The reliability and safety of the pneumatic ducts are essential for flight safety.A beam element model of the duct system is developed and the factors that impact the stress performance of the duct system are investig...The reliability and safety of the pneumatic ducts are essential for flight safety.A beam element model of the duct system is developed and the factors that impact the stress performance of the duct system are investigated,such as stress check standards,flight acceleration,internal temperature and internal pressure.The results show that the stress synthetic method as the stress check standard can obtain the more safety design results.The maximum stress of straight pipe is affected significantly by the acceleration in a plane perpendicular to straight pipe,while the maximum stress of bend pipe is greatly affected by the acceleration in the direction perpendicular to plane of the bend pipe.Meanwhile,internal pressure has little effect on the maximum stress of bend pipe and straight pipe.Temperature has little effect on the maximum stress of bend pipe while has a big impact on the maximum stress of straight pipe.展开更多
Bleed air system is one of the most important components of air management system(AMS).It acts as transfer pipes responsible for air supply at high temperature and pressure.The thermal and flow performance of the blee...Bleed air system is one of the most important components of air management system(AMS).It acts as transfer pipes responsible for air supply at high temperature and pressure.The thermal and flow performance of the bleed air system is a key issue for the design of AMS since the characteristics of air source have a great influence on the anti-ice system,the environmental control system and other downstream system in need of high temperature pressurized air.Based on the one-dimensional lumped parameter technology,a computer analysis model of bleed air system is developed in order to analyze the thermal and flow behaviors of the nodal points in the pipeline network.The simulation are performed with a given flight assignment using the analysis model,and the results verify that the system meets the design requirements.展开更多
文摘The reliability and safety of the pneumatic ducts are essential for flight safety.A beam element model of the duct system is developed and the factors that impact the stress performance of the duct system are investigated,such as stress check standards,flight acceleration,internal temperature and internal pressure.The results show that the stress synthetic method as the stress check standard can obtain the more safety design results.The maximum stress of straight pipe is affected significantly by the acceleration in a plane perpendicular to straight pipe,while the maximum stress of bend pipe is greatly affected by the acceleration in the direction perpendicular to plane of the bend pipe.Meanwhile,internal pressure has little effect on the maximum stress of bend pipe and straight pipe.Temperature has little effect on the maximum stress of bend pipe while has a big impact on the maximum stress of straight pipe.
文摘Bleed air system is one of the most important components of air management system(AMS).It acts as transfer pipes responsible for air supply at high temperature and pressure.The thermal and flow performance of the bleed air system is a key issue for the design of AMS since the characteristics of air source have a great influence on the anti-ice system,the environmental control system and other downstream system in need of high temperature pressurized air.Based on the one-dimensional lumped parameter technology,a computer analysis model of bleed air system is developed in order to analyze the thermal and flow behaviors of the nodal points in the pipeline network.The simulation are performed with a given flight assignment using the analysis model,and the results verify that the system meets the design requirements.
