Low-altitude scaled similarity analysis and flight tests of near space airships with pressure resistance mechanism

In this paper, considering the low cost and high effectiveness-cost ratio of near space airships, as well as the insufficiency of theoretical methods for verifying space-ground equivalents, flight control technology validation of a typical airship was considered, and a method for describing the airship motion characteristics is presented in detail. According to the similarity and π theorems, dimensional analysis of the prototype airship's motion characteristics was completed, similarity criteria were tabulated, and the similarity index was determined. The design of the scaled parameters under the single-value constraint of “geometric similarity, kinematic similarity, and dynamical similarity” between the prototype airship and its low-altitude scaled model was performed, and a low-altitude scaled flight test platform and flight test were developed. Theoretical methods for the similarity analysis of the prototype airship and its low-altitude scaled model, as well as the basics of flight test engineering applications, were systematically introduced, describing a low-cost, repeatable low-altitude scaled flight test verification method for key technology verification of high-cost and high-risk near space airships. This study provides a foundation for follow-up studies of relevant similar theories and applications.