Development of Ultrasonically Absorptive Aeroshell Materials for Hypersonic Boundary Layer Transition (BLT) Delay
Navy SBIR 2019.1 - Topic N191-043
ONR - Ms. Lore-Anne Ponirakis - email@example.com
Opens: January 8, 2019 - Closes: February 6, 2019 (8:00 PM ET)
AREA(S): Air Platform, Materials/Processes, Weapons
PROGRAM: Office of Naval Research Code 351: Basic and Applied Research in
technology within this topic is restricted under the International Traffic in
Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and
import of defense-related material and services, including export of sensitive
technical data, or the Export Administration Regulation (EAR), 15 CFR Parts
730-774, which controls dual use items. Offerors must disclose any proposed use
of foreign nationals (FNs), their country(ies) of origin, the type of visa or
work permit possessed, and the statement of work (SOW) tasks intended for
accomplishment by the FN(s) in accordance with section 3.5 of the Announcement.
Offerors are advised foreign nationals proposed to perform on this topic may be
restricted due to the technical data under US Export Control Laws.
Design, fabricate, characterize, and test ultrasonically absorptive aeroshell
materials that successfully damp the second (Mack) mode instability to delay
boundary layer transition (BLT) on hypersonic boost-glide weapons during the
pull-up and glide phases.
Progress has been made over the last two decades in predicting the growth of
the flow instabilities that cause BLT on hypersonic vehicles [Ref 1]. However,
the amplitudes of these disturbances are dependent on the freestream
disturbances [Ref 2]. The magnitude, length scales, and spatiotemporal
distribution of these disturbances in the stratosphere during hypersonic flight
are highly uncertain. In addition, atmospheric particles could also initiate
second mode instabilities, and their distribution and concentration in the
stratosphere is also uncertain and variable. This variability in the
atmospheric disturbances and particles implies that the transition locations on
the vehicle and the altitude at which transition occurs cannot be accurately
predicted. The large uncertainties in BLT lead to conservative aeroshell
designs that penalize flight performance. Boundary layer stabilization using
laminar flow control shows promise in ensuring laminar flow over an extended
flight envelope, even under large uncertainties in the freestream disturbances.
I: Implement the analytical and computational methodologies needed to determine
the porosity characteristics required for typical boost-glide trajectories.
Leverage (as much as possible) existing knowledge and tools from the basic
research conducted over the last 20 years. Employ, in the materials development,
an understanding of the process necessary to make coupon-sized samples of C/C
material with the porosity characteristics (e.g., % open porosity, pore size
and volume distributions) defined by the modeling and simulation portion of the
program. Characterize the material sample by using benchtop experiments to
ensure that the required porosity can be achieved. Include the accurate
fabrication of the intended porosity characteristics as demonstrated by a
rigorous material characterization process.
II: Refine and optimize material processing, characterization techniques, and
analytical and computational methodologies. Produce larger material samples
that can be used for wind tunnel and arcjet testing. Demonstrate ultrasound
damping using benchtop experiments and BLT delay using ground tests under
representative flow conditions. Relevant Mach numbers are between 6 and 10 at
altitudes between 90 and 130 kft. In addition, using arcjet screening of
samples, demonstrate that the mechanical and thermal performance of the
aeroshell material is equivalent to existing ones used on current boost-glide
demonstrators. The conditions achieved during the arcjet tests shall be
representative of flight with enthalpies up to 4.5 MJ/kg at relevant altitudes
(90 to 130 kft).
III DUAL USE APPLICATIONS: Further improve the manufacturing process to improve
performance, reduce fabrication cost, and reduce production time. The aeroshell
performance will ultimately be demonstrated in a flight test experiment when a
sufficient Technology Readiness Level (TRL) is reached. The success criteria
will include the ability of the aeroshell to delay BLT in flight and the
sustainment of the thermal environment. In the near term, this technology is
geared toward military applications, but in the long term, it could be used to
enable commercial hypersonic flight. The ability to maintain a laminar boundary
layer on commercial air platforms will be key to improve the aerodynamic
efficiency and reduce the integrated aerothermal loads. Since such platforms
will most likely be reusable, the reduced heat loads provided by a laminar
boundary layer will be key for allowing reusable (non-ablating) aeroshells.
Fedorov, A. “Transition and Stability of High-Speed Boundary Layers.” Annual
Review of Fluid Mechanics, Vol. 43, 2011. https://www.annualreviews.org/doi/pdf/10.1146/annurev-fluid-122109-160750
Marineau, E. C. "Prediction Methodology for Second-Mode-Dominated
Boundary-Layer Transition in Wind Tunnels." AIAA Journal, Vol. 55, No. 2,
Fedorov, A. V., Malmuth, N. D., Rasheed, A., and Hornung, H. G.
"Stabilization of Hypersonic Boundary Layers by Porous Coatings."
AIAA Journal, Vol. 39, No. 4, 2001. https://pdfs.semanticscholar.org/e7e0/e3d20413a1057d50f804701fda61d16df638.pdf
Rasheed, A., Hornung, H. G., Fedorov, A. V., and Malmuth, N. D.
"Experiments on Passive Hypervelocity Boundary-Layer Control Using an
Ultrasonically Absorptive Surface." AIAA Journal, Vol. 40, No. 3, 2002. https://authors.library.caltech.edu/11341/1/RASaiaaj02.pdf
Wagner, A., Kuhn, M., Martinez Schramm, J., and Hannemann, K. “Experiments on
passive hypersonic boundary layer control using ultrasonically absorptive
carbon–carbon material with random microstructure.” Experiments in Fluids, Vol.
54, 2013. https://link.springer.com/article/10.1007/s00348-013-1606-3
Wagner, A., Kuhn, M., and Hannemann, K. "Ultrasonic absorption
characteristics of porous carbon–carbon ceramics with random microstructure for
passive hypersonic boundary layer transition control." Experiments in
Fluids, Vol. 55, 2014. https://link.springer.com/article/10.1007/s00348-014-1750-4
Laminar Flow Control; Boundary Layer Transition; Hypersonics; Second-mode
Instability; Ultrasonically Absorptive Material; Carbon-carbon (C/C) Aeroshell;
Porous Material; Tactical Boost-glide