Engineering Calculation Method Of Pressure Response Time Of Pneumatic Pipeline

The air braking system is one of the commonly used braking modes for bus and truck.Its excellent performance ensures driving safety and braking stability of vehicles,and the pressure response time of the braking system is an important factor for vehicles travel safety.As an important part of the air braking system,pipeline is an important influence factor of the pressure response time of the system.Therefore,accurate analysis and calculation of pressure response time of pipeline are of great significance.In this paper,theoretical analysis,simulation analysis and experimental verification methods are used to systematically study the pressure response time of pneumatic pipelines.The main research works of the paper are as follows:(1)For pneumatic pipelines,the Cubic Interpolated Profile method(CIP)is used to solve its theoretical model,and its discrete model of the pressure response is obtained by considering the staggered grid.Referring to the application background of the pneumatic pipeline,the boundary conditions of single pipeline inflation and deflation and shunt pipeline speed distribution are set.The pressure response curves of pipelines are obtained by MATLAB simulation.(2)The influence law of pipe length,pipe diameter,inlet condition,initial pressure and supply pressure on pressure response time is analyzed by using fuzzy-gray relational degree analysis method.The experimental scheme of pressure response of the pneumatic pipeline is designed by using the response surface method in the experimental design method.The influence law of experimental parameters on pressure response time is analyzed by multi-parameter analysis method,which provides the experimental support for the derivation of the calculation formula.(3)The response surface method is used to fit the experimental data,and then the polynomial calculation formula of pressure response time is obtained,and the calculation formula is optimized based on the influence law of parameters.The form of the calculation formula is derived by means of dimensional method,and the undetermined coefficient is determined by fitting the experimental data,and the calculation formula is optimized by changing the undetermined coefficient.(4)With reference to national standards,the boundary conditions of gasholder and brake chamber inflation are set,and the calculation method of the pressure response time of the pneumatic pipeline with the container is obtained,and the validity of the method is verify by the test platform of a commercial vehicle air braking circuit.This paper takes the calculation formula of pressure response time as the ultimate goal,calculates and analyzes parameters that affect the pressure response time of the pneumatic pipeline,and derives the engineering calculation formula of the pressure response time of the pneumatic pipeline.This provides the theoretical basis for the selection of the pneumatic pipeline and provides the theoretical reference for the design of the air brake system.