Department Seminar of Naor Zadok - Optimization of Flow and Reaction Models for Capturing Gas-Phase Cellular Detonation Properties in Premixed Mixtures
SCHOOL OF MECHANICAL ENGINEERING SEMINAR
Wednesday, June 1, 2022 at 14:30
Wolfson Building of Mechanical Engineering, Room 206
Optimization of Flow and Reaction Models for Capturing Gas-Phase Cellular Detonation Properties in Premixed Mixtures
M.Sc. student of Dr. Yoram Kozak
Detonation is a type of combustion wave involving a supersonic exothermic front that drives a shock wave. This process creates very high pressure and temperature gradients, and releases vast amounts of energy in short time periods. In particular, gas-phase detonations in premixed fuel and oxidizer mixtures are characterized by unsteady and unstable behavior, which can involve complex cellular structures.
It is today well-established that detonation properties for a given gaseous mixture, such as the detonation wave speed and the typical cellular patterns, are vital for various engineering applications. For instance, development of highly efficient detonation-based engines and improved safety measures for fuel storage facilities.
The ability to predict the behavior of gas-phase detonation waves via numerical simulations can assist the development of the above-mentioned applications. However, typical detonation simulations are multidimensional and involve complex chemistry reaction mechanisms. This leads to extremely high computational costs per simulation, and significantly limits the number of possible simulations. Simplified single-step reaction models allow performing these simulations with a considerably lower computation cost, and therefore more simulations can be conducted in a given time.
In the present study, we will develop a new numerical framework that can efficiently calibrate flow and simplified single-step reaction models to mimic detonation properties derived by detailed chemical mechanisms. This framework is based on an evolutionary algorithm coupled with a set of non-linear algebraic equations for detonation properties. We will also present a new model that can predict the detonation cell length and width for single-step reaction multidimensional detonation simulations. This model will allow us tuning and optimizing the flow and reaction rate parameters based on experimental detonation cell size data for any given premixed mixture.
In the future, we intend to utilize the proposed framework for conducting multidimensional reactive flow simulations of different novel energy conversion and propulsion systems.