DLR project Digital-X: towards virtual aircraft design and flight testing based on high-fidelity methods

Abstract

Numerical simulation is already an important cornerstone for aircraft design, although the application of highly accurate methods is mainly limited to the design point. To meet future technical, economic and social challenges in aviation, it is essential to simulate a real aircraft at an early stage, including all multidisciplinary interactions covering the entire flight envelope, and to have the ability to provide data with guaranteed accuracy required for development and certification. However, despite the considerable progress made there are still significant obstacles to be overcome in the development of numerical methods, physical modeling, and the integration of different aircraft disciplines for multidisciplinary analysis and optimization of realistic aircraft configurations. At DLR, these challenges are being addressed in the framework of the multidisciplinary project Digital-X (4/ 2012-12/2015). This paper provides an overview of the project objectives and presents first results on enhanced disciplinary methods in aerodynamics and structural analysis, the development of efficient reduced order methods for load analysis, the development of a multidisciplinary optimization process based on a multi-level/variable-fidelity approach, as well as the development and application of multidisciplinary methods for the analysis of maneuver loads.

TiGL: An Open Source Computational Geometry Library for Parametric Aircraft Design

“…With the help of TiGL, slight modifications of aircraft geometries can be created in an automated workflow. CPACS and TiGL are currently being developed and constantly extentended in research projects related to MDO [12][13][14]. Some ideas to increase the optimization capabilities in the future are…”

“…M do 11 Compute g l (v) by reparametrizingg l (ṽ) using m control points analogous to the profiles. 12 Compute profile skinning surface S f (u, v) with interpolation parameters {v k } according to (15). 13 Compute guide skinning surface S g (u, v) with interpolation parameters {u l } according to (16).…”

PANDORA - A python based framework for modelling and structural sizing of transport aircraft

“…The loadcases stored in the CPACS file are generated using a condensated dynamic massstiffness model of the aircraft and simulating different flight maneuvers and gust loads. Therefore different tools at DLR like MONA exist to create the dynamical structural model or Varloads to evaluate loadcases [11].…”

Virtual flight testing of a controller for gust load alleviation using FMI for cosimulation

“…These have no closed form analytical solution and can only be solved by employing numerical methods from Computational Fluid Dynamics (CFD). The Python -based software framework FlowSimulator (Meinel and Einarsson, 2010) and CFD solver TAU (Schwamborn et al, 2006) were developed and utilized in the Digital-X project for multidisciplinary simulation of transport aircraft with aerodynamics calculated by CFD (Kroll et al, 2016). A Modelica -based flight control system with added gust load alleviation functionality had to be integrated in the FlowSimulator setup to conduct the virtual flight tests by means of cosimulation using the FMI 2.0 -standard (Mod, 2014).…”