Purpose

This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by.

Design/methodology/approach

The design code of aerostat involving structure, aerostatics, aerodynamics and stability has been developed using MATLAB®. The design code is used to obtain the baseline configuration for a tactical aerostat mission by using the statistical values of the hull fineness ratio and the fin parameters of in-service aerostats. The effect of the design variables that include the hull fineness ratio, fin area and fin position on the aerostat mass and blow-by is determined through sensitivity analysis. The aerostat is optimized with an objective function of minimization of mass for the bounded values of design variables and taking blow-by limit as a constraint.

Findings

This study reveals that the simultaneous optimization of the aerostat hull fineness ratio, fin area and fin position results in an improvement in the design. The aerostat design with optimum values of these parameters helps in a reduction in its size and mass without compromising the blow-by limits.

Research limitations/implications

This study has been conducted by keeping the hull shape constant by selecting standard National Physics Laboratory envelope shape. The aerodynamic model used in the design code is based on empirical relationships that can be improved in future studies that can use high fidelity aerodynamic models using CFD based surrogate models.

Originality/value

The previous studies on optimization of aerostats are limited to hull envelope shape only, whereas this paper presents the optimization of the hull and fin together. The optimized configuration obtained has a reduced mass and can operate within the specified blow-by limits.

中文翻译：

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船体细度比和翅片参数对系留浮空器优化的影响

目的

本文旨在优化系留式浮空器的质量以实现最佳船体体积，并优化尾翼以产生气动升力以减少窜气。

设计/方法/方法

使用MATLAB®开发了涉及结构、空气静力学、空气动力学和稳定性的浮空器设计规范。该设计规范用于通过使用船体细度比和在役浮空器尾翼参数的统计值来获得战术浮空器任务的基线配置。包括船体细度比、翅片面积和翅片位置在内的设计变量对浮空器质量和窜气的影响是通过灵敏度分析确定的。浮空器通过设计变量有界值的质量最小化目标函数进行优化，并以漏气限制为约束。

发现

该研究表明，同时优化浮空器船体细度比、鳍片面积和鳍片位置可以改进设计。具有这些参数最佳值的浮空器设计有助于在不影响漏气限制的情况下减小其尺寸和质量。

研究限制/影响

这项研究是通过选择标准的国家物理实验室外壳形状来保持船体形状不变的。设计规范中使用的空气动力学模型基于可以在未来研究中改进的经验关系，这些研究可以使用基于 CFD 的替代模型的高保真空气动力学模型。

原创性/价值

以前对浮空器优化的研究仅限于船体包络形状，而本文提出了船体和尾翼的优化。获得的优化配置减少了质量，并且可以在规定的漏气限制内运行。