Performance calculation of vent system for a maneuvering airplane

The vent system must keep the tank pressure within the permitted limits during maneuvering and its performance validation is one indispensable process in the course of system design. On the bases of network algorithm and time differential method, a calculation model is studied for air pressure inside the fuel tanks and a simulation method of vent system in maneuver course is presented. Finally a numerical example is given for a certain type of aircraft, the variations, in one maneuver course, of air pressure inside the five fuel tanks are given, and a comparison is made between the pressure difference in-and-outside fuel tank and the maximum pressure limits that the fuel tank can resist. The predicted results are all agreed well with the practical situation, i.e., the pressures in the all five fuel tanks are close to the pressure at the inlets of vent system, and the pressure difference is less than the maximum pressure limits. It validates that the vent system satisfies the design standard and the calculation model presented in this thesis is approved to be available.