Defrosting Characteristics of the Cockpit Windshield of Manned Airships

Abstract

Frost covering of the cockpit windshield will seriously obstruct the driver’s vision and even affect flight safety of the low-altitude manned airship. To solve the problem, this paper proposes a rapid defrosting strategy using hot gas injection method. The influences of the air inlet type, air temperature, air velocity and air angle on the defrosting characteristics of the transparent windshield are investigated and the defrost characteristics of the manned airship are obtained by fluid dynamics simulation. The result shows: (1) Defrosting effect of single inlet is not as good as double inlets. The defrosting area of the double inlet is relatively large, mainly concentrated at both ends of the windshield. (2) The effect of air supply temperature on defrosting effect of windshield surface is more significant when double air supply inlets are used. But when the air supply temperature reaches a certain value and continues to rise, the defrosting time does not change much, so there is an optimal air supply temperature range. (3) The higher the air supply velocity is, the shorter the phase transformation time of frost layer is and the faster the melting velocity is. Considering energy consumption and defrosting characteristics, the optimal air supply velocity is about 6 m/s. (4) When the angle between the air supply direction and the horizontal plane of the bridge near the windshield is 100°, the frost layer has the shortest melting time.