Ugo Piomelli PhD, FRSC, FAPS, FASME, FCAE

Professor

Faculty, Mechanical and Materials Engineering
Fax: 613-533-6489
McLaughlin Hall, Room: 228


Expertise: Large eddy and direct simulations, Turbulence simulations and modelling, Transition modelling, Computational fluid dynamics, Geophysical flows
Ugo Piomelli
Biography Research Publications

Academic: 

Department of Mechanical and Materials Engineering, Queen's University  
  • Professor (August 2008-Present) 
  • Tier I Canada Research Chair in Turbulence Simulaiton and Modelling (2008-2022)
  • HPCVL-Sun Microsystem Chair in Computational Science and Engineering (2008-2015)
Department of Mechanical Engineering, University of Maryland  
  • Professor (July 2000-July 2008) 
  • Associate Chair (July 2002-July 2006) 
  • Associate Professor (July 1993) 
  • Assistant Professor (December 1987)

Education: 

Fellowships: 

  • American Physical Society (APS), Fellow, 2002. 
  • American Institute of Aeronautics and Astronautics (AIAA),  Associate Fellow, 2004. 
  • American Society of Mechanical Engineers (ASME), Fellow, 2009. 
  • Royal Society of Canada (RSC), Fellow, 2015. 
  • Canadian Academy of Engineering (CAE), Fellow, 2021

Research Interests  

  • Large eddy and direct simulations 
  • Turbulence simulations and modelling 
  • Transition modelling 
  • Computational fluid dynamics 
  • Geophysical flows 
  • Bio fluid dynamics 

 

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Watch the 2019 John Adjeleian Lecture:  
The good, the bad and the beautiful:  
Leonardo's studies of turbulence.  
Carleton University, April 10, 2019. 

Nota il moto del livello dell'acqua, il quale fa a uso de' capelli, che ànno due moti, de' quali l'uno attende al peso del vello, l'altro al liniamento delle volte; cosí l'acqua à le sue volte revertiginose, delle quali una parte attende al impeto del corso principale, l'altra attende al moto incidente e riflesso. 
Observe the motion of the water surface, which resembles that of hair, that has two motions: one due to the weight of the shaft, the other to the shape of the curls; thus, water has eddying motions, one part of which is due to the principal current, the other to the random and reverse motion. 

Leonardo da Vinci, ca. 1510 

What is LES? 

The prediction and control of fluid flows over solid bodies is very important from a technological point of view: both the performance and observability of aircraft, surface or submerged vessels, or automobiles, for instance, are very much affected by the flow patterns around the body itself. In many instances, in fact, the aerodynamic (or hydrodynamic) loads are the main source of noise, drag or unsteadiness. 

The main obstacle in the prediction of flows is the presence of turbulent motions. These motions can be calculated quite accurately by a numerical solution of the complete set of equations of motion, the Navier-Stokes equations, albeit at costs that are prohibitively high, except for very simple configurations in conditions quite different from those encountered in realistic applications. Any simplified model developed so far, although applicable in realistic cases, requires ad hoc adjustments that are case-dependent. This is due to the fact that turbulent motions in general are strongly affected by the flow configuration, and cannot be reliably described by universal models. 

It has been observed, however, that the smallest turbulent motions are more universal than the large ones. If one could develop reliable models for the small turbulent eddies, the numerical solution of the Navier-Stokes equations would be greatly simplified, and its cost decreased by several orders of magnitude. 

These considerations form the foundations of, and the motivation for, the technique known as large-eddy simulation (LES). In LES the small turbulent eddies are modeled, and only the motion of the large ones is computed numerically. LES may very well be the only technique capable of predicting some particularly complex flows, especially if three-dimensional effects or unsteadiness are present in the mean. 

 

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Journal articles (since 2014)

  • F. Ambrogi, U. Piomelli, and D. E. Rival. Influence of time-varying freestream conditions on the dynamics of unsteady boundary-layer separation. In press AIAA J., 2024. https://doi.org/10.2514/1.J064382
  • Z. Hantsis and U. Piomelli. Numerical simulations of scalar transport on rough surfaces. Fluids, 9(159):1–31, 2024.
  • R. Garcıa-Mayoral, D. Chung, P. Durbin, N. Hutchins, T. Knopp, B. J. McKeon, U. Piomelli, and R.D. Sandberg. Challenges and perspective on the modelling of high-re, incompressible, non-equilibrium, rough-wall boundary layers. In press  J. Turbul., 0(0):2361738–1–27, 2024. https://doi.org/10.1080/14685248.2024.2361738
  • R. J. Volino, D. Fritsch, W. J. Devenport, L. Eca, R. Garcıa-Mayoral, B. J. McKeon, U. Piomelli, D. Chung, V. Vishwanathan, M. Kerkvliet, S. Toxopeus, and N. Hutchins. Effects of roughness on non-equilibrium turbulent boundary layers. In press  J. Turbul., pages 1–17, 2024. https://doi.org/10.1080/14685248.2024.2360186
  • F. Ambrogi, U. Piomelli, and D. E. Rival. Characterization of unsteady separation in a turbulent boundary layer: Reynolds stresses and flow dynamics. J. Fluid Mech., 972(A36):1–24, 2023.
  • V. Kumar, A. Miro, O. Lehmkuhl, and U. Piomelli. Flow separation in airfoils with rough leading-edges. AIAA J., 61(5):2035–2047, 2023.
  • C. Y. MacDougall, U. Piomelli, and F. Ambrogi. Evaluation of turbulence models in unsteady separation. Fluids, 8(273):1–17, 2023.
  • T. Salomone, U. Piomelli, and G. De Stefano. Large-eddy simulations of the flow over roughness strips. Fluids, 8(10):1–16, 2023.
  • F. Ambrogi, U. Piomelli, and D. E. Rival. Characterization of unsteady separation in a turbulent boundary layer. J. Fluid Mech., 945(A10):1–30, 2022.
  • Z. Hantsis and U. Piomelli. Effects of roughness on the turbulent Prandtl number, time-scale ratio and dissipation of a passive scalar. Phys. Rev. Fluids, 7(124601):1–24, 2022.
  • M. Teng and U. Piomelli. Instability and transition of a boundary layer over a backward-facing step. Fluids, 7(35):1–18, 2022.
  • R. J. Volino, W. J. Devenport, and U. Piomelli. Questions on the effects of roughness and its analysis in non-equilibrium flows. J. Turbul., 23(8):454–466, 2022.
  • G. D’Alessandro, Z. Hantsis, C. Marchioli, and U. Piomelli. Accuracy of bed-load transport models in eddy-resolving simulations. Int. J. Multiphase Flow, 141:103676–1–16, 2021. 
    doi: https://doi.org/10.1016/j.ijmultiphaseflow.2021.103676 
  • B. J. Geurts, A. Rouhi, U. Piomelli. Recent progress on reliability assessment of large-eddy simulation. J. Fluids Struct., 91(102615):1–13, 2019.  
    doi: https://doi.org/10.1016/j.jfluidstructs.2019.03.008    , 2019. 
  • O. Lehmkuhl, U. Piomelli, and G. Hozeaux. On the extension of the integral length-scale approximation model to complex geometries. Int. J. Heat Fluid Flow, 78(108422):1–12, 2019. doi:10.1016/j.ijheatfluidflow.2019.108422 
  • M. Mellati Nokhandan, U. Piomelli, and M. Omidyeganeh. Large-eddy and wall-modelled simulations of turbulent flow over two-dimensional river dunes. Phys. Chem. Earth, 113:123–131, 2019.  
    doi: https://doi.org/10.1016/j.pce.2018.11.004 
  • Rodrıguez, O. Lehmkuhl, U. Piomelli, J. Chiva, R. Borell, and A. Oliva. LES-based study of the roughness effects on the wake of a circular cylinder from subcritical to transcritical Reynolds numbers. Flow, Turb. Combust., 99:729–763, 2017. doi: 10.1007/s10494-017-9866-2 
  • W. Wu and U. Piomelli. Effects of surface roughness on a separating turbulent boundary layer. J. Fluid Mech., 841:552–580, 2018. doi:10.1017/jfm.2018.101 
  • W. Wu, G. Soligo, C. Marchioli, A. Soldati, and U. Piomelli. Particle resuspension by a periodically forced impinging jet. J. Fluid Mech., 820:284–311, 2017. doi:10.1017/jfm.2017.210 
  • R. Dutta, J. Nicolle, A.-M. Giroux, and U. Piomelli. Evaluation of turbulence models in rough-wall boundary layers for hydroelectric application. Int. J. Fluid Mach. Sys., 10(3):228–239, 2017. doi:10.5293/IJFMS.2017.10.3.227 
  • Rouhi, U. Piomelli, and B. J. Geurts. A dynamic subfilter-scale stress model for large eddy simulations. Phys. Rev. Fluids, 1(4):044401–1–26, 2016. doi:10.1103/PhysRevFluids.1.044401 
  • W. Wu, R. Banyassady, and U. Piomelli. Large-eddy simulation of impinging jets on smooth and rough surfaces. J. Turbul., 17(7):1–23, 2016. doi:10.1080/14685248.2016.1181761 
  • W. Wu and U. Piomelli. Reynolds-averaged and wall-modelled large-eddy simulations of impinging jets with embedded azimuthal vortices. Eur. J. Mech. B: Fluids, 55, part 2:348–359, 2016. doi:10.1016/j.euromechflu.2015.06.008 
  • W. Wu, U. Piomelli. Reynolds-averaged and wall-modelled large-eddy simulations of impinging jets with embedded azimuthal vortices. European J. Mech./B Fluids, 55, part 2:348–359, 2016. http://dx.doi.org/10.1016/j.euromechflu.2015.06.008 
  • J. Yuan and U. Piomelli. Numerical simulations of accelerating boundary layers over roughness. J. Fluid Mech., 780:192–214, 2015. http://dx.doi.org/10.1017/jfm.2015.437 
  • Jabbari, L. Boegman, and U. Piomelli. Evaluation of the inertial dissipation method within boundary layers using numerical simulations. Geophys. Res. Lett., 42:1504–1511, 2015. http://dx.doi.org/10.1002/2015GL063147. 
  • U. Piomelli, A. Rouhi, and B. J. Geurts. A grid- independent length scale for large-eddy simulations. J. Fluid Mech., 766:499–527, 2015. http://dx.doi.org/10.1017/jfm.2015.29. 
  • Silva Lopes, J. M. L. M. Palma, and U. Piomelli. On the determination of effective roughness of surfaces with vegetation patches. Bound.-Lay. Meteorol., 156:113–131, 2015. http://dx.doi.org/10.1007/s10546-015-0022-z 
  • Skillen, A. Revell, A. Pinelli, U. Piomelli, and J. Favier. Flow over a wing with leading-edge undulations. AIAA J., 53(2):464–472, 2015. http://dx.doi.org/10.2514/1.J053142 
  • W. Wu, U. Piomelli. Large-eddy simulation of impinging jets with embedded azimuthal vortices. J. Turbul., 16(1):44–66, 2014.   http://dx.doi.org/10.1080/14685248.2014.957383 
  • J. Yuan and U. Piomelli. Roughness effects on the Reynolds stress budgets in near-wall turbulence. J. Fluid Mech., 760:R1–1–12, 2014. http://dx.doi.org/10.1017/jfm.2014.608 
  • R. Banyassady and U. Piomelli. Turbulent plane wall-jets over smooth and rough surfaces. J. Turbul., 15(3):186–207, 2014. http://dx.doi.org/10.1080/14685248.2014.888492 
  • U. Piomelli. Large eddy simulations in 2030 and beyond. Phil. Trans. R. Soc. A, 372(20130320):1–13, 2014. http://dx.doi.org/10.1098/rsta.2013.0320 
  • J. Yuan and U. Piomelli. Numerical simulations of sink-flow boundary layers over rough surfaces. Phys. Fluids, 26:015113–1–28, 2014. http://dx.doi.org/10.1063/1.4862672 

 



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