研究用冲压发动机燃烧器中进行燃料和空气混合过程的粒子成像和气体采样测量研究

An ongoing research ramjet program initiated at ONERA under support of DGA (French ministry of Defence) aims to improve methodology for ramjet combustion chamber design and tuning by using validated CFD codes. A transparent model rig was used for aerodynamic tests with air flows at atmospheric pressure and room temperature. In the case of the simulation of a Solid Ducted Rocket (SDR) combustor, two fuel holes were located at the head end of the combustor in order to simulate the fuel supply from the auxiliary gas generator in the case of a real combustor. Among the various mechanisms that are controlling the development of the combustion processes inside the combustor, the mixing is certainly one of the most crucial as far as stability or efficiency are concerned. The work presented in this paper is addressing the characterization, in absence of combustion, of the turbulent flow velocity and scalar fields associated to the mixing between fuel (simulated by CO2) and air. Particle image velocimetry (PIV) and gas sampling analysis are the two techniques that were used to serve that purpose. Results presented in this paper are very useful to assess the ability of numerical computations, based either on Reynolds-Averaged Navier-Stokes (RANS) or Large-Eddy Simulations (LES) approaches, to reliably predict velocity and fuel concentration fields inside this research combustor.