Masking the Sun and Scoping the Problem

Masking the Sun and Scoping the Problem

Innovative hardware upgrades to Armstrong's Airborne Schlieren Imaging System (ASIS) are improving reliability and precision. The ASIS platform captures shockwave images by aligning a supersonic aircraft between a camera-equipped aircraft and the sun, and then watching as the shocks put an apparent ripple

on the sun's edge. The technique enables researchers to validate data from supersonic models and wind tunnel tests. Armstrong engineers recently designed and implemented adjustments to the ASIS Forward-Looking Infrared (FLIR) camera pod to improve its performance.

Work to date: Innovators developed highly precise solar masks that block all but the very edge of the sun. Since the apparent solar radius changes throughout the year due to Earth's changing proximity to the sun, the team created two masks that are 0.001 inches different in radius-one for a summer mean radius and another for a winter mean. A programmable tooling machine made manufacturing the masks straightforward; the harder challenge was inspecting them. The

team employed a laser projection device to create well-defined and accurately enlarged mask images, enabling small radial measurements. The group also used borescopes to view a 'blind' connector that did not fully mate during pod assembly, causing routine flight vibrations to induce intermittent system failures. A new connector scheme allows for a more robust and fully mated connection.

Looking ahead: The team will continue to test and mature the technology and to identify potential research partners.

_' Armstrong has the tools, ingenu-ity, and skills on hand to tackle difficult problems. The ASIS team made full use of these skills when developing and improving the system. We look forward to

obtaining elusive aircraft shock visuals with this equipment. _'

Paul Bean, PI

Engineering Successes

Armstrong's Research and Engineering Directorate is responsible for the overall engineering content of flight research projects. Our engineers provide technical expertise in aerodynamics; guidance, navigation, and control; propulsion; static and dynamic structures; flight hardware and software; flight and ground test instrumentation and data systems; and system engineering and integration. They apply their expertise across the spectrum of Armstrong's many activities and also support the development and continual evolution of engineering tools and test techniques. Here are highlights from a few recent and particularly notable engineering success stories.