A Spectroscopic Investigation on the Fundamental Reaction Mechanisms in the Oxidation of Metal-Doped exo-Tetrahydrodicyclopentadiene (JP-10)
Abstract
mechanisms, and kinetics involved in the oxidation of Jet Propellant-10 (JP-10; exo-tetrahydrodicyclopentadiene) jet fuel doped wit nanopowders (RMNP; Ti-Al, Ti-B, Ti-Al-B). There is currently an incomplete understanding of the elementary steps involved in the oxi dation of metal-doped hydrocarbon-based JP-10 fuel in the liquid and in the gas phase. This requires novel spectroscopic diagnostics herein proposed; no comprehensive study has been conducted yet, in which the oxidation mechanisms of JP-10 along with the overall s pectrum of newly formed open and closed shell molecules have been explored on line and in situ. Our findings challenge traditional b oundaries of theory and experimentation revealing novel insights and energy concepts beyond conventional chemistry. An understanding of these processes relies on fundamental advances in experimental liquid and gas phase physical chemistry along with innovative dia gnostics, novel metal additives, and electronic structure calculations as combined here ultimately affording original concepts for t he development of high-energy-density fuels for air breathing propulsion systems. Methodology & Techniques: The oxidation of JP-10 i n the presence of metal-based energetic additives involves the injection of the fuel into a jet engine accompanied by the formation of droplets, the liquid-vapor equilibrium of the droplets, and the oxidation of the fuel. Hence an understanding of the oxidation o f fuel droplets, which are doped with metal additives, and of the gas phase molecules interacting with energetic metal additives is needed. This requires two complementary techniques. First, as an emerging technique, an ultrasonic levitation device explores the o xidation of metal-doped levitated droplets under container-less conditions (liquid phase); it incorporates complementary in situ dia gnostics (infrared (IR), Raman (Ra), ultravioletvisible (UV-Vis) spectroscopy, VIS and IR imaging) to afford the complex oxidation mechanisms of metal-doped JP-10 droplets. This is achieved by tracing the temporal evolution (kinetics) of the reactants and (funct ional groups of) products, which are formed in the oxidation processes, spectroscopically. Second, a high temperature chemical micro reactor reveals the oxidation mechanisms of JP-10 over metal-based additives in the gas phase. This is achieved through an in situ i dentification of the products in a supersonic molecular beam exploiting vacuum ultraviolet photoionization (VUVPI) followed by a mas s spectroscopic analysis of the ions in a reflectron time-of-flight mass spe ith a computational investigation of the oxidation processes. This approach provides a first isomer specific, comprehensive inventor y of all open and closed shell products along with their branching ratios. Outcome & Significance: Besides the fundamental scientifi c interest from the physical chemistry community to unravel the elementary mechanisms of the oxidation of JP-10 in the liquid and ga s phase in the presence of energetic materials, our studies have unprecedented impact to provide basic insights into the (catalytic) decomposition and oxidation mechanisms of complex organic molecules, to reveal unusual isomerization processes of transient species , to deliver insights into chemical bonding of carbon-, hydrogen-, oxygen-, and metal-bearing radicals formed in these processes, an d to provide minimum ignition energies of the doped fuel along with diagnostics of the radiation emitted during the combustion. This fundamental research can be applied to develop extended range air-breathing chemical propulsion systems required in volume limited ordnance systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 16, 2021
- Source ID
- N000142212010
Entities
People
- Ralf I Kaiser
Organizations
- Office of Naval Research
- United States Navy
- University of Hawaiʻi System