Affiliation

Assad is an Associate Professor in the Department of Mechanical, Aerospace and Nuclear Engineering. He is also affiliated with the Scientific Computation Research Center and the Inverse Problems Center at RPI.

Background

Assad received his PhD. in Mechanical Engineering from Stanford University in 1998. His doctoral work involved developing accurate and efficient finite element methods for solving time-harmonic, wave propagation problems in unbounded domains. As a post-doctoral researcher at Stanford University he developed multiscale formulations of large eddy simulation for modeling turbulent flows and numerical methods for predicting noise generated by such flows. In 2001, Assad joined Boston University and in 2006 he moved to the Mechanical, Aerospace and Nuclear Engineering Department at RPI. Here, he continues to work on numerical methods for problems with multiple scales and inverse problems.

Research

Assad's research involves developing numerical methods for solving inverse problems and problems with multiple spatial and temporal scales. His work on multiscale problems includes modeling turbulent flows, problems with shocks and coupling molecular and continuum descriptions in fluids. In inverse problems he has been working on the promising new area of biomechanical imaging.

Teaching

Courses Taught at RPI :

  1. Engineering Dynamics, ENG 2090, Sophomore. Terms taught: Spring 2008 and Spring 2009
  2. Boundary Layers and Heat Transfer, MANE 4800, Senior. Term taught: Fall 2007
  3. Aeroelasticity and Structural Dynamics, MANE 4900, Senior. Term taught: Spring 2007
  4. Fluid Dynamics, MANE 6964, Graduate. Term taught: Fall 2006, Fall 2008 and Fall 2009
  5. Thermal and Fluids Engineering 1, ENG 2250, Sophomore. Terms taught: Spring 2006 and Spring 2009

Courses Taught at BU :

  1. Aerodynamics 1, AM420, Junior. Term taught: Spring 2004
  2. Elementary Mechanics, EK301, Sophomore. Terms taught: Fall 2001 & Spring 2003
  3. Continuum Mechanics, AM521, Graduate. Terms taught: Spring 2002 & Fall 2003
  4. Multiscale Methods in Mechanics, AM711, Graduate. Term taught: Spring 2005
  5. Introduction to Fluid Mechanics, EK303, Junior. Terms taught: Fall 2004 & Fall 2005
  6. Finite Element Analysis, AM707. Terms taught: Fall 2002 & Fall 2005

Honors

  • Humboldt Foundation award for experienced researchers, 2009.
  • ASME Special Achievement Award for Young Investigators in Applied Mechanics, 2007.
  • Institute of Physics Select Paper: Article in the IOP Select list. Selected by IOP editors for "their novelty, significance and potential impact on future research." Paper titled Elastic modulus imaging: some exact solutions of the compressible elastography inverse problem, by P.E. Barbone & A.A. Oberai, 2007.
  • Institute of Physics Select Paper: Article in the IOP Select list. Selected by IOP editors for "their novelty, significance and potential impact on future research." Paper titled Coupling between elastic strain and interstitial fluid flow: ramifications for poroelasticity imaging, by R. Leiderman, P.E. Barbone, A.A. Oberai & J.C. Bamber, 2006.
  • NSF Career Award: Fluid Dynamics and Hydraulics Division, Research award for work on large eddy simulation, January, 2005.
  • DOE Early Career PI Award in Applied Mathematics, Research award for work on multiscale problems, September, 2004.
  • DOD Breast Cancer Research Program: Concept Award, (with Paul Barbone, BU) Research award for work on detection and diagnosis of breast cancer, July, 2004.

    • Publications

    Peer Reviewed Journals :

    1. A comprehensive subgrid air entrainment model for RaNS modeling of bubbly flows near the free surface, J Ma, AA Oberai, DA Drew, RT Lahey Jr., and MC Hyman, submitted to the Journal of Fluid Mechanics.
    2. A mixed LES model based on the residual-based variational multiscale formulation, Z Wang and AA Oberai, submitted to Physics of Fluids.
    3. Adjoint-weighted variational formulation for the direct solution of inverse problems of general elasticity with full interior data, PE Barbone, CE Rivas, I Harari, U Albocher, AA Oberai and Y Zhang, to appear in the Interntional Journal for Numerical Methods in Engineering.
    4. Application of the variational Germano identity to the variational multiscale formulation, AA Oberai and D Sondak, submitted to Communications in Numerical Methods in Engineering.
    5. A quantitative subgrid air entrainment model for bubbly flows: plunging jets, J Ma, AA Oberai, DA Drew, RT Lahey Jr., and FJ Moraga, to appear in Computers and Fluids.
    6. Spectral analysis of the dissipation of the residual based variational multiscale method, Z Wang and AA Oberai, to appear in Computer Methods in Applied Mechanics and Engineering.
    7. Quantitative ultrasonic elastography for gel dosimetry, RA Crescenti, JC Bamber, AA Oberai, PE Barbone, JP Richter, C Rivas, NL Bush, and S Webb, to appear in Ultrasound in Medicine and Biology.
    8. Spectral analysis of the turbulent kinetic energy balance in a channel flow based on DNS data, IA Bolotnov, RT Lahey Jr., DA Drew, KE Jansen and AA Oberai, to appear in Computers and Fluids.
    9. Adjoint-weighted equation for inverse problems of incompressible plane-stress elasticity, U Albocher, AA Oberai, PE Barbone and I Harari, Computer Methods in Applied Mechanics and Engineering, volume 198 (30-32), 2412-2420, 2009.
    10. Sepctral cascade modeling of turbulent flow in a channel, IA Bolotnov, RT Lahey, DA Drew, KE Jansen and AA Oberai, Japanese Journal of Multiphase Flow, 23(2), 2009.
    11. Quantitative three-dimensional elasticity imaging from quasi-static deformation: a phantom study, MS Richards, PE Barbone and AA Oberai, Physics in Medicine and Biology, 54(3), 2009.
    12. Lanczos-iterated time reversal, AA Oberai, GR Feijoo and PE Barbone, Journal of the Acoustical Society of America -Express Letters, 2(125), 70-76, 2009.
    13. Linear and nonlinear elasticity imaging of tissue in-vivo: Demonstration of feasibility, AA Oberai, NH Gokhale, S Goenezen, PE Barbone, TJ Hall, AM Sommer and J Jiang, Physics in Medicine and Biology, 54, 1191-1207, 2009.
    14. In-Situ detection of impact damage in composites using carbon nanotube sensor netwroks, A Proper, W Zhang, S Bartolucci, AA Oberai and N Koratkar, Nanoscience and Nanotechnology Letters, vol 1(1), 3-7, 2009.
    15. Analytical estimates for the subgrid model for Burgers equation: Ramifications for spectral methods for conservation laws, AA Oberai, CE Colosqui and J Wanderer, International Jounral for Multiscale Computational Engineering, vol. 6, issue 4, 2008.
    16. A spectral turbulent cascade model for single and two-phase uniform shear flows, IA bolotnov, RT Lahey, Jr., DA Drew, KE Jansen and AA Oberai, Journal of Turbulence, vol. 9, N 26, 2008.
    17. A Two-Parameter Variational Multiscale Method for Large Eddy Simulation, J Wanderer and AA Oberai, Physics of Fluids (20) 085107, 2008.
    18. Optimal numerical solution of PDEs using the Variational Germano Identity. AA Oberai and Z Wang, Computer Methods in Applied Mechanics and Engineering, 197 (33-40), 2948-2962, 2008 .
    19. Solution of the nonlinear elsaticity imaging inverse problem: the compressible case. N.H. Gokhale, P.E. Barbone and A.A. Oberai, Inverse Problems, 24(4), 2008.
    20. Generalized Smagorinsky Model in Physical Space. C.E. Colosqui & A.A. Oberai, Computers and Fluids, 37(3), 207-217, 2008.
    21. The adjoint weighted equation for steady advection in a compressible fluid. A.A. Oberai, P.E. Barbone & I. Harari, International Journal for Numerical Methods in Fluids, 54(6-8), 683-693, 2007.
    22. Elastic modulus imaging: some exact solutions of the compressible elastography inverse problem. P.E. Barbone & A.A. Oberai, Physics in Medicine and Biology, 52(6), 1577-1593, 2007.
    23. Adjoint-weighted variational formulation for direct solution of inverse heat conduction problem. PE Barbone, AA Oberai and I Harari, Inverse Problems, 23, 2325-2342, 2007.
    24. Coupling between elastic strain and interstitial fluid flow: ramifications for poroelasticity imaging. R. Leiderman, P.E. Barbone, A.A. Oberai & J.C. Bamber, Physics in Medicine and Biology, 51(24), 6291-6313, 2006.
    25. A Dynamic Multiscale Viscosity Method for the Spectral Approximation of Conservation Laws. A.A. Oberai & J. Wanderer, Computer Methods in Applied Mechanics and Engineering, 195(13-16), 1778-1792, 2006.
    26. Acoustic eigenvalues of rectangular rooms with arbitrary wall impedances using the interval Newton/generalized bisection method. Y. Naka, A.A. Oberai & B. Shinn-Cunningham, Journal of Acoustical Society of America, 118(6), 3662-3671, 2005.
    27. Variational Formulation of the Germano Identity for the Navier-Stokes Equations. A.A. Oberai & J. Wanderer, Journal of Turbulence, vol. 6, 2005.
    28. A Dynamic Approach for Evaluating Parameters in a Numerical Method. A.A. Oberai & J. Wanderer, International Journal for Numerical Methods in Engineering, 62:50-71, 2005.
    29. Evaluation of the Adjoint Equation Based Algorithm for Elasticity Imaging. A.A. Oberai, N.H. Gokhale, M.M. Doyley, J.C.Bamber, Physics in Medicine and Biology, 49:2955-2974, 2004.
    30. Sensitivity of the Scale Partition for Variational Multiscale LES of Channel Flow. J. Holmen, T.J.R. Hughes, A.A. Oberai and G.N. Wells, Physics of Fluids, 16(3):824-827, 2004.
    31. An Application of Shape Optimization in the Solution of Inverse Acoustic Scattering Problems. G.R. Feijoo, A.A. Oberai and P.M. Pinsky, Inverse Problems,20:199-228, 2004.
    32. A Krylov subspace projection method for simultaneous solution of Helmholtz problems at multiple frequencies. M.M. Wagner, P.M.Pinsky, A.A. Oberai and M. Malhotra, Computer Methods in Applied Mechanics and Engineering, 192 (41-42): 4609-4640 2003.
    33. Solution of Inverse Problems in Elasticity Imaging Using the Adjoint Method. A.A. Oberai, N.H. Gokhale and G.R. Feijoo, Inverse Problems, 19 (2003) 297-313.
    34. Calculation of Shear Stresses in Fourier-Galerkin Formulation of Turbulent Channel Flows: Projection, the Dirichlet Filter and Conservation. T.J.R. Hughes and A.A. Oberai, Journal of Computational Physics 188(1):281--295, 2003.
    35. Trailing-edge noise from a finite chord airfoil. A.A. Oberai, F. Roknaldin and T.J.R. Hughes, AIAA journal, Volume 40, No. 11, 2206-2216 (2002).
    36. Shape sensitivity calculations for exterior acoustics problems. G.R. Feijoo, M. Malhotra, A.A. Oberai, and P.M. Pinsky, Engineering Computations, 18(3/4):376--391.
    37. Large Eddy Simulation of Turbulent Channel Flows by the Variational Multiscale Method. T.J.R. Hughes, A.A. Oberai and L. Mazzei, Physics of Fluids 13(6):1784--99, 2001.
    38. The Multiscale Formulation of Large Eddy Simulation: Decay of Homogeneous Isotropic Turbulence. T.J.R. Hughes, L. Mazzei, A.A. Oberai and A.A. Wray, Physics of Fluids, 13(2):505--512, 2001.
    39. Shape sensitivity analysis applied to exterior acoustics. G.R. FeijoŽo, A.A. Oberai and P.M. Pinsky. American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA 28 (28), pp. 271-278, 2001.
    40. Computational Procedures for Determining Structural Acoustic Response due to Hydrodynamic Sources. A.A. Oberai, F. Roknaldin and T.J.R. Hughes, Computer Methods in Applied Mechanics and Engineering, 190(3-4):345--361, 2000.
    41. A Numerical Comparison of Finite Element Methods for the Helmholtz Equation. A.A. Oberai and P.M. Pinsky, Journal of Computational Acoustics, 8(1):211--221, 2000.
    42. A Residual-based Finite Element Method for the Helmholtz equation. A.A. Oberai and P.M. Pinsky, International Journal for Numerical Methods in Engineering, 49:399-419, 2000.
    43. On the Implementation of the Dirichlet-to-Neumann Map for Iterative Solution of the Helmholtz Equation. A.A. Oberai, M. Malhotra and P.M. Pinsky, Journal of Applied Numerical Mathematics, 27(4):443--464, 1998.
    44. A Multiscale Finite Element Method for the Helmholtz Equation. A.A. Oberai and P. M. Pinsky, Computer Methods in Applied Mechanics and Engineering, 154:281--297, 1998.

    Chapters in Books :

    1. The Variational Multiscale Formulation of LES with Application to Turbulent Channel Flows, TJR Hughes and AA Oberai, in Geometry, Mechanics and Dynamics, Volume in Honor of the 60th Birthday of JE Marsden.

    Conference Proceedings :

    1. Transfer of energy in the variational multiscale formulation of LES. A.A. Oberai, V. Gravemeier and G.C. Burton, Proceedings of the Center of Turbulence Research Summer Program, Stanford University Stanford, CA, 2004.
    2. Simultaneous Elastic Image Registration and Elastic Modulus Reconstruction. N. Gokhale, M. Richards, A. Oberai, P. Barbone, M. Doyley, Proceedings of the IEEE International Symposium on Biomedical Imaging, April 15-18, 2004, Arlington, VA, USA.
    3. The finite element method with the Dirichlet-to-Neumann map for sound-hard rectangular rooms. Y. Naka, A.A.Oberai, and B.G.Shinn-Cunningham, Proceedings of the International Congress on Acoustics, Kyoto, Japan, 4-9 April 2004.
    4. The Variational Multiscale Formulation of LES: Channel Flow at Re_\tau=590. A.A. Oberai and T.J.R. Hughes, 40th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 2002.
    5. Shape Sensitivity Analysis Applied to Exterior Acoustics. G. R. Feijoo, A.A. Oberai and P. M. Pinsky, Proceedings of IMECE 2001, 2001 ASME International Mechanical Engineering Congress and Exposition, New York, NY, USA.
    6. Computation of trailing edge noise from an incompressible flow calculation. A.A. Oberai and M. Wang, Proceedings of the Center of Turbulence Research Summer Program, Stanford University Stanford, CA, 2000.
    7. Implementing Highly Accurate Non-reflecting Boundary Conditions for Large-scale Problems in Structural Acoustics. A.A. Oberai, M. Malhotra and P.M. Pinsky, Proceedings of IUTAM Symposium on Computational Methods for Unbounded Domains, Boulder, CO, 1997.

    Group

  • Zhen Wang (PhD student).
  • Sevan Goenezen (PhD student).
  • Yixiao Zhang (PhD student).
  • Jianfeng Liu (PhD student).
  • Jayanth Jagalur Mohan (PhD student).
  • David Sondak (PhD student).
  • Dr. Jingsen Ma (Post-doctoral researcher).
  • Dr. Jean-Francois Dord (Post-doctoral researcher).
  • Dr. Elizabete Rodrigues-Ferreira (Post-doctoral researcher).

    • Openings

    There are openings in my research group in computational fluid mechanics (Large Eddy Simulation), numerical methods for multiscale problems and biomechanical imaging for both doctoral candidates and post-doctoral researchers. Interested individuals should contact me.