آناليز، مدلسازي و تست شير نيوماتيكي ترمز لكوموتيو

Independent brake valve, is a diaphragm pnematic valve with low out-flow and self lapping property. By moving valve handle, the valve delivers reserved compressed air to other sections of the system. The pressure of output flow is adjusted based on pre-set pressure of a spring which is usually between 45-50 psi. In this paper, first, the valve is desribed and analyzed based on its functionality. Then, the mathematical equations of various sections of valve are presented. After that and based on those equations, the mathematical model of the whole valve is derived. To evaluate the model, the reults obtained from simulation are compared to the experimental results. After validation of the model, it is used as a reference to evaluate the functionality of the valve at different operating conditions. In general, investigation on the steady state and also transient response of the valve is the main objective of this research.