16T wind tunnel systems receive significant upgrade
By Bradley Hicks, AEDC/PA
/ Published July 03, 2018
ARNOLD AIR FORCE BASE, Tenn. --
Demand for the transonic testing capabilities offered by Propulsion Wind Tunnel 16T is expected to remain strong for the foreseeable future.
Because of this, a multimillion dollar effort was launched this fiscal year at 16T to increase testing efficiency, provide greater accessibility to critical testing instrumentation systems, and improve facility software and data displays.
The upgrade consisted of two parallel efforts aimed at improving data acquisition and test control systems that are mounted to the two large removable test carts used in 16T. By design, these carts are installed in the tunnel during testing and become an integral part of the test section that holds the test model. Hence, all equipment on the carts must survive the strenuous conditions that exist during testing.
During the first phase, which was completed after the first of the year, a new Data Acquisition System (DAS) and Test Article Control System (TACS) was installed for the 16T High Angle Automated Sting (HAAS) testing cart. As their names imply, the DAS is responsible for the collection of testing data while the TACS is used to control the test itself, such as setting the position of a test article within the tunnel airflow. The second phase of the two-pronged effort – installation of the improved DAS and TACS system on a sister Multipurpose Test Cart – was recently completed.
Work on the HAAS cart was completed in January.
Due to harsh conditions present in the tunnel while testing is ongoing, the computer units, which are physically mounted to the test carts where models are attached, are housed in large metal boxes or enclosures. New improved enclosures were built for both carts, each having new temperature- and pressure-control systems. The upgraded enclosures not only provide continued protection from the testing elements, but according to PWT Section Leader Peter Macaluso, they also provide improved access to the recently-updated computers should engineers need to make adjustments. The old enclosures took around 20 minutes to get into, while equipment contained within the new enclosures can be accessed in about 5 minutes.
The computers also received new wiring, as well as an update to Windows 10. Encoders were also updated.
Phase two will complete with the verification of the 16T Multipurpose Cart. Verification testing was completed in mid-April and a final verification decision is imminent. Like the HAAS, a new DAS and TACS has been installed for this cart. These units also received new environmental enclosures, as well as wiring and computer network capability updates. The Multipurpose Cart also received additional upgrades to encoders used to measure the multi-directional movement of the Captive Trajectory Support system, and new high-definition cameras were added on the cart arm to capture store motion.
The HAAS Cart will be receiving an upgrade to its optical flow visualization capabilities within the coming months.
The data system and model control systems were also updated for a third testing Cart that will be used exclusively in PWT 16S once it returns to service. That tunnel is scheduled to again become operational in early 2019.
PWT 16T offers aerodynamic, propulsion, integration and weapons test capabilities. Each test cart provides a 16-foot square by 40-foot long test section and can accommodate large-scale test models. The facility allows for testing at Mach numbers 0.05 to 1.60.
The project to upgrade the 16T testing carts was slated for completion in the 2019 fiscal year, meaning the upgrades were completed a year ahead of schedule.
The last upgrade at 16T prior to the most recent effort occurred approximately 15 years ago.
Macaluso added that having the new systems and equipment in place will lead to more time for customer testing at 16T due to less time spent on troubleshooting.
“It has been no surprise to us that the workload in test is increasing,” he said. “It is work coming from all directions, and that allows us to keep our skills sharp and helps us maintain our position as the nation’s ground test facility of choice. Our expertise, data analysis capabilities, and improved systems allow for increased efficiency, higher reliability, and improved data accuracy for our customers.”