Optimal Energy Management Strategies and Mission Profiles for a generic Hybrid Aircraft

The present paper shows the main characteristic of a numerical simulation tool, developed in the framework of the European H2020 project MAHEPA, to estimate optimal flight performance of a generic aircraft featuring a Hybrid powertrain. The purpose of the study is to determine optimal flight trajectories together with optimal power controls when a powertrain with multi-energy or multi-power sources (as the case of a generic hybrid one) is considered. For this purpose a complete new software has been developed, which is composed by three main parts: a mission performance “analyser” where the system dynamics of the problem is determined and it solves the aircraft Equation of Motion; a powertrain simulator that determines the operating conditions of the powertrain components and it ultimately computes the consumption of each energy source; a numerical algorithm that optimizes the aircraft control variables to determine both the optimum flight trajectory and the power management according to a certain objective functions and a variety of constraints. Different study cases are discussed when two existing flying hybrid aircraft are considered: a Hybrid-Electric (HE) Pipistrel Panthera aircraft and a Fuel-Cell hybrid (FCH) Pipistrel HY4. Results are presented also depending on the capability to simulate the entire mission as a whole (Single-Phase approach) as well as through the distinction of different flight segments as in the case of the Multi-Phase approach. In addition, two different resolution algorithms are tested in order to evaluate what are the aspects that might dictate the selection of the most suitable one.