Practicum Experience(s)
Lawrence Livermore National Laboratory (2025)
Summary of Research
It brings me great joy to study the theory of turbulence. I am fascinated by certain open questions and am interested in developing answers by relying on mathematical analysis, computer simulation, and engagement with experimentalists. Underlying topics that I hope to investigate are high-intensity turbulence, complex flame chemistry, and numerical boundary conditions in the context of direct numerical simulation (DNS).
DNS requires the spatial and temporal scales of turbulent structures to be fully resolved. Even at relatively low Reynolds numbers, DNS calculations can require billion node resolution in the flow field and hundreds of hours compute. Typically, required computational resources scale with the cube of the physical volume of the simulated space. Thus, not only are models expensive, but it is difficult to perform simulations of large, real-world objects. I hope to use approaches in information theory to reduce such demand.
As a submarine officer in the U.S. Navy, I am highly interested in the broad applications of robust turbulence modeling. In the maritime domain, mastery of computational fluid dynamics is critical to maintaining American advantage in nuclear propulsion and undersea warfare. In the context of climate change and an energy crisis, it is evident that continued study of the fundamentals of fluid mechanics will reveal answers. Multi-phase and reacting flows are pertinent in domestic stoves, automotive engines and gas turbines, as well as to nuclear detonations, flow through nuclear cores, and type 1A supernovae.
Annual Program Review Abstracts
Publications
JOURNAL PUBLICATIONS
Walker, M., VanderKam, K., Mueller, M., 2026. "Manifold modeling of flame-flame interactions in turbulent premixed combustion." Proc. Combust. Inst. 42:106064. doi: 10.1016/j.proci.2026.106064
Walker, M., Rzepka, S., Law, C.K., Mueller, M., 2026. "Propagation and corner dynamics of colliding and annihilating premixed flames." Proc. Combust. Inst. 42:000000. doi: 10.1016/j.proci.2026.000000
Walker, M., 2024. "Expanding Non-Cooperative Games for Modern Nuclear Decision-Making." NDC Research Papers Series--29. NATO Defense College. May 2024. Rome, IT.
Walker, M., 2024. "Modeling Escalation Dynamics of Modern Nuclear Decision-Making." On the Horizon: A Collection of Papers from the Next Generation, Vol. 6. Center for Strategic and International Studies (CSIS) Project on Nuclear Issues Report. ISBN: 978-1-5381-7080-9. March 2024. Washington, DC.
Walker, M., 2019. "A Review of Turbulent Burning Velocity and a Spectral Theory for Turbulent Flame Propagation." Master's Thesis, Churchill College, Univ. of Cambridge (UK)., doi: 10.2139/ssrn.4704216
Walker, M., Kelso, R., Bowes, K., Hamilton, L., Luning Prak, D., Cowart, J., 2018. "Partially Premixed Combustion Application for Diesel Power Improvement." ASME. J. Eng. Gas Turbines Power. 140(9):092801-092801-8. doi:10.1115/1.4039809
Walker, M., Krusz, A., 2018. "There's A Case for Diesel." United States Naval Institute Proceedings Magazine. 144(6) 1,384. June 2018. Annapolis, MD.
CONFERENCE PAPERS
Walker, M., Fush, S.T., Mueller, M., 2026. "A Physics-Informed Neural Network for Compressible Rayleigh-Taylor Mixing." 19th International Workshop on the Physics of Compressible Turbulent Mixing. Ann Arbor, MI.
Walker, M., Mueller, M., 2026. "A General Linear Instability Dispersion Relation for Complex, Multi-Physics Hydrodynamic Flows." 19th International Workshop on the Physics of Compressible Turbulent Mixing. Ann Arbor, MI.
Walker, M., Brill, S., Olson, B., 2026. "High-Fidelity Parametric Study of Surface Tension and Viscosity Effects in Immiscible Rayleigh-Taylor Mixing." 19th International Workshop on the Physics of Compressible Turbulent Mixing. Ann Arbor, MI.
Walker, M., Satterthwaite, P., Mueller, M., 2026. "General Transport Equation for Curvature in Premixed Reacting Flows." The Combustion Institute. 2026 ESSCI Spring Technical Meeting 130603373, Raleigh, NC.
Walker, M., VanderKam, K., Law, C.K., Mueller, M., 2025. "Three-Dimensional Topology and Manifold-based Modeling of Turbulent Premixed Flame Annihilation." The Combustion Institute. 14th National Combustion Meeting, Boston, MA.
Walker, M., 2018. "A Partially Premixed Combustion Application for Power Improvement in Military Diesel Engines." Defense Technical Information Center. U.S.N.A. Trident Scholar Project Report; no. 474 (2018), USNA-1531-2.
Walker, M., Hamilton L., Luning Prak, D., Cowart, J., 2018. "Increasing High Load Engine Power with Advanced Combustion Modes." SAE Technical Paper. doi:10.4271/2018-01-0903. Detroit, MI.
Mueller, C., Gehmlich, R., Walker, M., 2018. "An Experimental Study of Diesel-Fuel Property Effects on Mixing-Controlled Combustion in a Heavy-Duty Optical CI Engine." CRC FACE Working Group Meeting. Sandia Technical Report SAND2018-9968PE. Burlingame, CA.
Walker, M., Luning Prak, D. Hamilton, L., Cowart, J., 2018. "High Load Diesel Engine-Generator Power Improvement with Advanced Combustion Modes." The Combustion Institute. 2018 ESSCI Spring Technical Meeting 36IC-0095, State College, PA.
Cowart, J., Bowes, K., Walker, M., Hamilton, L., Luning Prak, D., 2017. "Homogenous Charge Compression Ignition (HCCI) Operation With Jet Fuel and Water Injection in a Single Cylinder Diesel CFR Engine." ASME. Internal Combustion Engine Division Fall Technical Conference, Volume 1: Large Bore Engines; Fuels; Advanced Combustion ():V001T03A016. doi:10.1115/ICEF2017-3653
Bowes, K., Walker, M., Hamilton, L., Luning Prak, D., Cowart, J., 2017. "Homogeneous Charge Compression Ignition (HCCI) Operation with Navy Jet Fuel in a Waukesha Diesel CFR Engine." The Combustion Institute. 10th National Combustion Meeting, College Park, MD.
Awards
Awards
-Naval Submarine League Tactical Excellence Award (2021)
-Winston Churchill Scholarship (2018): Chosen 1 of 15 students nationwide; first graduate of the Naval Academy selected since 1968.
-Chief of Naval Operations Distinguished Graduate Award (2018)
-George H. W. Bush Public Service Scholarship (2015)
Certifications
-Professional Engineer (PE) Mechanical: Thermal and Fluid Systems, licensed in Texas
-Project Management Professional (PMP)
-TOP SECRET (TS/SCI) security clearance