A Caltech Library Service

Mixing, Chemical Reactions, and Combustion in Supersonic Flows


Cymbalist, Niccolo (2016) Mixing, Chemical Reactions, and Combustion in Supersonic Flows. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9G73BNR.


Experiments were conducted at the GALCIT supersonic shear-layer facility to investigate aspects of reacting transverse jets in supersonic crossflow using chemiluminescence and schlieren image-correlation velocimetry. In particular, experiments were designed to examine mixing-delay length dependencies on jet-fluid molar mass, jet diameter, and jet inclination.

The experimental results show that mixing-delay length depends on jet Reynolds number, when appropriately normalized, up to a jet Reynolds number of 500,000. Jet inclination increases the mixing-delay length, but causes less disturbance to the crossflow when compared to normal jet injection. This can be explained, in part, in terms of a control-volume analysis that relates jet inclination to flow conditions downstream of injection.

In the second part of this thesis, a combustion-modeling framework is proposed and developed that is tailored to large-eddy simulations of turbulent combustion in high-speed flows. Scaling arguments place supersonic hydrocarbon combustion in a regime of autoignition-dominated distributed reaction zones (DRZ). The proposed evolution-variable manifold (EVM) framework incorporates an ignition-delay data-driven induction model with a post-ignition manifold that uses a Lagrangian convected 'balloon' reactor model for chemistry tabulation. A large-eddy simulation incorporating the EVM framework captures several important reacting-flow features of a transverse hydrogen jet in heated-air crossflow experiment.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemically reacting flow; jet-in-crossflow; mixing; supersonic combustion; large-eddy simulation; tabulated chemistry
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Aeronautics
Awards:Ernest E. Sechler Memorial Award in Aeronautics, 2015. Hans G. Hornung Prize, 2016.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Dimotakis, Paul E.
Thesis Committee:
  • Shepherd, Joseph E. (chair)
  • Blanquart, Guillaume
  • Austin, Joanna M.
  • McKeon, Beverley J.
  • Dimotakis, Paul E.
Defense Date:6 May 2016
Non-Caltech Author Email:niccolo.cymbalist (AT)
Funding AgencyGrant Number
Air Force Office of Scientific ResearchFA9550-10-1-0262
Air Force Office of Scientific ResearchFA9550-12-1-0461
NSF Major Research Instrumentation (MRI)EIA-0079871
Defense University Research Instrumentation Program (DURIP) AFOSRFA9550-10-1-0553
Record Number:CaltechTHESIS:05242016-143905617
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9742
Deposited By: Niccolo Cymbalist
Deposited On:26 May 2016 20:44
Last Modified:07 Nov 2022 23:14

Thesis Files

PDF - Final Version
See Usage Policy.


Repository Staff Only: item control page