Design of Batteries for a Hybrid Propulsion System of a Training Aircraft

In this article, we propose the parameters of a battery that would be suitable for the conceptual design of a small training aircraft. The mass design of the battery is based on the requirements for real training flights performed by students in pilot training. Such a serial hybrid propulsion aircraft could be used in our UNIZA aviation, training and education center for pilot training. Due to socio-political pressures in reducing emissions generated by vehicles, there has also been massive research in the aviation industry in the field of hybrid and electric aircraft propulsion. In the introduction, the article deals with the energy sources used in aircraft propulsion. In hybrid propulsion, a combination of aviation fuel and electricity is used as the energy source. The required total energy must choose a suitable combination of these two energy sources. The biggest drawback of batteries that can be used in hybrid systems is their low energy density. Low energy density means that larger and heavier batteries need to be used to achieve the required performance, which is their main disadvantage. Therefore, it is necessary to find a suitable compromise between the hybrid’s percentage, i.e., the ratio between conventional and electric drive. We applied the hybrid aircraft system’s calculations to the real training flights to determine the necessary parameters of the hybrid aircraft suitable for pilot training. This calculation will help in obtaining an idea of the basic parameters of the hybrid drive and the battery parameters, which are necessary for particular applications in the training aircraft. The performed calculations of the hybrid configuration and, especially, the determination of the battery of the hybrid propulsion parameters provide the basic information necessary for the design of the hybrid system of a small training aircraft. These outputs can be used to determine the parameters of batteries that would be used in hybrid systems. A limiting factor to consider with hybrid aircrafts is that the aircraft must be charged on the ground before the flight, which poses interesting logistical and infrastructure problems at the airport.

Electric Aircraft Propulsion

This paper presents the state of the art in electric aircraft propulsion systems. The necessary reduction of greenhouse gas emissions on the global scale forces aviation engineers to search for ‘green’ solutions. Electric aircraft propulsion is a potential and relatively intuitive choice for a reduction of emissions in flight operations. This paper showcases four architectures of aircraft propulsion systems being now considered to utilise the advantages of electric propulsion with commercially profitable operating range and payload capabilities. One of the largest technological obstacles to the widespread use of electric propulsion in aviation is the low energy density of modern electric batteries. This paper presents the types of power supply which may achieve an energy density above the minimum threshold of 500 Wh/kg, and alternative onboard electrical power sources. The paper also shows novel designs of electric motors intended for aerospace applications. The final sections of this paper shows the implemented projects of aircraft with electric propulsion and the electric aircraft propulsion research projects underway around the world.