Research On Airtight Detection Method Of Fuel System

With the rapid development of the modernization of the national defense industry,the quality requirements of aircraft products are constantly improving.Airtight detection,as one of the methods of sealing inspection,is playing an important role in ensuring product quality,saving energy and so on.In this paper,we have researched on the airtight detection method of the aircraft fuel system.Firstly,according to the technical requirements of fuel system,we put forward the airtight detection method,which is based on pneumatic servo technology,described its working principle,the formulas of leakage rate and pressure difference compensation,analyzed the stages of the fuel system airtight detection process in detail.Secondly,according to the airtight detection process of the fuel system,we have established the mathematical model of the pressure generation loop and thermodynamics,carried out the numerical simulation.Through the research of the airtight detection pressure generation loop,we have analyzed the working characteristics of the suction and exhaust,the correctness of the mathematical model was verified by experiments.The influence of temperature,leakage area,test pressure and the volume of the test chamber on the airtightness was analyzed by numerical simulation of the thermodynamics process,and the results show that if the volume of the cavity is measured,the gas temperature changed small when the leakage is miniature,and the change of the gas temperature is increasing with the increase of the test pressure,and the required regulation time is longer.Finally,the prototype of fuel system airtight detection was developed and its control application was programmed.High and low pressure air-tightness tests were implemented on the cavity with different leakage area.The experimental results show that the temperature compensation has a good effect on reducing the gas leakage rate error.The airtight detection of the fuel system achieves the intended target.This paper has laid a good foundation,which is helpful to promote the development and progress of the airtight detection technology in the field.