Tunnel 9 staying in high demand

October marks the 20th anniversary of the Hypervelocity Wind Tunnel 9 as an Air Force facility. Tunnel 9, located at White Oak, Maryland near Silver Spring, became operational in 1976. The facility provides aerodynamic simulation critical to the development of hypersonic systems, including critical altitude regimes associated with strategic missile systems and advanced defensive interceptor systems, and hypersonic vehicle technologies. (AEDC file photo)

Tunnel 9, located at White Oak, Maryland near Silver Spring, became operational in 1976. The facility provides aerodynamic simulation critical to the development of hypersonic systems, including critical altitude regimes associated with strategic missile systems and advanced defensive interceptor systems, and hypersonic vehicle technologies. (AEDC file photo)

ARNOLD AIR FORCE BASE, TENN. -- The prediction made years ago by the team at AEDC Hypervelocity Wind Tunnel 9 in White Oak, Maryland, has come to fruition, and their forecast of an increased workload was on point.

For the past several years, Tunnel 9 has been running at near to capacity. Tunnel 9 Director Dan Marren said the recent uptick in facility activity can be heavily attributed to what he described as currently the “hottest ticket” in aerospace – hypersonics.

“In 2005, we predicted that the demand signal for hypersonics would begin in 2010,” Marren said. “Since 2010, we have seen a steady increase in testing culminating in the last three years of capacity testing.”

Hypersonic is the term used for speeds of Mach 5 or greater.

Tunnel 9 runs a single shift, meaning the team is able to complete 150 to 200 tests per year with the current staff.

Hypersonics projects with which Tunnel 9 has recently been involved include offensive boost glide reentry, defensive missile defense programs and targets, and helping NASA and their commercial space partners develop the next generation of vehicles.

“We have also led the way on advancing our understanding of physics and phenomenon that drive hypersonic challenges,” Marren said.

Tunnel 9 offers features that other facilities cannot. Marren explained that Tunnel 9 is the largest pressure, highest Reynolds number, facility in the world. Because of this, the Tunnel 9 team can currently provide testing through Mach 14 and provide realistic flight representative data on large-scale to full-scale test articles.

Running at near or full capacity has presented both benefits and challenges. On one hand, the Tunnel 9 team has had the opportunity to apply their knowledge and skills to a variety of tests, learning along the way. On the other hand, the sustained testing has left fewer opportunities to address other items impacting Tunnel 9.

“It has had both good and bad effects,” Marren said. “The bad are that we increasingly are finding it difficult to find time for everything a facility will have to do to remain viable - maintenance, investments, training, and just crew rest becomes ever increasingly hard.

“On the positive side, our team has seen every aspect of test, sees new challenges daily, and is continuing to hone skills to remain the best crew in the nation regarding hypersonic test.”