Conference Year
2018
Keywords
airborne compressor, dynamic model, charging process, high altitude
Abstract
An air tank can be inflated with compressed air at anytime if the aircraft is equipped with an airbone compressor. . The different inlet altitude conditions and residual tank pressures both make it difficult to plan strategy about air tank filling. This paper studied the charging performance of the filling process in these complex working conditions, and proposed an inflating strategy of airborne compressor. A dynamic model is constructed to simulate the filling process of a multi-stage compressor with finite interstage volume. It takes 6 minutes to fill a tank with 2.0L volume from 0.101 MPa to 35 MPa, and startup process merely lasts 6 seconds. The experiment on the compressor was developed on the ground. The results validated with simulation values and shared similar evolution regularity of the pressure. The filling process at high altitude has been simulated. When residual bottle pressure is atmospheric pressure, with the altitude increasing from 0 km to 20km, the charging time increases from 6 minutes to more than 2 hours. Besides, the charging time is proportional to the residual pressure with a negative slope at a certain altitude. The mean torque in startup process declines with altitude rise, which proves filling at high altitude does not heavy the compressor’s load, as well as the electric machine control difficulty. Based on simulation results, a feasible working area satisfying ejection demand is proposed, which can be used to determine the charging time under any filling condition. In order to inflate the tank in thirty minutes, this airborne compressor must work under 19.7 km.