Chalmers University Technology
Electric aircraft become highly attractive in recent years owing to the advantage of zero greenhouse gas emissions such as CO2 and NOx, which are unavoidable for the use of fossil fuels. The propulsion systems of these aircraft are driven by electricity. Hence, battery technology is the primary factor limiting the development of electric aircraft. An obvious problem of batteries is the energy density, while it has not been completely resolved using the existing technology to date. To tackle this technical challenge, another effective way is to increase the efficiency of the propulsion system. Propellers are commonly adopted for such propulsion systems since their efficiency in general could reach 20% to 40% larger than classical turbine propulsion systems. Furthermore, given the fact that electric motors are scalable without losing the efficiency, distributive aircraft architectures that improve the aircraft aerodynamic performance can be reliably designed. Figure 1 shows several existing distributive electric aircraft architectures. As multiple propellers are integrated in the propulsion systems, the number of variables determining the aerodynamics are increased in consideration of propeller positions, power consumption, thrusts, and the interaction between the propellers and aircraft wing body. This suggests that the design envelope of the architecture parameters is very large. Design and optimization of such a complex propulsive architecture demands a very large number of numerical simulations. However, it is well known that time-consuming and high-costly simulations are commonly not acceptable for the early stage design in industry.