Analysis and retardation of helium permeation for high altitude airship envelope material

Abstract

Airships are fast gaining popularity as one of the most prominent modes of surveillance, reconnaissance and providing connectivity in remote areas. These airships work on the Archimedes' principle, and employ gases which are lighter than air to stay afloat in the atmosphere. These gases are the most critical and costly support element for the usage of such airships as the permeation of these gases through the envelope material limits the flight duration of the airship and further increases the cost associated with transporting and refilling of the airship, thereby limiting its utility. Engineering the material of the envelope, so as to be able to minimize the leakage of gas, becomes the most important challenge for engineers designing the airships. The traditional experimental techniques used to analyse the permeation through the laminate are known to be extremely sensitive to minor variations in temperature and pressure and involve specialized equipment, time and money. This paper proposes and discusses alternate Computational Fluid Dynamics based 2D and 3D approaches to analyse the permeation of the gas through the envelope material, particularly for high altitude airship applications. In addition to this, this paper proposes a method to determine the best suited material for the airship envelope through a qualitative and quantitative permeation analysis of different combinations of material options.