Session: 05-02-01: Advances in Aerodynamics and Aerospace Propulsion Systems

Paper Number: 145240

145240 - Power System Analysis of Solar and Hydrogen Fuel Cell Powered Evtol Uav 

As the demand for Advanced Air Mobility (UAM) increases, so does the research interest in electric Vertical Take-off and Landing (eVTOL) Unmanned Aerial Vehicles (UAV). The eVTOL UAV configuration is described as the configuration in which the UAV takes-off and land vertically using its multiple lifting motors, while its forward flight is achieved using its forward flight motor. For this configuration to work, a well-designed wing is required to produce the lift during forward flight phase. The eVTOL appears to be more attractive due to their wide scope of applications such as in logistics, transportation, surveillance, healthcare, and policing, to name a few.

At the Technology Innovation Institute (TII), Abu Dhabi, a parametric study is conducted to assess a propulsion system that integrates photo-voltaic (PV) with a hydrogen fuel-cell system powered electric vertical take-off and landing (eVTOL) unmanned aerial vehicle (UAV). The eVTOL is powered by batteries and has an endurance of 90 mins and a payload of 2 kg. The aim of the study is to enhance the performance of the eVTOL, thus, studying a new power system to improve the overall performance of the eVTOL. Hydrogen fuel cells have been studied and have shown to provide high energy output per unit mass. The energy output of the fuel cell depends on the amount of hydrogen and oxygen supplied. Nonetheless, forward flight phase operates on relatively low power, hence, solar panels plus batteries are suitable for such conditions. Such an integrated PV-fuel cell power system is ideal because it compensates for the battery shortcoming, as batteries need charging once the stored energy is consumed. While the UAV is performing the flight, the PV panels power is directly used by the forward flight motor to generate the thrust for forward flight. Simultaneously, the energy is stored in the battery, which is to be used when the solar flux is not available.

Implementing the suggested power system results in an improved UAV performance in three crucial characteristics, namely endurance, payload, and hover-time. These improvements hold significant implications for aerial surveillance, cargo transportation, and other relevant industries relying on UAV technologies. Each of the specified characteristic enhancements serves in its respective mission. In this study, all three cases are broken down into subsystems, specifications, and operating conditions. The paper covers a comprehensive analysis involving modelling, simulation, aerodynamics, and experimental data. Moreover, the critical case of the system, that is when the sun is rising or setting, cloudy conditions, and rainy weathers, raise an issue in the calculations as equations assume optimal circumstances. The study shows that using PV-fuel cell integrated system, the endurance can be increased from 90 minutes to 180 minutes. The payload provision can be maintained to 2 kilogram while the structural changes ramin to a minimum.  

The findings of this study demonstrate the feasibility and potential of solar and hydrogen fuel cell-powered eVTOL UAVs as a viable alternative to conventional fossil fuel-based aerial platforms. This research contributes to the development and understanding of hybrid power systems advantages and capabilities. Also, contributes to the advancement of sustainable aviation technologies and offers insights into the future of eco-friendly aerial systems.

Presenting Author: Nouf Al Mesafri Technology Innovation Institute

Presenting Author Biography: Nouf Al Mesafri is a senior associate researcher at Technology Innovation Institute in Abu Dhabi, United Arab Emirates.
She is working on novel UAV propulsion and power systems for the past 2 years.

Authors:

Nouf Al Mesafri Technology Innovation Institute
Majed Al Hammadi Technology Innovation Institute
Sayem Zafar Technology Innovation Institute
Gustavo Santos Technology Innovation Institute