Absorption Spectroscopy System for Measurements of H2O, CO2 and CO Temperatures and Concentrations in Rotating-Detonation-Engines at 800 kHz Navy STTR FY2015.A Sol No.: Navy STTR FY2015.A Topic No.: N15A-T021 Topic Title: Absorption Spectroscopy System for Measurements of H2O, CO2 and CO Temperatures and Concentrations in Rotating-Detonation-Engines at 800 kHz Proposal No.: N15A-021-0081 Firm: Spectral Energies, LLC 5100 Springfield Street Suite 301 Dayton, Ohio 45431 Contact: Sukesh Roy Phone: (937) 902-6546 Abstract: The objective of the proposed Phase-I effort proposed by Spectral Energies LLC is to develop a versatile hyperspectral sensor system capable of performing >100 kHz in situ temperature and species concentration measurements of CO, CO2 and H2O in rotating detonation engines (RDEs) for gas temperatures up to 3000 K and gas pressures up to 50 bar. Development will include both the laser system as well as strategies for optical access into the RDE. The proposed laser system will consist of two main aspects. First, a broad scanning near-IR laser will used to measure high precision H2O temperatures at 100 kHz. In addition, another system consisting of several frequency-division-multiplexed fixed wavelength lasers will be used to determine CO, CO2 and H2O concentrations and temperatures at 800 kHz. Preliminary measurements using existing available hardware will be used to measure H2O, CO and CO2 concentrations and temperatures in an RDE facility located at the University of Cincinnati in Cincinnati, OH. Based on the Phase-I results, we propose to design, build and deliver a compact dedicated sensor system along with robust optical access tools for measuring temperature and species concentrations at speeds up to 800 kHz along multiple lines-of-sight during the Phase-II research effort. Benefits: The ability to noninvasively measure major combustion species such as CO, CO2, and H2O on a time-resolved basis at elevated temperatures and pressures is important for the characterization of the detonation process within the detonation channel of an RDE. Using such a system would enable the researcher to fully analyze the dynamic behavior of the structure of the both reacting flow fields and subsequent exhaust and thereby introduce the ability to empirically improve the control strategy of the RDE. Under the current program, a novel multispecies measurement system based on combination of tunable-laser absorption spectroscopy and frequency-division-multiplexed laser absorption spectroscopy will be developed, enabling an array of new marketable products and technologies for high-fidelity detonation measurements. Specifically, 1. Immediate benefits to the Navy: The implementation of an absorption spectroscopy-based measurement system into laboratory-scale detonation propulsive devices will greatly increase the available knowledge of the dynamic behavior of the reacting flow fields that occur during the detonation process. Such information is vital for the validation of the computational models that describe the operation of an RDE and for identification of any inherent weakness in current RDE strategies. Additionally, these tools will enable the optimization of RDE control strategies during the development process and can provide real time feedback on engine-health. 2. Scientific discovery - Understanding the fundamental behavior of the detonation process is a rich field of intellectually stimulating scientific challenges, which can quickly translate into technologies that provide societal benefits into propulsive technologies for spacecraft, hypersonic vehicles and military and civilian aircraft as well as for new power generation strategies. 3. Economic security and prosperity - The enormous roles that combustion of hydrocarbons plays in propulsive technologies cannot be overstated. The predicted thermodynamic advantages of the detonation cycle and the higher thrust-to-weight ratios over the traditional deflagration-based combustion strategies suggest that the development of RDEs can have a significate effect on US fuel consumption and vehicle development. Even slight efficiency improvement will have huge impacts on almost every corner of the US economy. The successful development of the commercial products will extend the global leadership of US on manufacturing and R&D in engines manufacturing. Return