Refine Your Search

Search Results

Viewing 1 to 4 of 4
Technical Paper

Towards a Model-Based Energy System Design Process

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.
Technical Paper

Model-Based Thermal Management Functions for Aircraft Systems

This paper describes a novel Thermal Management Function (TMF) and its design process developed in the framework of the Clean Sky project. This TMF is capable of calculating optimized control signals in real-time for thermal management systems by using model-based system knowledge. This can be either a physical model of the system or a data record generated from this model. The TMF provides control signals to the air and vapor cycle which are possible sources of cooling power, as well as load reduction or shedding signals. To determine an optimal cooling split between air cycle, vapor cycle, and its associated ram air channels, trade factors are being used to make electrical power offtake and ram air usage (i.e. drag) comparable, since both have influence on fuel consumption. An associated development process is being elaborated that enables a fast adaptation of the TMF to new architectures and systems. This will be illustrated by means of a bleedless thermal management architecture.
Technical Paper

Model-Based Energy Management Functions for Aircraft Electrical Systems

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.
Technical Paper

Exploitation Strategies of Cabin and Galley Thermal Dynamics

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.