The computer simulation shows how the wings deform during a flight manoeuvre. It is a research aircraft configuration. The researchers were able to design a long-range aircraft using their simulation methods, validated with flight test data.
Credit: DLR (CC-BY 3.0).
The wings of the A320 ATRA were covered with a special foil to optically measure deformations during flight.
The stereo camera system inside the ATRA was directed towards the wings. The cameras measured wing deformation during flight manoeuvres.
The wings flex, the fuel tank contents slosh, the loading of passengers and cargo varies from flight to flight – aircraft are highly complex systems influenced by numerous variables. What are the implications if some of them change? Or all of them? From now on, the answers are only a few mouse clicks away. Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have developed a basis for the complete digital development and description of an aircraft in the Virtual Aircraft Technology Integration Platform (VicToria) project.
Thirteen DLR institutes with more than 160 researchers were involved in the VicToria project."We are now able to carry out virtual flight tests that can be matched in detail with real flight tests," explains Stefan Görtz, the VicToria Project Manager from the DLR Institute of Aerodynamics and Flow Technology in Braunschweig. "This means we can build a virtual model of an aircraft or helicopter with all its characteristics." These can be used, for example, to improve passenger comfort during gusts or flight manoeuvres. But it extends far beyond that – DLR can virtually design, test and fly aircraft that do not yet exist. This includes the possibility of evaluating new technologies to make flying more environmentally friendly and cost effective.
Aerodynamics, aeroelasticity, load analysis, flight dynamics and structure all in one
"We are making steady progress towards the digitalisation of aeronautics," says Görtz. DLR has brought together all the relevant disciplines – aerodynamics, aeroelasticity, load analysis, flight dynamics and structure – in the VicToria project, which has run for four years with an expenditure of 36 million euros. The virtual tests with a 'digital twin' of the DLR Advanced Technology Research Aircraft (ATRA) were verified using data from wind tunnel tests and actual flights. This allowed the simulation models to be constantly updated. For example, a stereo camera system measured the deformation of the wings during various flight manoeuvres.
The idea of designing a purely digital process for developing and certifying an aircraft was born almost 50 years ago. At the time, it was believed that real flight testing could soon be dispensed with; this was a mistake. Not only was the performance of computers limited at that time, but complex airflows, for example, could not yet be represented correctly. This is now possible with the help of numerical simulation. In the meantime, researchers believe that the development process will increasingly rely on simulations and that, in future, first flights will take place virtually in a computer. This will enable financial and economic risks to be mitigated. Real-life flight experiments will then be conducted for verification and confirmation. Future certification of aircraft and helicopters using computer-based simulations is now getting closer. DLR is also working on corresponding simulation tools in the Simulation Based Certification (SimBaCon) project.
An in-depth interview with Stefan Görtz on the digitalisation of aeronautics was published in DLRmagazine 167.