Design of a High-Altitude Long-Endurance Solar-Powered Unmanned Air Vehicle for Multi-Payload and Operations

Abstract

Several researches are being carried out at the Politecnico di Torino with the aim of designing a high altitude very-long endurance/unmanned air vehicle (HAVE/UAV). Being able to fly in the stratosphere (15 -20 km) and with an endurance of about 4 months offers an advantage and possibility that is presently not available with conventional aircraft or satellites. A computer program has been developed to design the platform. The change in solar radiation over a period of a year, the altitude, masses, and efficiencies of the solar and fuel cells, as well as the aerodynamic, structural, flight mechanics, and aeroelastic performances have all been taken into account. Extensive use has been made of high modulus graphite/epoxy when designing the structure in order to minimize the airframe weight, but also to guarantee the required stiffness and aeroelastic performance.A blended wing body (BWB) configuration has been selected for solar HAVE aircraft multi payload and operation (SHAMPO) with eight brushless electric motors, as the result of a preliminary design. The BWB solution has been designed according to the conventional procedures and airworthiness regulations. It seems to be the best compromise between performance, available surfaces for solar cells and volume for multi-payload purposes, compared to conventional design.Several profiles and wing plans have been analysed and optimized to achieve the best efficiency using the Xfoil and Vsaero computational fluid dynamics (CFD) software. A finiteelement method and a classical theoretical analysis was carried out using the Msc/Patran/ Nastran code to predict the static and aeroelastic behaviour of the SHAMPO. Aeroelastic analysis has been performed starting with a classical linear flutter analysis and considering an undeformed equilibrium condition. Classical linear flutter speed show as the airworthiness requirements has been achieved in the case of SHAMPO configuration. A preliminary non-linear aeroelastic model is introduced in the design process in order to deal with specific phenomena correlated with high static structural deflections occurring during standard flight conditions. Important flutter speed reduction (i.e. up to 42 per cent in special cases) are possible including such kind of phenomena.

Design and Manufacture of a Solar-Powered Unmanned Aerial Vehicle for Civilian Surveillance Missions

“…In this way, it is possible to arrange the photovoltaic cells without considerable deformations. This type of configuration can also be seen in Cestino (2006), Gao et al (2014) and Romeo et al (2007). On the other hand, new methodologies to optimize the construction of the aircraft were implemented following the global trend by applying manufacturing processes with composite materials.…”

“…Therefore, it has been established, according to survey data, that hybrid energy configurations exist linking various types of energy; among the different alternatives are: the combination of hydrogen fuel cells (LH 2 ) with Diesel Betancourth NJP, Villamarin JEP, Rios JJV, Bravo-Mosquera PD, Cerón-Muñoz HD fuels or gas turbines (Nickol et al 2007) and electric engines with solar cells (Brandt and Gilliam 1995;Romeo et al 2007). Consequently, one can opt for the tendency to use renewable fuels.…”

A study on Select Solar Cell’s Voltage Output at High Altitudes Using a Weather Balloon

“…Hundreds of balloons are sent to the upper atmosphere every year around the planet [1] and weather balloons have been utilized in many different aspects of physics research. Some of this research has involved measuring the cosmic rays at high altitudes [2] and studying the various effects of weather on electrical and magnetic properties of high altitude ranges under several solar conditions [3,4,5].…”

“…Since making the first solar cell in the late 1940s, the efficiency of single p-n junction crystalline silicon devices are now approaching the theoretical limiting efficiency of 37.7%. However, the new multiple layer solar cells have a theoretical limit of 86% It is well known that the design and the shape of the solar cell platform have a noticeable effect on the efficiency at high altitudes [1].…”

Structural Analysis of a Composite Target-drone

“…In addition, a limited number of papers on UAV structural design have been published. Romeo et al (1995Romeo et al ( , 1998Romeo et al ( , 1999Romeo et al ( , 2003, Cestino (2006), and Frulla and Cestino (2008) used composite materials to develop a high altitude long endurance (HALE) UAV and a solar powered airplane. Gadomski et al (2006) used composite materials to make a composite UAV and proposed an optimization method for the wing structure.…”