Analysis On Two-phase Flow Field Of Civil Aviation Engine Combustor

In this paper, in view of the structure characteristics of a reverse-flow combustor of small engine, research about its interior three-dimensional two-phase flow flied. First,according to the practical measurement data, UG software was used to build three dimensional model of combustor, in order to optimize the flow field and improve burning performance, design a single swirl that meets this combustor. Then, hexahedral structure grid was adopted to generate the combustion interior flow field, tetrahedral unstructured grid was adopted to generate the swirl channel flow field. Final, the file was imported Fluent to make the simulation calculation, with Realizable k-? turbulent model, P1 radiation model,non-premixed PDF combustion model and TBA particular break-up model, to study the reverse flow combustor cold flow field and hot flow field, burning performance and combustion characteristics.The study results show that, because of the flow viscosity and strong swirling flow effects, it forms a negative pressure zone downstream the swirl exit, this causes the flow reflux and recirculation zone. Due to the primary holes truncation affection, the zone had a axial length of 28 mm, and the mixer holes are positive to the cooling. The example of this paper has a 180 degree big bend structure, which leads to the out velocity increases. Through the comparison of the effects of different turbulence models on the simulation results, RKE model is the most suitable for strong swirl combustor numerical simulation.Hot flow study results show that, the flammable length was cutting off by primary holes;some resting fuel burns at mixing holes, at the downstream of mixing holes, the temperature is a little colder, but the temperature distribution of combustor outlet is not even, this is because the simplification of combustor structure is unreasonable, primary holes and mixing holes should be staggered arrangement, this causes bad cooling effects.