Modeling and simulation analysis of an airship’s leveling process during non-forming ascent

Purpose The leveling process is a critical metric during the non-forming ascent phase, yet research in this area remains insufficient. This paper aims to propose a leveling model based on the correlation between leveling and volume expansion to address this issue. Furthermore, the effects of the leveling process on vertical velocity, temperature and pressure differential are analyzed, refining the prediction of the non-forming ascent for airships. Design/methodology/approach The leveling model is integrated into the thermal-flight dynamic coupled prediction model. Variations in temperature, velocity and altitude during the ascent are analyzed. The validity of the model is validated by comparing results with those of other scholars. Furthermore, the effects of different trigger volumes and leveling rates are investigated. Findings The leveling process increases the vertical projection area and reduces the climbing velocity. For an airship with a volume of 8,578 m³ and a ceiling height of 19.5 km, the preformed minimum vertical velocity is 18.7% to 40% lower than that of the nonleveling and the forming velocity is 20% lower. This forms a “step” in the velocity peak, which is strengthened as the leveling is achieved more quickly and earlier. Additionally, it also reduces the volume expansion, delays the initiation of super-pressure and alleviates the “supercooling” phenomenon, resulting in a helium gas supercooling temperature during forming that is 16% higher. Originality/value A leveling model is presented for the non-forming ascent of airships. At the same time, both the supercooling phenomenon and the vertical velocity undergo “step” variations. These findings provide insights into the lateral control and pressure differential control of airships, as well as the prevention of cold adhesion during the ascent process.