Phone: 979.862.2323 ext. 115
Texas A&M University
833 Graham Road
College Station, Texas 77845
Dr. Joseph Kuehl
Assistant Research Scientist
Ph.D. Mechanical Engineering, University of Rhode Island, 2009
Bachelor of Science Physics, Michigan Technological University, 2004
- Physical Oceanography (Geophysical Fluid Dynamics)
- Aerospace Engineering (Hypersonic Boundary Layer Stability)
- Mechanical Engineering (Nonlinear Vibrations)
Research concerning geophysical gap-leaping boundary currents (loop-currents). The idealized situation of a predominantly inertial boundary current impinging on a gap was investigated by rotating table laboratory experiments. Findings are confirmed for both single- and two-layer experiments as well as supported by numerics and theory. Key contributions:
- Confirm the hypothesis of Sheremet (2001), that variations in the inertia of the current can cause transitions between states and that there is a hysteresis associated with those transitions.
- When a two-dimensional parameter space, representing the current's inertia (promotes gap-leaping) and vorticity constraints (promotes gap-penetrating) of the system, is considered, the system admits a cusp catastrophe geometry of solutions.
- Penetrating states may be steady or periodic eddy-shedding based on the balance between vorticity advection and dissipation.
- A physics based condition for prediction of the leaping-to-penetrating transition was proposed in good agreement with experimental observations.
Research concerning the laminar-turbulent transition process for aerospace boundary layer applications, particularly hypersonic flows. This research is centered around the development of a nonlinear Parabolized Stability Equations code (JoKHeR), which has been validated against quiet hypersonic wind tunnel experiments and existing literature. Key contributions:
- Development of JoKHeR NPSE code.
- Identification of ``vortex line'' marching paths for hypersonic crossflow instabilities. These paths are found to be consistent with observed crossflow vortices and dramatically influence stability calculations.
- Identification of ``nonlinear coupling coefficients'' via convolution integrals in the parabolized stability equations method. These coefficient are necessary to correctly account for nonlinear flow of energy between modes and mean flow in real situations (when finite-width frequency band disturbance are considered).
- Discovery of the ``nonlinear detuning'' of second mode instabilities in hypersonic flows. This is a negative feedback mechanism by which the most unstable second mode frequency will shift towards lower frequencies. Understanding of such nonlinear mechanisms are important for laminar-turbulent control efforts.
Research concerning the generalization of invariant manifold concepts to finite-time, with emphasis on identification of basins of attraction in nonlinear vibrational systems where only phase space trajectory data is available. Focus was placed on detection ability, data requirements, and noise sensitivity for numerically simulated experimental data of the damped driven two-well Duffing equation and confirmed with Moon's Beam experimental data. Key contribution:
- Development of the Phase Space Warping (PSW) method for manifold detection. Manifold detection methods generally consider a trajectory's sensitivity to initial position, however the PSW method takes advantage of sensitivity to other system parameter.
- R/V Ferrell Cruise, August 2012. Texas Automated Buoy System (TABS) buoy deployment/recovery cruise. TABS I, TABS II and 2.25 meter discuss buoys were replaced at part of the TABS scheduled maintenance. In addition, a short test deployment of the Responder buoy was conducted.
- R/V Pelican Cruise PE-1301, July 2012. GISR mooring deployment cruise. Deployment of 6 moorings around the Deepwater Horizon oil spill site and hydrographic sampling of the surrounding area.
- R/V Endeavor Cruise 440, October 2007. Line W cruise. Hydrographic sampling across the deep western boundary current off the New England coast.
- R/V Endeavor Cruise 400, December 2005. Investigation of shelf break front with towed instrument and ADCP.
- Kocian, T. S., E. Perez, N. B. Oliviero, J. Kuehl, H. L. Reed, (2013). "Hypersonic Stability Analysis of a Flared Cone,'' AIAA-2013-667.
- Hofferth, J. W., S. W. Saric, J. Kuehl, E. Perez, T. Kocian, H. L. Reed, (2013). "Boundary-Layer Instability & Transition on a Flared Cone in a Mach 6 Quiet Wind Tunnel,'' International Journal of Engineering Systems Modelling and Simulation, 5 (1/2/3), 109-124.
- Perez, E., T. S. Kocian, J. Kuehl, H. L. Reed, (2012). "Stability of Hypersonic Compression Cones,'' AIAA-2012-2962.
- Hofferth, J. W., S. W. Saric, J. Kuehl, E. Perez, T. Kocian, H. L. Reed, (2012). "Boundary-Layer Instability & Transition on a Flared Cone in a Mach 6 Quiet Wind Tunnel,'' RTO/AVT Specialists Meeting on Hypersonic Laminar-Turbulent Transition : AVT-200/RSM-030, San Diego, CA, USA. Paper No. 10.
- Reed, H. L., J. Kuehl, E. Perez, T. Kocian, J. W. Hofferth, S. W. Saric, (2012). "Nonlinear Parabolized Stability Equation Simulations in Hypersonic Flows,'' RTO/AVT Specialists Meeting on Hypersonic Laminar-Turbulent Transition : AVT-200/RSM-030, San Diego, CA, USA. Paper No. 7.
- Hofferth, J. W., S. W. Saric, J. Kuehl, E. Perez, T. Kocian, H. L. Reed, (2012). "Comparison of Experimental and Computational Boundary-Layer Profiles and Instability Growth on a Flared Cone in a Mach 6 Quiet Flow,'' 3AF 47th Inter-national Symposium of Applied Aerodynamics, Paris, France. Paper No. 37.
- Kuehl, J., E. Perez, and H. L. Reed, (2012). “JoKHeR: NPSE Simulations of Hypersonic Crossflow Instability,” AIAA-2012-0921.
- Kuehl, J., and D. Chelidze, (2010). “Identifying invariant manifolds using phase space warping and stochastic interrogation,” International Journal of Non-linear Mechanics, 45 (1), 42-55.
- Kuehl, J., and V.A. Sheremet, (2009). “Identification of Cusp Catastrophe in Gap Leaping Western Boundary Current Problem,” Journal of Marine Research, 37 (1), 25-42.
- Kuehl, J., and D. Chelidze, (2008). “Invariant Manifold Identification from Phase Space Trajectories,” ASME International Mechanical Engineering Congress and Exposition, Boston, MA (11/08) Technical Paper (IMECE2008-67473).
- Sheremet, V.A., and J. Kuehl, (2007). “Gap leaping western boundary current in a circular tank model,” Journal of Physical Oceanography, 37, 1488-1495.
- Kuehl, J., and P. Cornillon, (2003). “Evolution of Laboratory Generated, Velocity Shear Fronts”. Summer Undergraduate Research Fellowship Pro- gram In Oceanography, 2003. Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, GSO Technical Report 2004-01.