Simple method to predict balloon shape

Abstract

A numerical scheme to predict the shape of large scientific balloons is described. The method ignores elastic deformation and asymmetric folding. Results are presented for geometries where all the tension in the balloon fabric is carried meridionally and the circumferential stresses are assumed to be zero, during ascent, as well as at the design float altitude. Some results with envelopes with non-zero circumferential stresses and with caps fitted are also given. Brief comparison with the results of more complex numerical models, reported by other workers, suggests that the method yields nearly identical geometric solutions.