Overall Design And Numerical Thorough Flow Simulation Of Micro Turbine Engine

In recent years,with the continuous improvement of computer computing ability,it is possible to use more complex calculation methods to simulate the threedimensional full flow of aeroengine involving multi physical field coupling.The full flow numerical simulation method has the advantages of high precision and specialization in single component simulation,and also considers the interaction among the components of the real working point when the engine achieves flow balance,load balance and pressure balance.In this aspect,it has the ability that single component simulation does not have,and can quickly analyze the flow field and performance of the whole aeroengine,It is of great significance to improve engine efficiency,reduce flow loss and test cost.In this paper,the load balancing program is coupled with mature commercial software to simulate the full flow of a mature micro turbojet engine1)A general module is designed to meet the needs of micro turbine power generation system and micro turbojet engine by using modular design method,which is different from the traditional micro turbine power system design mode for single type of use demand.From the initial design stage,the universality and robustness of each module are considered,and the influence of design point performance on the performance of different power systems is analyzed separately.Based on the performance of the general module,the steady-state performance of the general module under various power system conditions is verified by self programming calculation.2)Based on the results of component design,the structure design of micro turbine power system is carried out.The whole structure design content and tail nozzle design content of micro turbojet engine are mainly introduced.According to the structural characteristics of micro turbojet engine prototype,the connection mode and shafting structure of engine components are determined,and the oil circuit structure and lubrication mode of engine are determined,In order to meet the working characteristics of micro turbojet engine,the designed engine was processed.3)Influenced by the turbulent combustion and the mixing process of cooling air in the combustor,the flow field at the exit of combustor(that is,the flow field at the inlet of turbine)has the characteristics of non-uniform temperature distribution.In order to solve this problem,this paper studies the combustion flow field in the flame tube and the internal flow field of the turbine under the condition of non-uniform inlet by using the numerical simulation method for the combination of annular recirculation combustor micro radial turbine and annular once through combustor axial turbine.4)Based on a mature commercial software,the full flow numerical simulation of KJ66 micro turbojet engine is carried out.The steady flow field of the whole engine is calculated by using Reynolds average method,and the load balance method is coupled to the full flow calculation,so as to obtain the flow field of the real common working point of the whole engine,The flow field obtained by full flow numerical simulation is compared with that obtained by single component simulation under the same conditions,and the difference between them is analyzed.