ONERA test Facilities for Combustion in Aero Gas Turbine Engines, and Associated Optical Diagnostics

The aim of this paper is to provide an overview of the ONERA test facilities devoted to the study of combustion in gas turbine engines. The objectives of the experimental studies performed with these test rigs are very ambitious and extend from building databases for the validation of codes and models used in numerical simulation to applied research for evaluating the performance of advanced aero injection systems in mono-sector, multi-sector or full annular combustion chambers. For more than ten years, aside from standard measurements (i.e., pressure, temperature, mass flow rates, gas analysis sampling), optical diagnostics have been widely associated with the test campaigns carried out in these rigs. Many optical methods are now very commonly used to measure for instance flow velocity fields, size and velocity of droplets, and the location of combustion zones. Other methods that are more difficult to implement, or still under development, are being increasingly used or proposed for measuring physical or chemical parameters, such as temperature, size of soot particles or concentration of combustion products. Examples of the results obtained with the ONERA test facilities and optical diagnostics are given, in order to illustrate the studies presented in this paper.