A numerical study of detonation diffraction
An investigation of detonation diffraction through an abrupt area change has been carried out via a set of two-dimensional numerical simulations parameterized by the activation energy of the reactant. Our analysis is specialized to a reactive mixture with a perfect gas equation of state and a single-step reaction in the Arrhenius form. Lagrangian particles are injected into the flow as a diagnostic tool for identifying the dominant terms in the equation that describes the temperature rate of change of a fluid element, expressed in the shock-based reference system. When simplified, this equation provides insight into the competition between the energy release rate and the expansion rate behind the diffracting front. The mechanism of spontaneous generation of transverse waves along the diffracting front is carefully analysed and related to the sensitivity of the reaction rate to temperature. We study in detail three highly resolved cases of detonation diffraction that illustrate different types of behaviour, super-, sub- and near-critical diffraction.
"Reprinted with the permission of Cambridge University Press." (Received 10 March 2003 and in revised form 15 October 2003). This work was carried out at the Caltech ASC 'Centre for Simulation of Dynamic Response of Materials' and funded by Contract B341492 under DOE Contract W-7405-ENG-48.
Published - ARIjfm05.pdf