Special Seminar: Acoustic Timescale Characterization of Hot Spot Auto-Ignition
- Wednesday, March 18, 2015 at 11:00am
- Roberts Hall, Room 218 - view map
Special Seminar: Acoustic timescale characterization of hot spot auto-ignition
Jonathan Regele, Assistant Professor, Iowa State University
11am Wednesday 3/18 in Roberts 218
Engine knock is a common problem in internal combustion engines and other combustion applications. These events are caused by localized hot spots that auto-ignite outside the main spark ignited region. Much of the existing literature models hot spots with linear temperature gradients. However, hot spots usually have a local maximum of some finite size at the center. In this presentation, we explore the effect of modeling a hot spot as a linear temperature gradient adjacent to a finite sized high temperature plateau. Numerical simulations of hot spot ignition are performed in one and two dimensions. Acoustic timescale analysis is used to characterize the expected reaction behavior in a simple manner. It is shown that the ratio of the reaction time to acoustic time of the hot spot determines whether the hot spot reacts at constant pressure, constant volume to produce strong shock waves, or somewhere in between to create compression waves.
Dr. Regele is currently an Assistant Professor at Iowa State University in the Department of Aerospace Engineering. Prior to his current position, he obtained a Master’s in Physics in 2003 and a Ph.D. in Mechanical Engineering from the University of Colorado. He worked for a small startup company in the power generation and energy sector prior to his position as a Postdoctoral Scholar at the California Institute of Technology. Dr. Regele is a member of APS, the Combustion Institute, AIAA, and ASME. His current research focuses on compressible reactive and multiphase flows.