Integrated analysis and design environment for a climate compatible air transportation system

Aviation affects the Earth’s atmosphere and radiative balance through the emission of greenhouse gases, greenhouse gas precursors, aerosols, contrails and induced cirrus cloudiness. The resulting climate impact is a response of the complex interactions between the amount and type of emitted constituents, their geographical position, altitude and time of emission as well as the actual weather and climate situation. In 2005 aviation accounted for 3.5 % of the global anthropogenic radiative forcing (excluding the impact of contrail cirrus clouds). As the global air traffic is predicted to grow approx. 5% per year, the development of a climate compatible air transport system is of increasing importance for society and science. To achieve this goal, different technological and operational options can be applied to reduce the climate impact by air travel. The range of possibilities is wide, including new propulsion concepts such as open rotors or intercooler recuperative engine cycles, improved combustion chambers for low NOX and soot, novel aircraft configurations such as Blended Wing Bodies, innovative subsystem architectures for minimal engine cycle disturbance through secondary power off take and operational procedures such as multi-step operations and changed cruise altitudes for contrail avoidance. In order to provide a solid basis for decision and policy makers, the remaining uncertainties in climate modeling have to be reduced and the different options and their interrelations have to be assessed in a reliable way. To catch all relevant effects of the coupled disciplines, sophisticated numerical models for climate response, mission calculation, propulsion, aircraft subsystems and overall aircraft design are combined to an integrated simulation and assessment chain. In addition, further efforts are made to reduce remaining uncertainties in modeling emissions and their corresponding climate impact. This complex and multidisciplinary task further requires the contribution of experts from the included areas to ensure a secure evaluation of the obtained results. Here we present such an integrated approach as it is applied within the DLR project Climate compatible Air Transport System (CATS)