Universal Mechanism of Turbulence-Induced Deflagration-to-Detonation Transition from Terrestrial Chemical Systems to Supernovas

点击翻译按钮获取中文摘要

Efforts to predict and control the onset of detonation waves, i.e. combustion driven shock waves, have been a serious challenge for research community and is important for a wide range of applications where detonations can be beneficial or harmful. In confined spaces, detonations can naturally develop from low-speed deflagration or laminar flames through interactions with compressible or shock waves. However, in unconfined spaces the mechanism of transition from a low speed deflagration wave to a detonation wave remains unclear. Findings from this research can apply to development of new power generation and propulsion systems, e.g., gas turbine engines and Rotating Detonation Engines (RDEs), and industrial safety of mining operations, fuel-storage, chemical processing, and nuclear power-generation facilities, as well as unbounded astrophysical systems such as supernova explosions. Additionally, this work will have a broader impact by preparing next generation of scientists and engineers to be leaders in turbulent reacting flows. Students involved in the research and education will understand the role of turbulence in improving the efficiency of combustion-based systems. The overarching goal is to drive student growth in STEM disciplines through outreach, learning, and professional education. This research explores a novel mechanism through which fast turbulent flames can become intrinsically unstable and spontaneously transition to a detonation even in completely unconfined environments. The goal of this project is to develop a comprehensive understanding of the spontaneous runaway mechanism of turbulent flames, and Turbulence-induced Deflagration-to-Detonation Transition (TDDT). The runaway mechanism of compressible turbulent flames will be experimentally explored in a unique “Turbulent Shock Tube” (TST) facility. Advanced ultra-fast laser diagnostic techniques are used for the investigation. The research entails several novel studies of high-speed compressible turbulent flames and combustion that is fundamental to many modern energy and propulsion systems, such as gas-turbine/internal-combustion engines to scramjets and rotating detonation engines (RDEs), to exploding stars.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.