Finmeccanica (United Kingdom)

<div class="section abstract"><div class="htmlview paragraph">This paper presents the activities foreseen on the Leonardo Aircraft Division EIS (Entry In Service) 2020 derivative aircraft performed in the frame of the FP7 European research project TOICA (Thermal Overall Integrated Concept of Aircraft). On board air systems for conventional aircraft are fed by the bleed off-take which penalizes the amount of power available to the turbine of jet or turboprop engines. In order to minimize such operating penalties and optimize the energy efficiency of the overall aircraft, it is of major interest to support trade-offs at aircraft level including aircraft systems as early as possible in the development cycle. The study presents the Virtual Integrated Aircraft methodology and associated simulation activities relying on the system simulation platform LMS Imagine.Lab. This methodology is also relying on concept of flexible model and pyramid of models developed in the context of TOICA. Several aircraft configurations and ECS (Environmental Control System) packs architectures are studied and the different steps of the methodology are shown up to the trade between different aircraft configurations. From the very beginning of the design cycle, the requirements and the objectives for the air conditioning system are complemented with thermal requirements by performing thermal evaluations for the design points covering the aircraft operating conditions. Pre-sizing of every ECS pack component is achieved. Then, the resulting ECS packs numerical models are integrated with the engine bleed air system and the thermal model of the structure including the different heat loads, passengers and electronic equipment mainly. The integration is finally assessed over complete flight missions allowing to validate not only the steady state ECS performance, but also the transient pull up and pull down conditions as well as the overall engine bleed off-take and energy balance.</div></div>

Geolocation is the process of calculating a target position based on bearing and range relative to the known location of the observer. A high performance thermal imager with integrated geolocation functions is a powerful long range targeting device. Firefly is a software defined camera core incorporating a system-on-a-chip processor running the Android TM operating system. The processor has a range of industry standard serial interfaces which were used to interface to peripheral devices including a laser rangefinder and a digital magnetic compass. The core has built in Global Positioning System (GPS) which provides the third variable required for geolocation. The graphical capability of Firefly allowed flexibility in the design of the man-machine interface (MMI), so the finished system can give access to extensive functionality without appearing cumbersome or over-complicated to the user. This paper covers both the hardware and software design of the system, including how the camera core influenced the selection of peripheral hardware, and the MMI design process which incorporated user feedback at various stages.

This paper presents a comprehensive study on the reliability of QFN components for aerospace applications, particularly the impact of conformal coatings on the reliability of such QFN assemblies was investigated. Both experimental and computational modeling techniques are discussed. In the experiments, several types of plastic and ceramic QFNs assemblies were subjected to accelerated thermal cycling test, the daisy chains were monitored continuously during the test and the solder joints failures were recorded automatically with the cycle number at time of failure. Finite element models were developed for each type QFN assembly and the inelastic strain energy density was used as an indicator of the damage induced in solder joints under the applied thermal cycling load. Using simulation predicted damage together with the experimentally measured lifetime has provided the opportunity to develop a new physics-of-failure life prediction model for the second level solder interconnects in these QFN packages. The impact of conformal coatings on the reliability of QFN assemblies was revealed through comparing the results of non-coated assemblies with conformal coating coated assemblies. It was found that using coatings did not always increase the damage in the solder joint, the magnitude of the impact is dependent on the package size and the coating properties. Parametric analysis reveals that parameters such as die area and CTE of molding compound have less impact on the solder joint reliability when conformal coating is used.