Optimum Design Of Injection Ring For A Micro-Turbojet Engine

Micro-miniature Turbojet Engine is an important branch in the field of aeroengine.Due to its light weight,small size,large thrust-to-weight ratio and high performance,it is widely used in military and civilian fields as a power plant,such as Cruise missiles and target drone,Unmanned Reconnaissance Aircraft(Spy drones),Small Personal Air Vehicle and mapping drones.In the development of various Micro-miniature Turbojet Engines,researchers are striving to reduce the fuel consumption and improve combustion efficiency while pursuing The Micro-miniature Turbojet Engine with greater thrust.Low fuel consumption and high combustion efficiency mean good economic performance,reduce pollution to the atmospheric environment,and improve the overall performance of The Micro-miniature Turbojet Engine.This paper mainly studies the fuel injection ring of a Micro-Turbojet Engine.The fuel injection ring is an important part of the fuel system.In the oil supply test,it is found that the fuel flow at the outlet of each injection needle with equidistant equidistant distribution on the fuel injection ring is uneven.The problem,the uniformity of the injection quantity determines the uniformity of the temperature field of the combustion chamber,and the uniformity of the injection quantity will also affect the life of the latter stage turbine.The local rich or poor oil will affect the combustion chamber.The combustion efficiency,especially the rich oil condition,can damage the turbine blades and shorten the life of the turbine structure;therefore,it is necessary to optimize and improve the structure of the fuel injection ring.The fuel injection ring is an important part of a Micro-Turbojet Engine.At present,the research and analysis on the uneven injection quantity of the injection ring of a MicroTurbojet Engine is carried out.The data is analyzed and the relevant research experience at home and abroad is combined to simulate the numerical simulation.Analyze and give the structure optimization scheme;this paper intends to compensate the pressure loss by using the unequal diameter injection needle structure scheme to ensure the uniformity of the fuel injection volume of each injection needle;the fuel injection ring is built by Catia 3D modeling software.The model uses Boolean operation to obtain the fuel flow field inside the fuel injection ring.The CFX software is used to numerically simulate the threedimensional flow field of the fuel inside the fuel injection ring during the oil supply test,and calculate the outlet fuel flow value of each fuel injection needle on the fuel injection ring body.The exit speed and the pressure change of the entire internal flow field of the fuel injection ring are finally compared with the oil supply test.Based on the simulation method,the results show that the unequal diameter injection needle structure scheme can better improve the injection volume unevenness of the injection ring,reduce the fuel consumption rate,and improve the combustion efficiency of the combustion chamber.According to the obtained calculation results,it can lay a foundation for studying the internal flow field of the fuel injection ring and making analysis,and provide reference for the design of the Micro-miniature Turbojet Engine in the future.