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Highlights • A multidisciplinary model of solar-powered hybrid airship is carried out. • A mission-based flight strategy of the hybrid airship is presented. • Multi-objective optimization is conducted to obtain the optimal design set. Abstract This paper presented a multidisciplinary optimization methodology of a high altitude solar-powered hybrid airship. A multidisciplinary model of the hybrid airship is proposed including the geometry, aerodynamics, structures, propulsions and energy consisting of the photovoltaic array and energy stored system (ESS). To achieve a continuous flight and reduce the total mass and energy cost, a multi-phase strategy including the climb, daytime cruise, glide and nighttime cruise is proposed. The mission-based optimization is achieved through an enhanced collaborative optimization and the result shows a large decrease in the total mass compared with a baseline design. Since the flight altitude has a great influence on the hybrid airship with the multi-phase strategy, a multi-objective optimization achieved by NSGA-II (Non-dominated Sort Genetic Algorithm-II), is carried out to discuss the design tradeoffs in different altitudes. The result also indicates that the multi-objective optimization provides a solution set so that the optimal design of the hybrid airship in different flight altitudes could be obtained. [ABSTRACT FROM AUTHOR]

The increasing application of hybrid airships which have been recently proposed as high altitude platforms, makes it necessary for research into the thermal performance of such airships that possess a photovoltaic module array(PVMA). In this study, a simplified thermal model of a high-altitude hybrid airship with a PVMA, was proposed that included direct solar, infrared, reflected, and scattered radiation and convective heat transfer. Based on computational fluid dynamics(CFD), a simulation methodology, using a user defined function(UDF) program, was introduced to investigate the PVMA's thermal effects on the hybrid airship. A ground experiment was also performed to validate this numerical method's effectiveness. Further simulations and discussion of temperature and velocity distributions of the hybrid airship's internal helium were conducted. The results showed that the PVMA atop the hull had large effects on the hybrid airship's thermal performance. The temperature distribution of the envelope varied greatly during the day and night because of the PVMA's influence as well as the internal helium flow. In addition, forced convection had little influence on the PVMA's output performance, which was analyzed in detail. [ABSTRACT FROM AUTHOR]

This paper aims to develop a high-altitude solar-powered hybrid airship, which combines aerodynamic lift and buoyancy with buoyancy force and cruises continuously. A multi-lobed configuration is employed and the solar irradiance and photovoltaic array model are proposed. After introducing all the parts mass of the hybrid airship and design procedure, an optimal problem with the constraint of energy and the equilibrium between buoyancy and weight are proposed. Through a hybrid optimization search method, the solution is obtained and the sensitivities of geographical location and seasons are discussed. The results show a comprehensive influence of the constraint both in latitude and wind field environment. [ABSTRACT FROM AUTHOR]

The existence of a platform at the stratosphere is expected to be the role to gain a foothold in space. When the platform is employed airship in, it is transported by advection due to its light-weight body. Thereupon, a mooring of platform is reasonable in order to incarnate fixed-point platform. Conception of a captive platform system is similar to the Rockoon one which rendered remarkable services for the space observation of the early days. Therefore, the application of captive platform system to the launch site is highly expected in order to realize the space transportation system with a large quantity and high frequency. In this study, the motion of a captive platform system constructed from an airship and a tether is analyzed in order to ensure that the motion of a captive platform system is practically incarnated. Moreover, the sensitivity of aerodynamic performance of the airship is observed. Consequently, the practically incarnated motion of a captive platform system has been identified under the condition of the storm environment. Furthermore, the reduction of the advection distance driven away by the storm has been quantitatively indicated under the different condition of aerodynamic performance of the airship. [ABSTRACT FROM AUTHOR]

• Proposed multidisciplinary design optimization approach for hybrid airship. • Developed Kriging-based surrogate model to evaluate envelope drag coefficient. • Particle Swarm Optimization technique hybridized with Pattern Search method. • Sensitivity analysis of energy storage devices. In the recent years, there has been a lot of interest in developing hybrid airships as aerial platforms for various applications because of their several advantageous features. This paper presents a multi-disciplinary design optimization based methodology for an airship with a tri-lobed envelope. The proposed methodology involves five disciplines, viz., Geometry, Environment, Energy, Aerodynamics and Structures. To reduce computational complexity involved in evaluating the aerodynamic characteristics of the tri-lobed envelope, a Kriging-based surrogate model was developed to estimate the envelope drag coefficient and coupled to the optimization framework to achieve the optimal solutions for different operating conditions. The surrogate model predicts the drag coefficient of the tri-lobed envelope with less than ± 3% error with respect to the results obtained through CFD. Since the problem follows a multi-disciplinary design approach, a composite objective function is formulated based on volume of the envelope, area of the solar array, and total mass of the airship, which isminimized using Particle Swarm Optimization (PSO) Algorithm. This study reveals that for meeting the same mission requirements, a tri-lobed airship powered by regenerative fuel cells requires half the volume and 33.5% lower solar array area, and has ~ 46% lower mass compared to the one powered by rechargeable batteries. [ABSTRACT FROM AUTHOR]