conceptual design for AEDCs aero-optics isolation test section. The conceptual design will be captured in a WaveTrain optical model for virtual testing of future laser DE systems at AEDC.BENEFIT:The tunnel measurement system proposed here will allow AEDC and other wind tunnel facilities to isolate contaminating optical disturbances induced by the test section from aero-optical effects which are characteristic of laser directed energy systems and their associated beam director turrets/apertures. This system will improve the quality of aero-optical test data measured in subscale and full-scale wind tunnel tests for assessing performance limitations and operational envelopes of laser systems prior to costly aircraft integration and flight testing. Such a system will also help to identify sources of disturbances in the tunnel and suggest strategies for minimizing or eliminating these contaminants. Once tunnel disturbances are abated, additional testing such as real-time laser beam control tests can also be conducted in tunnels at AEDC. After proven successful for AEDC, the proposed measurement system, data processing, and optical modeling can be extended to other wind tunnels at government, industry, and academic facilities. The system may also be incorporated into a transportable Optical Diagnostic Range Simulator hardware used for testing laser systems in laboratory or hangar. The same product can be used in operational laser tests using a wind tunnel test section, becoming an integral part of the directed energy system developmental cycle.