Search Results

Advanced modeling and simulation techniques are becoming more important in today's industrial design processes and for aircraft energy systems in specific. They enable early and integrated design as well as validation of finalized system and component designs. This paper describes the main methods and tools that can be applied for different phases of the energy design process. For demonstration, the object-oriented modeling language Modelica was chosen, since it enables convenient modeling of multi-physical systems. Based on this standard, common modeling guidelines, a modeling library template, and common interfaces have been provided. A common modeling infrastructure is proposed with considerations on additional libraries needed for local tasks in the energy design process. The developed methods and tools have been tested by means of some predefined use cases, which are performed in cooperation with diverse aircraft industrial partners.

Intelligent software functions for energy management form a crucial element for aircraft electrical and thermal systems. In the electrical system, these are currently electrical load or power management functions that can cut and reconnect loads based on fixed priorities. The main aim of these functions is to prevent overload in failure mode of electrical generators, for example if one generator fails and another one has to take over its loads. For more-electric or all-electric aircraft, these functions should also cut loads during normal operation, since the electrical systems will not be sized to simultaneously provide maximum power to all loads. Additionally, energy management functions shall deal with multiple, parallel sources and should split power off-take in a way to reach maximum system efficiency. This paper provides an object-oriented tool and a method that enable a more intuitive development of an energy management function using economic models.

Aiming at the global energy optimization of aircraft, the More Electric Aircraft (MEA) concept becomes more interesting for the aeronautical industry. The MEA concept is based on utilizing electric power to drive aircraft subsystems that historically have been driven by a combination of hydraulic, electric, pneumatic and mechanical power transfer systems. The development of the future MEA systems is a challenging task: the system integration is becoming a central topic. In all phases of the system development process, the respective subsystems within the MEA will be treated in a highly integrated manner to achieve optimum efficiency and performance at aircraft and systems level. Concerning the electric network in the future MEA, advanced design and analysis methods based on mathematical models are required to face the potential issues accompanying the MEA. For this purpose, the use of advanced modelling and simulation technologies is a key success factor.

The thermal inertia of aircraft cabins and galleys is significant for commercial aircraft. The aircraft cabin is controlled by the Environment Control System (ECS) to reach, among other targets, a prescribed temperature. By allowing a temperature band of ± 2 K instead of a fixed temperature, it is possible to use this thermal dynamic of the cabin as energy storage. This storage can then be used to reduce electrical peak power, increase efficiency of the ECS, reduce thermal cooling peak power, or reduce engine offtake if it is costly or not sufficiently available. In the same way, also the aircraft galleys can be exploited. Since ECS and galleys are among the largest consumers of electrical power or bleed air, there is a large potential on improving energy efficiency or reducing system mass to reduce fuel consumption of aircraft. This paper investigates different exploitation strategies of cabin and galley dynamics using modelling and simulation.