Response Enhancement for PITLIF Instrument

Abstract

Previous work for AFOSR has demonstrated the feasibility of picosecond time-resolved laser-induced fluorescence (PITLIF) for real-time, quenching-corrected measurements of minor species concentrations in laminar and turbulent flames. Specifically, time-series measurements of CH and OH fluorescence have been demonstrated for the first time via PITLIF. These measurements can provide power spectral densities (PDFs) as well as the more traditional probability density functions (PDFs). However, the quenching rate coefficient must simultaneously be measured to quantify the fluorescence time series, and this was not previously accomplished. In this report, a new photon-counting procedure is presented that possesses the data processing rate required for quantitative concentration measurements on a time scale shorter than that characteristic of turbulence. This technique was first applied to laminar flames, and a correction procedure which accounts for the nonlinear response of the photon-counting system was derived for extension of the technique to turbulent flames. The fully developed PITLIF instrument was then applied to the first known measurements of quantitative OH time series in turbulent reacting jets.

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Document Details

Document Type
Technical Report
Publication Date
Jan 21, 2000
Accession Number
ADA373455

Entities

People

  • Galen B. King
  • Normand M. Laurendeau

Organizations

  • Purdue University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Chemical Reactions
  • Fluid Dynamics
  • Fluid Mechanics
  • Fluids
  • Fluorescence
  • Information Science
  • Laser Induced Fluorescence
  • Measurement
  • Mechanics
  • Physics
  • Picosecond Time
  • Quantum Yields
  • Repetition Rate
  • Reynolds Number
  • Statistics
  • Turbulence

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Statistical inference.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers