ALEF · Aerodynamic loads estimation at extremes of the flight envelope

ALEF's objective is to enable the European aeronautical industry to create complete aerodynamic models of their aircraft based on numerical simulation approaches within the respective development processes. I.e. ALEF will kick-off a paradigm shift from greater confidence in experimentally measured loads data to greater confidence in computational results. Beyond the scope of ALEF this paradigm shift will essentially influence the overall aerodynamic development process. The objective has three aspects: 1. Comprehensiveness refers to the ability to predict aerodynamic forces, moments and their derivatives in time for any point of the flight regime. It is addressed by two complementary approaches: A high fidelity CFD based approach serves short-term impact. Long-term improvements are delivered by incorporation of simulation tools of different fidelity. 2. Quality refers to the accuracy and physical correctness of each flow simulation result used for aero data prediction as well as to a high coherence of aero data integrated over the complete flight envelope from tools of varying fidelity. It is improved by considering the impact of physical modelling as well as novel quality control means to achieve a highly coherent data space representation. 3. Efficiency refers to the necessity to compute the entire aero data space within time frames dictated by industrial design processes at given costs. It is tackled by means of surrogate models for both steady and unsteady flows. Also planning techniques for efficient simulation campaigns are addressed. The ultimate scope of using simulation tools in aero data generation is to cover all flight conditions and configurations by means of a numerical toolbox. This would ensure an up-to-date and fast estimation of most recent statuses of aircraft with every data consistent. ALEF will essentially contribute to a 70% wind tunnel testing cost reduction by 2020, which will cut the aerodynamic development effort by about 40%.