Widening the Mach 6 Wind Tunnel Operation Envelope for Hypersonic Propulsion Investigations
Abstract
The recent surge of interest in hypersonic research has spurred a panoply of university scale hypersonic facilities that span a wide range of Mach numbers, enthalpy, Reynolds numbers, and run times. Whereas several short duration facilities can access the flight Reynolds number and enthalpy range, the long duration facilities typically operate at substantially lower Reynolds number and enthalpy barring a very few exceptions. This dichotomy in the operating space has left an array of debilitating long duration flow phenomena in scramjet propulsion systems and external flowfield from being adequately addressed or reliably predicted. With the support of an initiation grant from North Carolina State University and a prior DURIP, a long duration Mach 6 wind tunnel was stood up in the Fall 2022. This wind tunnel facilitates foundational as well as applied hypersonics research and also fills the gap in hypersonic workforce development in Southeast USA as being one of a very few hypersonic facilities in this region. The goals of the proposed DURIP grant are to: 1) upgrade the altitude pressure range of the facility from the current 30 km ? 40 km to 20 km ? 40 km at 60% Mach 6 flight enthalpy; and 2) increase the tunnel test time from the current 10 seconds to approximately 20 seconds. These upgrades will substantially expand the range of vehicle trajectory points that could be studied in this facility and generate validation quality datasets at vehicle relevant conditions, both of which will contribute to advance the predictive capabilities of hypersonic platforms. The facility upgrade will be made using the high pressure high throughput inline electric flow heater requested in this DURIP and other infrastructure that are already available in-house. The near term research objective of the upgraded facility is to demonstrate an axisymmetric morphing scramjet inlet/isolator design to generate adaptive thrust and deepen our understanding of the flow processes that impact the resulting thrust outcome from morphing. The expansion in the flight altitude enabled by the DURIP award will help cover a major portion of the trajectory envelope on the Mach 6 flight. Similarly, the significant improvement in the run time of the facility will uniquely facilitate investigating an array of morphing rates and end states, as well as testing the repeatability of the morphing strategy to reproduce the same end state. In addition, the facility upgrade will allow access to a substantially larger tunnel pressure ratio, which will enable testing complex inlet geometries and intricate morphing approaches that typically produce a larger tunnel blockage compared to simple designs. The findings from the upgraded facility will substantially augment the current effort supported by a cooperative agreement from the Army Research Lab, which seeks to demonstrate the morphing scramjet inlet/isolator concepts and investigate the inlet/ isolator flow processes at various representative trajectory points. In the long term, the upgraded facility is expected to significantly contribute to the DoD hypersonics mission. The activities surrounding this facility will train the future hypersonics workforce in the southeast USA. The outreach activities developed around the facility will have several modules to disseminate research-related education to graduate, undergraduate, and school students. The graduate students working on the project will obtain research training on various DoD projects and mentor the undergraduate research assistants. The PI will also leverage numerous mechanisms to engage undergraduate and graduate students from NCSU and from other HBCU/minority serving universities in North Carolina during and beyond the project term for a wide outreach.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 01, 2023
- Source ID
- W911NF2310374
Entities
People
- Venkateswaran Narayanaswamy
Organizations
- Army Contracting Command
- North Carolina State University
- United States Army