Research On Conceptual Design Optimization Method For Stratosphere Airship

As a typical lighter-than-air vehicle,the stratospheric airship has an enormous,yet untapped potential as low-speed,or even steady platforms for various applications,such as reconnaissance,surveillance,telecommunication,broadcasting relays,region navigation,environmental monitoring,disaster aid,scientific exploration,and so on.With the rapid progress of airship technologies,conceptual design plays a key role in the development of the stratospheric airship.For the purpose of solving the conceptual design application problems and further developing the new theory and methods,taking the system research as the background and stratosphere airship development as the research object,this dissertation carried out explorative study on the key technology of the conceptual design,which mainly includes the following several aspects:In this paper,aiming at the capability of conceptual design and simulation analysis based on stratosphere airship.The conceptual design composition scheme is defined,which is on the basis of tactics and technology norm.According to discipline area,the models of the outside size,aerodynamic,propulsion,weight,and energy disciplines are discussed in detail,which are divided into three subsystems,including aerodynamic/propulsion,weight,and energy subsystem.Moreover,the theory foundation of stratospheric airship conceptual design is provided.According to mission requirement,the design object is to find a feasible airship,which is with minimum total mass and satisfied the constrains including three balances: the balance between the energy supply and the energy requirement,the balance between mass and buoyancy,and the balance between drag ant thrust.The Simulated Annealing Particle Swarm Optimization(SAPSO)algorithm is used to optimize the parameters and optimized stratospheric airship design is gained.The sensitivity of the optimization results with the airship’s half length,slenderness ratio and the paving solar angle is analyzed.The optimization result,as a basic design program,is gained.Moreover,a reference of stratospheric airship program demonstration and design is provided.The structure and technical characteristic of stratospheric airship regenerative energy system are introduced.In this paper,power consumption of stratospheric airship and energy balance day and night are analyzed.In addition,visually simulated with the solar irradiance model is built and results verified energy balance day and night could achieve.Moreover,the pivotal technical parameters of energy system affecting energy system design are analyzed.Results verified power density of lithium ion battery,transforming proportion of solar cells and charging proportion of lithium ion battery are most pivotal technical parameters of regenerative energy system in stratospheric airship’s conceptual design.Importantly,a reference of stratospheric airship energy balance analysis program demonstration and energy system design is provided.Aiming at the multidisciplinary design optimization(MDO)of stratospheric airship,collaborative optimization(CO)algorithm is led into.Execution procedure and feature of response surface approximation in collaborative optimization(CO/RSA)is analyzed and building method of RSA is introduced.In this paper,multidisciplinary models of stratospheric airship are built and the coupled information in subsystem analysis is supplied by the RSA.In addition,the system optimization model and three subsystems,including aerodynamic/propulsion,structure,and energy subsystem,are discussed in detail.The design object is to find a feasible airship based on CO/RSA,which is with minimum total mass.The optimization result is compared with basic design program,which verifies the rationality of MDO and CO/RSA in stratospheric airship’s conceptual design.The related key technical problem for stratosphere airship conceptual design was studied in this dissertation.The results improved the research on systemic parameter design method,key technology of regenerative energy system and MDO method of stratosphere airship.Moreover,a reference of stratospheric airship program demonstration,key technology analysis and design method are provided.