Conceptual design of the next generation gas turbines : Modelling of a hybrid electric mixed turbofan for a trainer aircraft

Sammanfattning: To mitigate climate change, all sectors must contribute their part. Electric propulsion system is a promising approach to reduce emissions from the aviation industry. A major challenge is however the low energy density in today’s battery technology. Even with today’s leading li-ion batteries, the specific energy density in jet fuel is 48 times larger. Because of the low energy density in any battery technology today, hybrid electric propulsion system could be a bridge between conventional and fully electric propulsion systems. The purpose of this degree project is to explore different designs of a parallel hybrid electric mixed turbofan to minimize the impact aircraft have on the environment. The engine has been designed in Modelon Impact and MATLAB has been used to evaluate the thrust requirement and, the performance and weight calculation of the electrical power system. Furthermore, the conventional engine was validated against GasTurb. Three different designs were evaluated, i.e., design #1 (reference engine with hybridization), #2 (decreased OPR) and #3 (increased BPR and decreased FPR) with two different weights of the electrical power system. None of the designs showed a reduction in terms of the total fuel consumption during the whole mission profile. However, design #3 showed the most beneficial results in terms of reducing the specific fuel consumption and could reduce the fuel consumption in the climb segment the most among the three different designs.