The design and development of Stratospheric Airships for High-Altitude Long-Endurance missions (HALESAs) has generated interest worldwide. Conventional airships usually have a single-lobed axisymmetrical envelope shape. In contrast, several non-axisymmetric envelope configurations have been proposed for the HALESAs, such as flattened single lobed and multi lobed. This paper describes a methodology for carrying out a comparative analysis of a conventional HALESA and the multi-lobed HALESA designed for the same design mission. A sizing methodology which enables the estimation of its design parameters to meet some user-specified requirements has been developed for airships with envelopes of both these shapes. A Multidisciplinary Design Optimisation (MDO) approach has been followed in this methodology, which includes considerations from the disciplines of aerodynamics, energy, environment and structures. The study indicates that the envelope volume, solar array area and total mass of the single-lobed conventional airship are better than those of the tri-lobed HALESA. While the multi-lobed HALESA has the advantage of a flatter upper surface resulting in higher efficiency of the solar panels, the conventional airship has lower drag, which results in superior mission performance.

中文翻译：

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常规和三叶平流层飞艇的比较研究

用于高空长航时任务（HALESAs）的平流层飞艇的设计和开发引起了全世界的兴趣。常规飞艇通常具有单叶轴对称包络形状。相比之下，已经为 HALESA 提出了几种非轴对称包络配置，例如扁平单叶和多叶。本文介绍了一种对传统 HALESA 和为相同设计任务设计的多叶 HALESA 进行比较分析的方法。已经为具有这两种形状的外壳的飞艇开发了一种尺寸调整方法，可以估计其设计参数以满足一些用户指定的要求。该方法遵循多学科设计优化 (MDO) 方法，其中包括来自空气动力学、能源、环境和结构等学科的考虑。研究表明，单叶常规飞艇的包络体积、太阳能电池板面积和总质量优于三叶HALESA。多叶HALESA的优点是上表面更平坦，从而导致太阳能电池板的效率更高，而传统飞艇的阻力更低，从而具有出色的任务性能。