Development of test facility and optical instrumentation for turbulent combustion research

Abstract

Practical combustion systems as complex as a gas turbine combustor, a ramjet, or an afterburner pose many design and modeling difficulties. This has created an urgent need for well conceived turbulent combustion experiments to validate the models and to improve their potential design capabilities. With that broad goal in mind, the U.S. Air Force Wright Aeronautical Laboratories, Aero Propulsion Laboratory initiated a major program with the University of Dayton Research Institute to 1) develop a sophisticated combustion test facility, 2) develop state-of-the-art optical instrumentation capable of measurements in nonreactiye and reactive turbulent flows, and 3) carry out well conceived turbulent combustion experiments. This paper describes the development of the combustion test facility and the optical instrumentation. A turbulent flame burner provides low exit turbulence (<0.25%), predictable velocity profile; and it is capable of producing a variety of flame configurations. A two-component LDA system, capable of measuring velocity fluctuations over three orders of magnitude, has been designed. A three-channel laser Raman/Rayleigh spectroscopy (LRS) system, which can simultaneously measure temperature, density, and species concentration, has been constructed. Integration pf the LDA-LRS systems is carried out to measure complex correlations between velocity, temperature, concentration, and density in a turbulent flame. Design and development of auxiliary systems and equipment such as fuel and airflow networks, LDA seeders, and the flow visualization system are described in detail.