Design and Reliability Analysis of a Series/Parallel Hybrid System with a Rotary Engine for Safer Ultralight Aviation

Abstract

The conventional powertrain for ultralight aviation consists of a fixed pitch propeller connected to an internal combustion engine (ICE). Since ICEs have a limited thermal efficiency (<40%), new and more efficient powerplant configurations have recently been proposed in the scientific literature by adopting hybrid electric solutions. Hybridization has the additional benefit of increased safety thanks to redundancy. This is a very important issue in ultralight aviation, where a high percentage of accidents are caused by engine failure. In a previous investigation, the authors proposed the design of a series/parallel hybrid electric power system to increase safety and optimize fuel economy by controlling the engine working points during flight. A new powertrain, derived from an automotive Honda i-MMD system, is analyzed in this study and a reliability analysis is performed to underline the improved safety obtained with the proposed system.

Power-Split Hybrid Train Configuration Design Based on a Single-Row Star Row

“…The range of the planetary row member characteristic parameters was [1.5, 3], whereas the drive system transmission ratio range was [0, 5]. Equations ( 4) and (6) show that the ratios of the electrical power to the engine power for the two motors in the input and output distribution configurations were opposite each other. The numerical simulation results obtained by taking the absolute value of the ratio from the numerical analyses are shown in Figure 4.…”

“…The public praised the Prius for its exceptional fuel-saving capabilities when it was introduced for mass production in Japan in 1997 [4,5]. Donateo [6] proposed the design of a series/parallel hybrid electric power system to increase safety and optimize the fuel economy by controlling the engine working points. Li [7] presented a novel composite power-split hybrid system based on two planetary gear sets for commercial vehicles.…”

Analysis of prospects for the use of hybrid power plants in vertical takeoff and landing aircraft

“…Таким чином, забезпечується доволі висока паливна ефективність двигуна, а його робочий ресурс може бути подовжений. Крім того, це розширює можливості у проєктуванні, так як механічна відокремленість ДВЗ від повітряного гвинта у послідовній гібридній конфігурації дає можливість його оптимального розташування у літальному апараті, тому що енергію до компактного електродвигуна, який механічно з'єднаний із повітряним гвинтом, можна передавати за допомогою гнучких електрокабелів[8].Однак, послідовна гібридна конфігурація має свої недоліки. Серед них є доволі низька ефективність системи, оскільки під час перетворень енергії в численних системах, відбуваються значні втрати потужності, що суттєво знижує кінцевий ККД.…”