Grant: Discovery Grants Program - Individual

Under favorable conditions, a detonative combustion can occur in a reactive system causing a significant increase in temperature and pressure of the surrounding medium. A detonation is a supersonic, self-sustained, combustion-driven wave, and an intriguing dynamical event observed in nature. The destructive nature of this phenomenon implies a good knowledge of detonation dynamics is required for the safe management of many industrial settings. A proper, controlled detonative combustion can also provide innovative applications particularly for aerospace systems and miniature mechanical devices which require a powerful driving source. A five year research program is proposed to advance the understanding of detonation dynamics and its potential technological applications. This will be accomplished through modeling of fundamental detonation problems of direct initiation and limit phenomena in a hierarchical approach, from basic physically-based analytical modeling to high-fidelity, unsteady simulations. An integrated model with multiple mechanisms of losses, boundary layer effects and flow instabilities for the velocity deficits and limits will be developed. Unsteady simulations will be used to study the dynamics of near-limit detonations; to numerically determine the initiation energy; and analyze the cellular evolution of diverging detonations. Real gas effects and complex chemistry including different equations of state and non-equilibrium effects will be assessed to improve the current model description of detonations. In addition to the measurement of explosion hazards for blended alternative fuel mixtures and dispersed reactive media, experiments will be conducted to explore how a detonation is affected by sudden changes in chemical and thermodynamic states of the reacting flow, revealing underlying dynamical processes within its structure. Finally, two distinct applications of the detonation phenomenon will be explored. The first application deals with the oblique detonation wave (ODW) concept for supersonic propulsion systems. The aim is to understand the ODW formation structure and instability through realistic flow simulations for developing workable ODW engines. The second topic is on the development of a combustion-type, controlled release, needle-free, liquid jet injection technology for drug delivery. The idea is to design a needle-free injector that will harness the pressure generation from different modes of combustion process. The ultimate goal of this research is to advance the fundamental understanding of how a detonation is formed, the effects influencing its propagation, and implementing its use in a controlled manner for engineering applications. This research program will have a broad impact in energy, defense, aerospace and biomedical industries and produce a group of HQPs with expertise in explosion safety and detonation physics.