NRC Research and Fellowship Programs
Fellowships Office
Policy and Global Affairs

Participating Agencies

  sign in | print

RAP opportunity at Air Force Science and Technology Fellowship Program     AF STFP

Rapid Time Dependent Non-Linear Predictive Method to Model Cavity Resonance


Aerospace Systems Directorate, RQ/Aerospace Vehicles Division

opportunity location
13.30.09.C0914 Wright-Patterson AFB, OH 454337103


name email phone
Ryan Frank Schmit 937-7136688


When flow passes over a cavity, the fluidic response creates a time dependent non-linear dynamic feedback mechanism1.  The cavity shear layer generates and attenuates the acoustic and hydrodynamic waves that dominate the cavity.  The waves motion creates the resonate frequencies and amplitudes that have historically been called Rossiter modes.  Rossiter Equation is valid for limited cases and a more robust understanding of the underlying cavity physics is required. To validate our understanding of the cavity physics, one method is to produce a robust cavity model capable of modeling the time dependent non-linear dynamics seen in experimental2 and computational work.  Integrating flow control methods, passive or active, pose a challenge by modifying the cavity shear layer.  By developing a predictive method that efficiently models the shear layer physics and flow control effects, cavity physics can be accounted for in the rapid design of future aircraft platforms.

Areas of interest include: (1) incoming boundary layer-cavity shear layer transition; (2) cavity shear layer development; (3) cavity acoustic and hydrodynamic wave generation and attenuation; (4) time dependence and non-linear dynamic interactions; (5) develop a cavity model to be utilize by aircraft designers in trade studies; (6) numerical or experimental validation of cavity model; (7) methods to implement or modify the base line cavity to improve desired outcome.  Research would involve developing a numerical model and associated software integration, and could include experimental modeling, computational modeling, analytical modeling, data base development, and/or new flow control methodologies.

1. Schmit, R. F., Grove, J. E., Semmelmayer, F., Haverkamp M., (2014) “The Nonlinear Feedback Mechanisms inside a Rectangular Cavity”, AIAA Journal, Vol. 52 No10, p 2127-2142

2. Flaherty, W., Reedy, T. M., Elliott G. S., Austin J. M., Schmit R. F., and Crafton J., (2014) “Investigation of Cavity Flow Using Fast-Response Pressure Sensitive Paint”, AIAA Journal, Vol. 52, No. 11, p 2462-2470


key words
Cavity, Non-Linear Dynamics, Acoustic, Shear Layer, Numerical Methods


Citizenship:  Open to U.S. citizens
Level:  Open to Postdoctoral and Senior applicants


Base Stipend Travel Allotment Supplementation
$95,000.00 $5,000.00

Experience Supplement:
Postdoctoral and Senior Associates will receive an appropriately higher stipend based on the number of years of experience past their PhD.

Copyright © 2024. National Academy of Sciences. All rights reserved.Terms of Use and Privacy Policy