Paul E. Dimotakis
Research interests: fluid physics, dynamics of turbulence, chemically reacting flows, and combustion, measurement technologies and diagnostics development, descending melt-probe planetary exploration of icy worlds.
Overview
Professor Dimotakis focuses on experimental and computational research on turbulent mixing and chemical reactions in subsonic and supersonic free-shear flows; hypersonic propulsion; mixing and the geometry of surfaces and interfaces in turbulence; scalar dispersion in turbulent flows; and related areas.
Space-Related Research
Recent space-related research has been in collaboration with JPL on remote sensing of the atmosphere from space and on the technical feasibility of an asteroid-return mission. Other space-related research has been on high-speed/hypersonic endoatmospheric flight and propulsion, and parachute dynamics for entry, descent, and landing, as well as physics and issues related to a Europa melt-probe to descend through Europa's ice layer to the liquid-water layer.
Related News
Read more newsPublications
Dimotakis, P.E., and D. Lang 2025 Passive-scalar dispersion development and measurements in grid turbulence. Am. Phys. Soc., Div. Fluid Dynamics Meeting (23-25 November 2025, Houston, TX), Interact Session E21:12.
Rollett, A.D., M.K. Brinkley, P.E. Dimotakis, S. Graham, and V. Pugliano 2025 Materials Maturity Levels: A Systematic Approach to Evaluating Materials Development. Integr. Mater. Manuf. Innov. 14:466-481; doi:10.1007/s40192-025-00413-6
Dimotakis, P.E., and D.B. Lang 2023 Liquid-water and solid-ice fields surrounding a descending melt probe. 2023 NASA Cryobot Workshop (21-23 February 2023, California Institute of Technology, Pasadena, CA); doi:10.7907/az3w-xv24.
Sharan, N., G. Matheou, P.E. Dimotakis 2019 Turbulent shear-layer mixing: initial conditions, and direct-numerical and large-eddy simulations. J. Fluid Mech. 877:35-81; doi:10.1017/jfm.2019.591
Luthman, E., N. Cymbalist, D. Lang, G. Candler, and P. Dimotakis 2019 Simulating schlieren and shadowgraph images from LES data. Exp. Fluids 60:134; doi: 10.1007/s00348-019-2774-6.
Sharan, N., G. Matheou, P.E. Dimotakis 2018 Mixing, scalar boundedness, and numerical dissipation in large-eddy simulations. J. Comp. Physics 369:148-172; doi: 10.1016/j.jcp.2018.05.005
Candler, G.V., A. Kartha, P.K. Subbareddy, and P.E. Dimotakis 2018 LES of the Volvo Combustion Experiment with an Ignition-Delay Variable. AIAA Science and Technology Forum and Exposition (7-12 January 2018), Technical Paper PC-08-005.
Candler, G.V., N. Cymbalist, and P.E. Dimotakis 2017 Wall-Modeled Large-Eddy Simulation of Autoignition-Dominated Supersonic Combustion. AIAA J. 55(7):2410-2423; DOI: 10.2514/1.J055550
Gat, I., G. Matheou, D. Chung, D., and P.E. Dimotakis 2017 Incompressible variable-density turbulence in an external acceleration field. J. Fluid Mech. 827:506-535; doi: 10.1017/jfm.2017.490
Matheou, G., and P.E. Dimotakis 2016 Scalar excursions in large-eddy simulations. J. Comp. Physics 327:97–120; http://dx.doi.org/10.1016/j.jcp.2016.08.035
Cymbalist, N., G.V. Candler, and P.E. Dimotakis 2016 Application of the Evolution-Variable Manifold Approach to Cavity-Stabilized Ethylene Combustion. 46th AIAA Fluid Dynamics Conference (13-17 June 2016, Washington, DC), Paper AIAA-2016-3481
Cymbalist, N., and P. Dimotakis 2015 On autoignition-dominated supersonic combustion. Paper AIAA-2015-2315
Kartha, A., P. Subbareddy, G. Candler, and P. Dimotakis 2015 LES of Reacting Mixing Layers: Species Concentration Boundedness and Inflow Conditions. 22nd AIAA Computational Fluid Dynamics Conference, AIAA Paper 2015-3207; doi: 10.2514/6.2015-3207
Kartha, A., P. Subbareddy, G. Candler, and P. Dimotakis 2014 Subgrid-scale chemistry-turbulence interactions in a supersonic mixing layer. 7th AIAA Theoretical Fluid Mechanics Conference, AIAA Aviation and Aeronautics Forum and Exposition (June 2014, Atlanta, GA), Paper AIAA-2014-3030.
Matheou, G., and P.E. Dimotakis 2014 Scalar excursions in large-eddy simulations. 7th AIAA Theoretical Fluid Mechanics Conference (AIAA Aviation meeting), Paper AIAA 2014-3209; http://dx.doi.org/10.2514/6.2014-3209
Dimotakis, P.E., and C. Pantano 2013 Turbulent Combustion. Yearbook of Science & Technology 2013 (McGraw-Hill, ISBN 978-0-07-180140-9), 373-376.
Dimotakis, P.E., L. Chen, Z. Li, S. Licata, E. Olsen, and T. Pagano 2012 Retrieval of vertical T, H2O, O3, and CO2 profiles with sensitivity analysis (SA) and uncertainty quantification (UQ). AIRS Science Team Meeting (24-26 April 2012, Caltech, Pasadena, CA), http://airs.jpl.nasa.gov/documents/science_team_meeting_archive/2012_04/
Dimotakis, P.E., B.C. Walker, K.K. Jonietz, and D.A. Rotman (lead authors) 2011 A Greenhouse-Gas Information System: Monitoring and Validating Emissions Reporting and Mitigation. DOE Office of Science Report, LA-UR 11-05512; doi:10.2172/1033495, http://www.osti.gov/bridge/product.biblio.jsp?query_id=1&page=0&osti_id=1033495.
Ferrante, A., G. Matheou, and P.E. Dimotakis 2011 LES of an inclined sonic jet into a turbulent crossflow at Mach 3.6. Journal of Turbulence 12(2):1-32; doi: 10.1080/14685248.2010.522580.
Bergthorson, J., S. Salusbury, and P.E. Dimotakis 2011 Experiments and modelling of premixed laminar stagnation flame hydrodynamics. J. Fluid Mech. 681:340-369; doi:10.1017/jfm.2011.203.
Eliasson, V., M. Mello, A.J. Rosakis, and P.E. Dimotakis 2010 Experimental investigation of converging shocks in water with various confinement materials. Shock Waves 20:395-408; doi:10.1007/s00193-010-0276-9.
Matheou, G., A.M. Bonanos, C. Pantano, and P.E. Dimotakis 2010 Large-eddy simulation of mixing in a recirculating shear flow. J. Fluid Mech. 646:375-414; doi:10.1017/S0022112009992965.
Matheou, G., D. Chung, J. Teixeira, and P.E. Dimotakis 2010 Application of the stretched-vortex subgrid-scale model to large-eddy simulation of the cloud-topped atmospheric boundary layer. AGU Fall Meeting, Paper A21D-0128.
Eliasson, V., M. Mello, A.J. Rosakis, and P.E. Dimotakis 2010 Experimental investigation of converging shocks in water with various confinement materials. Shock Waves 20:395-408; doi:10.1007/s00193-010-0276-9.
Matheou, G., A.M. Bonanos, C. Pantano, and P.E. Dimotakis 2010 Large-eddy simulation of mixing in a recirculating shear flow. J. Fluid Mech. 646:375-414; doi:10.1017/S0022112009992965.
Dimotakis, P.E., D.B. Lang, S. Lombeyda, J. Lindheim 2009 An Investigation of Scalar Dispersion in Grid Turbulence. In: Zhuang, F.G., Li, J.C. (eds) New Trends in Fluid Mechanics Research (15-19 August 2007, Shanghai, China). Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-75995-9_2
Bond, C., D. Hill, D. Meiron, and P.E. Dimotakis 2009 Shock focusing in a planar convergent geometry: experiment and simulation. J. Fluid Mech. 641:297-333; doi: 10.1017/S0022112009991492.
Bonanos, A.M., J.M. Bergthorson, and P.E. Dimotakis 2009 Molecular mixing and flowfield measurements in a recirculating shear flow. Part II: supersonic flow. Flow, Turb. & Combustion 83:251–268; doi:10.1007/s10494-009-9199-x
Dimotakis, P.E., 2008 Global Change & Energy: A Path Forward. Engineering & Science LXXI(4):12-19; http://pr.caltech.edu/periodicals/EandS/articles/LXXI4/Dimotakis-web2.pdf (California Institute of Technology, Pasadena, CA).
Benezech, L.J., J.M. Bergthorson, and P.E. Dimotakis 2008 Premixed laminar C3H8- and C3H6-air stagnation flames: experiments and simulations with detailed kinetic models. Proc. Comb. Institute 32:1301-1309.
Chahine, M.T., L. Chen, P. Dimotakis, X. Jiang, Q. Li, E.T. Olsen, T. Pagano, J. Randerson, and Y.L. Yung 2008 Satellite remote sounding of mid-tropospheric CO2. Geophysical Res. Lett. 35:L17807; doi:10.1029/2008GL035022.
Pantano, C., D.I. Pullin, P.E. Dimotakis, and G. Matheou 2008 LES approach for high Reynolds number wall-bounded flows with application to turbulent channel flow. J. Comp. Physics 227:9271-9291; doi:10.1016/j.jcp.2008.04.015.
Gunapala, S.D., P.E. Dimotakis, S.V. Bandara, and D.W. Wilson 2008 High Performance Polarization Sensitive Detector Array. Jet Propulsion Laboratory NTR 45932, California Institute of Technology (22-Feb-08).
Bergthorson, J.M., M.B. Johnson, A.M. Bonanos, M.D. Slessor, W. Su, and P.E. Dimotakis 2008 Molecular mixing and flowfield measurements in a recirculating shear flow. Part I: subsonic flow. Flow, Turbulence, and Combustion 83:269-292.
Benezech, L.J., J.M. Bergthorson, and P.E. Dimotakis 2008 Premixed laminar C3H8- and C3H6-air stagnation flames: experiments and simulations with detailed kinetic models. Proc. Comb. Institute 32:1301-1309.
Bonanos, A.M., J.M. Bergthorson, and P.E. Dimotakis 2008 Mixing measurements in a supersonic expansion-ramp combustor. Flow, Turbulence & Combustion 80:489-506; doi:10.1007/s10494-008-9133-7.
Chahine, M.T., L. Chen, P. Dimotakis, X. Jiang, Q. Li, E.T. Olsen, T. Pagano, J. Randerson, and Y.L. Yung 2008 Satellite remote sounding of mid-tropospheric CO2. Geophysical Res. Lett. 35:L17807; doi:10.1029/2008GL035022.
Matheou, G., C. Pantano, and P.E. Dimotakis 2008 Verification of a fluid-dynamics solver using correlations with linear stability results. J. Comp. Physics 227:5385-5396; doi: 10.1016/j.jcp.2008.01.055.
Pantano, C., D.I. Pullin, P.E. Dimotakis, and G. Matheou 2008 LES approach for high Reynolds number wall-bounded flows with application to turbulent channel flow. J. Comp. Physics 227:9271-9291; doi:10.1016/j.jcp.2008.04.015.
Bergthorson, J.M., and P.E. Dimotakis 2007 Premixed laminar C1-C2 stagnation flames: experiments and simulations with detailed thermochemistry models. Proc. Comb. Institute 31:1139-1147; doi:10.1016/j.proci.2006.07.110
Bonanos, A., J. Bergthorson, and P. Dimotakis 2007 Molecular Mixing and Flowfield Measurements in an Expansion-Ramp Combustor: Supersonic Flow. 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference. Paper AIAA-2007-5417; doi:10.2514/6.2007-5417
Shan, J.W., and P.E. Dimotakis 2006 Reynolds-number effects and anisotropy in transverse-jet mixing. J. Fluid Mech. 566:47-96.
Dimotakis, P.E., and R. Samtaney 2006 Planar shock cylindrical focusing by a perfect-gas lens. Phys. Fluids 18(3):031705; doi:10.1063/1.2186553.
Bergthorson, J.M. and P.E. Dimotakis 2006 Particle velocimetry in high-gradient/high-curvature flows. Exp. Fluids 41(2):255-263; doi:10.1007/s00348-006-0137-6.
Bergthorson, J.M., K. Sone, T.W. Mattner, P.E. Dimotakis, D. Goodwin, and D. Meiron 2005 Impinging laminar jets at moderate Reynolds numbers and separation distances. Phys. Rev. E 72(6):066307.
Kern, B., P.E. Dimotakis, C. Martin, D.B. Lang, and R.N. Thessin 2005 Imaging through turbulence with a quadrature-phase optical interferometer. Applied Optics 44(34):7424-7438. ISSN 0003-6935. http://resolver.caltech.edu/CaltechAUTHORS:KERao05
Dimotakis, P.E., 2005 Turbulent Mixing. Ann. Rev. Fluid Mech. 37:329–356.
Bergthorson, J.M., D.G. Goodwin, and P.E. Dimotakis 2004 Particle streak velocimetry and CH laser-induced fluorescence diagnostics in strained premixed methane-air flames. Proc. Combustion Inst. 30:1637–1644; doi: 10.1016/j.proci.2004.08.105
Shan, J.W., and P.E. Dimotakis 2004 Scalar concentration measurements in liquid-phase flows with pulsed lasers. Exp. Fluids 36:268–273; doi:10.1007/s00348-003-0717-7
Bergthorson, J.M., D.G. Goodwin, and P.E. Dimotakis 2004 Experiments and modeling of impinging jets and premixed stagnation flames. Proc. 15th Australasian Fluid Mech. Conf. http://www.aeromech.usyd.edu.au/15afmc, Paper AFMC00087.
Hill, D., T.W. Mattner, C. Pantano, A.W. Cook, P.E. Dimotakis, D.I Meiron, and D.I Pullin 2003 Computational study of turbulent mixing at the Caltech ASC center. AIAA 34nd Plasmadynamics and Lasers Conference, AIAA Paper 2003–3696.
Kern, B., P.E. Dimotakis, D.B Lang, C. Martin, and R.N. Thessin 2003 Aberrating medium characterization and image reconstruction with a quadrature phase interferometer. AIAA 34nd Plasmadynamics and Lasers Conference, AIAA Paper 2003–3610.
Papalexandris, M.V., A. Leonard, and P.E. Dimotakis 2002 Unsplit algorithms for multi-dimensional systems of hyperbolic conservation laws with source terms. Comp. & Math. w. Applications 44:25–49; doi:10.1016/S0898-1221(02)00128-1
Cook, A.W., and P.E. Dimotakis 2001 Transition stages of Rayleigh-Taylor instability between miscible fluids. J. Fluid Mech. 443:69–99.
Dimotakis, P.E., H.J. Catrakis, and D.C. Fourguette 2001 Flow structure and optical beam propagation in high Reynolds number, gas-phase shear layers and jets. J. Fluid Mech. 433:105–134.
Kern, B., D.B. Lang, C. Martin, P.E. Dimotakis, and M. Wadsworth 2001 A high-speed quadrature-phase rotation-shearing interferometer for imaging through turbulence. AIAA 32nd Plasmadynamics and Lasers Conference, AIAA Paper 2001–2797.
Kern, B., T.A. Laurence, C. Martin, and P.E. Dimotakis 2000 Temporal coherence of individual turbulent patterns in atmospheric seeing. Appl. Optics 39(27):4879–4885.
Dimotakis, P.E., 2000 The mixing transition in turbulent flows. J. Fluid Mech. 409:69–98.
Dimotakis, P.E., and P.L. Miller 1990 Some consequences of the boundedness of scalar fluctuations. Phys. Fluids A 2(11):1919-1920; doi: 10.1063/1.857666
Dimotakis, P.E., 1974 Gorter-Mellink Scale and Critical Velocities in Liquid-Helium-II Counterflow. Phys. Rev. A 10(5):1721–1723 [Identified dimensionless number was subsequently named the "Dimotakis number"].