Christopher Ivey

  • Academic Institution: Stanford University
  • Program Year: 3
  • Practicum(s):
    Argonne National Laboratory (2012)
  • Degree(s):
    M.B.S. Mechanical Engineering, Johns Hopkins University, 9/2010
  • Field of Study: Computational Fluid Dynamics
  • Academic Advisor: Parviz Moin

Summary of Research:

The burning of oil, although unfavorable from a conservational and environmental standpoint, is paramount to our economy for the widespread use of liquid combustion engines in our transportation system. Sadly, the physics of these systems still are poorly understood due to the enriched nature of multiphase flows, i.e., the mutual interaction of many subsystems causing simultaneous phenomena spanning a wide range of spatial and temporal scales. Of particular importance to the control and efficacy of liquid combustion engines is jet atomization, the breakup and evaporation of the liquid jet into a combustible fuel vapor-air mixture. I am developing a multiphase platform that can detail the jet atomization process in a full-scale liquid combustion simulation.

The ever-changing topology and cascade of length scales involved in jet atomization preclude the use of explicit surface representations and point-particle methods during the entire breakdown process, so I am building on implicit interface tracking schemes that respect the complexity of the system. I leverage the volume of fluid (VOF) method, a volume fraction tracking phase description, extended by a piecewise-linear interface calculation (PLIC) representation, where the interface is locally approximated by a plane. VOF-PLIC naturally accommodates breakup and coalescence of surfaces due to its implicit interface representation, and its geometric nature permits the construction of conservative advection operators. VOF-PLIC relies on an incompressible flow description, so a variable-density pressure projection is required. Realistic combustions are characterized by large density ratios, creating numerical stability issues for the mass and momentum advection and the pressure projection steps. Further, the combustion chambers contain multiple inlets of an intricate design, necessitating the use of an unstructured mesh. I am building a framework to simulate jet atomization, and that entails the following developments in VOF-PLIC for unstructured domains: an advection scheme that conservatively and consistently advects mass and momentum, an accurate interface reconstruction method for estimations of surface normals and curvatures, a fast and stable variable-density pressure projection, and a ligament-droplet breakup model for coupling with point-particle methods for evaporation into fuel vapor.

Publications:

(1) C. B. Ivey, P. Moin, “Conservative volume of fluid advection method on unstructured grids,” Center for Turbulence Research, Annual Research Briefs, 2012.
(2) B. F. Bathel, P. M. Danehy, S. B. Jones, C. B. Ivey, “Multiple Velocity Profile Measurements in Hypersonic Flows Using Sequentially-Imaged Fluorescence Tagging,” AIAA Journal, Vol. 49, No. 9., pp. 1883-1896, 2011.
(3) N. Jiang, M. Webster, W. R. Lempert, J. D. Miller, T. R. Meyer, C. B. Ivey, P. M. Danehy, “MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel”, Applied Optics Vol. 50, Iss. 4, pp. A20-A28, 2011.
(4) C. B. Ivey, P. M. Danehy, A. R. Mazaheri, B. F. Bathel, A. A. Dyakonov, J. A. Inman, S. B. Jones, “Comparison of PLIF and CFD Results for the Orion CEV RCS Jets,” AIAA-2011-0713, 49th AIAA Aerospace Sciences Meeting, Orlando, FL, January 2011.
(5) B. F. Bathel, P. M. Danehy, J. A. Inman, A. N. Watkins, S. B. Jones, W. E. Lipford, K. Z. Goodman, C. B. Ivey, C. P. Goyne, “Hypersonic Laminar Boundary Layer Velocimetry with Discrete Roughness on a Flat Plate”, AIAA-2010-4998, 40th Fluid Dynamics Conference and Exhibit, Chicago, IL, June 2010.
(6) P. M. Danehy, C. Ivey, J. A. Inman, B. Bathel, S. B. Jones, N. Jiang, M. Webster, W. Lempert, J. Miller, T. Meyer, “High-speed PLIF imaging of hypersonic transition over discrete cylindrical roughness”, AIAA-2010-703, 48th AIAA Aerospace Sciences Meeting, Orlando, FL, January 2010.
(7) P. M. Danehy, C. Ivey, B. F. Bathel, J. A. Inman, S. B. Jones, A. N. Watkins, K. Goodman, B. D. Leighty and W. K. Lipford, N. Jiang, M. Webster, W. Lempert, J. Miller, T. Meyer, “Orbiter BLT flight experiment wind tunnel simulations: nearfield flowfield imaging and surface thermography”, AIAA-2010-1571, 48th AIAA Aerospace Sciences Meeting, Orlando, FL, January 2010.
(8) B. F. Bathel, P. M. Danehy, J. A. Inman, S. B. Jones, C. B. Ivey, and C. P. Goyne, “Multiple Velocity Profile Measurements in Hypersonic Flows Using Sequentially-Imaged Fluorescence Tagging”, AIAA-2010-1404, 48th AIAA Aerospace Sciences Meeting, Orlando, FL, January 2010.
(9) P. M. Danehy, B. Bathel, C. Ivey, J. A. Inman, S. B. Jones, “NO PLIF study of hypersonic transition over a discrete hemispherical roughness element”, AIAA-2009-0394, 47th AIAA Aerospace Sciences Meeting, Orlando, FL, January, 2009.

Awards:

1) DOE Computational Science Graduate Fellowship
2) Stanford University Graduate Fellowship
3) Johns Hopkins University Mechanical Engineering Charles A. Miller Award
4) Undergraduate NASA Aeronautics Scholarship Program Fellowship
5) Johns Hopkins University Mechanical Engineering Robert Gerstmyer Award
6) Superior Accomplishment Award from NASA LaRC
7) Accepted into Tau Beta Pi Engineering Honor Society
8) Accepted into Pi Tau Sigma Mechanical Engineering Honor Society
9) Johns Hopkins University Endowed Scholarships (x3)