High-quality facilities are critical to success of any experimental research group; one of our hypersonic wind tunnels has recently been completed, while the other is currently in the construction phase and should be operational by mid-2018.
The Hypersonic Tunnel for Educational and Research Purposes (HyperTERP) originally started life as a shock tube built by an intrepid group of undergraduate honors students as a class project. It has since been converted into a reflected shock tunnel equipped with a Mach 6 free-jet nozzle. Run in tailored-interface mode, it is capable of reservoir temperatures and pressures up to approximately 1500 K and 25 atmospheres. It is currently used for testing free-flight articles under hypersonic conditions, and for diagnostic development. In the future this tunnel will also be adapted into a direct-connect configuration for scramjet combustion tests by interchanging the nozzle and test section. The tunnel is supplied by a driver section 3m in length (extendable to 6m for increased test times) and a driven secton 6m in length. The Mach 6 test section measures 48cm x 30cm x 30cm and allows for ready optical access and pressure/temperature measurements of test articles. HyperTERP was completed in Summer 2017.
HAPL has received funding through a DURIP (Defense University Research Instrumentation Program) grant from the Office of Naval Research (ONR) to develop a unique facility for the accurate simulation of hypersonic flows. The Pre-Heated Ludwieg tube with Isentropic Compression (PHLIC) will make use of a pre-heated Ludwieg tube combined with a free-piston compression stage to achieve stagnation temperatures well above those achievable in conventional cold hypersonic tunnels: targeted reservoir conditions are 1850 K and 60 atmospheres, which will be sufficient to accurately simulate Mach 6.5 flight at 27 km altitude. The facility will also be equipped with a Mach 8 nozzle, which will allow larger test articles (nozzle-exit diameter 45 cm, compared to 30 cm at Mach 6.5), though sacrificing the ability to match both flight Mach number and enthalpy simultaneously. The first stage of the PHLIC facility is expected to be operational by mid-2018.
AEDC Hypervelocity Wind Tunnel 9
The Air Force's Tunnel 9 in White Oak is one of the major hypersonic testing and evaluation facilities in the nation. Generating flows up to Mach 14, Tunnel 9 is capable of extremely high Reynolds numbers and has a 5 foot diameter test section, spacious enough for large test articles. Through a formal collaboration between Tunnel 9 and UMD, students may have the opportunity to be involved with diagnostic development and major experimental campaigns in Tunnel 9. Previous and ongoing studies include Mach 10 and 14 boundary-layer transition experiments on a pitching cone, and investigations of Mach 10 turbulent boundary layers and shock-wave/boundary-layer interactions. More information on Tunnel 9 can be found here.
NASA Langley 20-Inch Mach 6 Tunnel
Through a recent collaboration between NASA and the Air Force, HAPL students have had the opportunity to run experiments in the NASA Langley 20-Inch Mach 6 hypersonic wind tunnel in Hampton, VA. A world-premier facility for hypersonic aerothermal testing, the 20-Inch Mach 6 tunnel can achieve flow durations of over 15 minutes and stagnation temperatures exceeding 500 K. Recently, HAPL traveled to Hampton to perform shock-wave boundary-layer interaction and fluid-thermal-structural interaction experiments under a three-year AFOSR grant. More information on NASA Langley hypersonic wind tunnels can be found here.