Research On Parametric Numerical Simulation Of A Small Aeroengine Combustor

With the development of computer, the design of aeroengine increasingly relies on the numerical simulation.But the evolution of geometry modeling, meshing and the calculation models has become the bottleneck problem of CFD to exert its potential. Therefore, in this paper, the parameterized pre-process of combustor, the porous medium model, the centrifugal fuel injection atomization model and the post-process model of calculation results are studied, and the parameterized analysis system of combustors was developed.A study of parameterized pre-process of combustor was carried out for a certain type of reverse flow combustor and slinger combustor. A program developed by the secondary development tool UG_OPEN GRIP under UG, modeling by modular programming and modular design of geometry, which improves the ability of program in extending, updating and universality.An interface was created for a description method of geometrical characteristics to realize the modeling of complicated geometry.For meshing,we can creat,modify and edit the script file to make the rapid and accurate grid division come ture,so as to realize automatic meshing.Three simulation models of combustor were accomplished based on the Fluent software. The secondary development of the porous medium model was accomplished for the efficient and convenient simulation of the combustor with inclined multi-holes effusion-cooling structure by using the UDF and C language. The model could avoid the complexity of the combustor modeling, the limitation of grid number and computer, and reduce the pre-processing work. The developed model combined the theory of effusion-cooling technology and porous medium model.Then, the developed porous medium model was verified in a three-dimensional inclined multi-holes effusion-cooling structure, found the developed model can accurately get the distribution of the wall temperature and the calculation results were closed to the results which without the porous medium model.In the same way, the centrifugal fuel injection atomization model and the post-process model were developed with using the UDF and C language. The centrifugal fuel injection atomization model established the relations between the fuel export parameters and the structural parameters of the centrifugal fuel injection wheel and formed a DPM file for Fluent to import. The post-process model calculated the state parameters of combustor form monitor output files of Fluent and compared with the test results obtained relative error to save the manual calculation time.Finally, a parameterized analysis system of combustor was accomplished with the integration of the parameterized pre-process method, the porous medium model, the centrifugal fuel injection atomization model and the post-process model. Then, applied this system to a certain type of reverse flow combustor and annular combustor. The parameterized pre-process method was verified through the calculation of the reverse flow combustor and found that it could reduce more than 90% of the workload and the entity modeling and meshing results were reasonable. The porous medium model and the centrifugal fuel injection atomization model were verified by the simulation of the slinger combustor. The results showed that the porous medium model could have accurate simulation of the temperature distuibution of combustion chamber wall and they were closed to the experimental results. The centrifugal fuel injection atomization model could accurately simulate the actual effect of the fuel injection wheel, fuel distribution uniform and reasonable, and can modify the location of fuel injection, exiting diameter, velocity components and the flow rate of fuel flexibly.