Measurements of NO and OH Concentrations in Vitiated Air Using Diode Laser-Based Ultraviolet Absorption Sensors (Postprint)

Abstract

Diode-laser-based sensors were implemented to measure the concentrations of nitric oxide (NO) and hydroxyl (OH) radicals in the vitiated inlet airflow of a model scramjet combustor. The sensors utilized sum-frequency-mixed sources consisting of a fixed frequency 532-nm laser and a tunable diode laser to generate ultraviolet radiation for absorption spectroscopy with electronic transitions of OH and NO. Sensitive, interference-free, absolute measurements were possible, enabling the first measurements of both species in a model scramjet combustor using diode-laser-based sensors. With wavelength-modulation spectroscopy, no absorption by OH was evident in the vitiated airflow, verifying that the OH concentration was below the 0.2-ppm detection limit of the sensor.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2006
Accession Number
ADA478683

Entities

People

  • Campbell D. Carter
  • James. R. Gord
  • Keith D. Grinstead Jr.
  • Mark Gruber
  • Robert P. Lucht
  • Tarun Mathur
  • Terrence R Meyer
  • Thomas N. Anderson

Organizations

  • Purdue University

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Combustors
  • Detection
  • Detectors
  • Distributed Feedback Lasers
  • Frequency
  • Laser Diodes
  • Lasers
  • Measurement
  • Mechanical Engineering
  • Optical Materials
  • Radiation
  • Spectra
  • Spectroscopy
  • Supersonic Combustion
  • Supersonic Combustion Ramjet Engines

Fields of Study

  • Physics

Readers

  • Internal Combustion Engine (ICE) Technology.
  • Optical Physics and Photonics.
  • Spectroscopy.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Microelectronics
  • Microelectronics - Microelectromechanical Systems