Centrifugal compressor stages using vaneless diffusers are known to have a wide operating range. However, when operated outside of this range, instabilities have been reported to commonly develop in the impeller (rotor) or diffuser or both. The unsteady flow phenomena are believed to start from a localized flow separation (stall) that frequently will orbit within the stage at sub-harmonic rotational speeds (rotating stall). If not damped sufficiently the stall cells will eventually develop into more hazardous self-excited pressure oscillations within the entire compressor stage leading to surge phenomena that can induce high aero-elastic loads on the rotor itself leading to premature aging (fatigue) or ultimate failure of the stage. Predicting of the onset of the instabilities is a prerequisite to maintain compressor operating within safe operating margins. Nonetheless the physical understanding and associated modeling of the stall and surge inception is rather limited and mostly restricted to cause-and-effect investigations. With improved computational models being available nowadays more in-depth investigations of the underlying flow physics have become possible, but relies on high quality experimental data for validation. Following the statement of work put forth in the call for proposal, the first objective of the proposed project is to determine a surge inception scenario for a given academic as well as industrial reference case of centrifugal compressor using vaneless diffuser. Within the proposed project the off-design behavior of each compressor configuration will be investigated both numerically and experimentally, involving time-resolved Kulite array and PIV measurements. Based on this data and on existing theoretical analysis procedures, the second major effort of the present study is devoted to define low-order methodologies that ideally predict the onset of instabilities.

Single European Sky – the vision is clearly described in the ATM Masterplan. Reaching the goals for the European Airspace is only possible with focused technical developments on European level. The air traffic controller is the main player in the traffic management at tactical level. This project aims at providing the air traffic controller with more automated tools, thus freeing capacity for situations where human intervention is crucial. This provides even safer service for an increasing amount of traffic and with lower costs, as required by airspace users. This project is a part of the SESAR programme and addresses separation management. It will not only improve current conflict detection tools, but also develop new tools aiding the air traffic controller with resolution advisory and monitoring of flight trajectory. The project also addresses new ways of working together. Air traffic controllers traditionally work in pairs and in specific airspace. Could we change this to multi-planner setup, sector less airspace and seamless cross-border operations? Our project will ensure the research is developed to a stage where it can be used in operational air traffic management systems in Europe. This ensures that anyone can fly safer, cheaper and quicker in Europe in 10 years. Another really important issue is the integration of “Remotely Piloted Aircraft Systems” – drones. Drones are new to European Air Traffic Management, and it is urgent to address concepts and technological developments needed to handle this kind of traffic safely. The companies involved in this project are the only ones that can deliver this kind of result. Not on their own – but as the unique cooperation between air navigation service providers and air and ground industry. The capabilities to provide sustainable results usable throughout Europe by fast-time, real-time simulations and live trials ensures that developed prototypes are working in the context of future traffic and ATM systems.

This document describes the research to be undertaken by the project OptiFrame – “An Optimization Framework for Trajectory Based Operations” - funded by the EU call “SESAR 2020 Exploratory Research: First Call for Research Project”, research topic “Trajectory Based Operations (TBO)” (ER-09-2015), within the area “ATM Applications-Oriented Research”. The project consortium comprises University of Lancaster (Project Coordinator), the Consorzio Futuro in Ricerca, Eurocontrol and the Stichting Nationaal Lucht- en Ruimtevaartlaboratorium (NLR). OptiFrame is motivated by the need of studying a number of fundamental questions related to TBO, a key element of future ATM operating concepts. The main objective of this research proposal is the application of principles of mathematical modelling and optimization to optimally configure and assess the performance of the TBO concept. This will allow to verify the viability of the TBO concept, to identify the major issues that need to be addressed, and determine whether, under which conditions, and to what extent, the objectives of flexibility of airspace users and predictability of the ATM system, can be achieved. The core activity and focus of this proposal is the development of a framework, which consists of mathematical models and optimization algorithms, “to support the ATFCM decision making process” by suggesting optimal TBO solutions. The framework will be applied in real world instances, and it will be used to perform a wide array of analyses. We will use OptiFrame as a tool to: i) investigate several of the issues and questions arising for the exploitation and deployment of the TBO concept, ii) fully understand the benefits and limitations of the TBO approach, and iii) study the trade-off between different contrasting KPIs relevant for the TBO concept.

The EC Flight Path 2050 vision aims to achieve the highest levels of safety to ensure that passengers and freight as well as the air transport system and its infrastructure are protected. However, trends in safety performance over the last decade indicate that the ACARE Vision 2020 safety goal of an 80% reduction of the accident rate is not being achieved. A stronger focus on safety is required. There is a need to start a Joint Research Programme (JRP) on Aviation Safety, aiming for Coordinated Safety Research as well as Safety Research Coordination. The proposed JRP Safety, established under coordination of EREA, is built on European safety priorities, around four main themes with each theme consisting of a small set of projects. Theme 1 (New solutions for today’s accidents) aims for breakthrough research with the purpose of enabling a direct, specific, significant risk reduction in the medium term. Theme 2 (Strengthening the capability to manage risk) conducts research on processes and technologies to enable the aviation system actors to achieve near-total control over the safety risk in the air transport system. Theme 3 (Building ultra-resilient systems and operators) conducts research on the improvement of Systems and the Human Operator with the specific aim to improve safety performance under unanticipated circumstances. Theme 4 (Building ultra-resilient vehicles), aims at reducing the effect of external hazards on the aerial vehicle integrity, as well as improving the safety of the cabin environment. To really connect and drive complementary Safety R&D (by EREA) to safety priorities as put forward in the EASA European Aviation Safety plan (EASp) and the EC ACARE Strategic Research and Innovation (RIA)Agenda, Safety Research Coordination activities are proposed. Focus on key priorities that impact the safety level most will significantly increase the leverage effect of the complementary safety Research and Innovation actions planned and performed by EREA.