Development of a Distributed Approach to System Level Uncertainty Quantification (Project 48)

As part of its tool development effort, the FAA Office of Energy and the Environment leads research analyses of policy outcomes to uncertainties in input parameters and assumptions of different tools. In Project 48 we are creating a new aircraft conceptual design capability in the FAA tools suite, through Transport Aircraft System OPTimization (TASOpt), and developing an approach to perform a system-level quantification of uncertainty. This system-level assessment will quantify how input uncertainties propagate through a system comprising multiple modeling components. Specifically, we are interested in quantifying how uncertainties at the aircraft design level propagate through the Environmental Tool Suite and contribute to uncertainty in overall policy outcomes. We also wish to conduct sensitivity analyses—identifying which input factors and assumptions contribute most to uncertainty in tool outputs.

To expand the aircraft conceptual design capability of the FAA Environmental Tool Suite, we have established a process and codes for coupling TASOpt with Aviation Environment Design Tool (AEDT) Version 2a for fuel burn calculations. This coupling enables fleet-wide assessment of advanced technology aircraft configurations with respect to fuel burn changes and the associated environmental impacts. Our work is now expanding TASOpt’s capabilities through development of an elastic beam model that includes bending and torsion, a vortex-lattice model for aerodynamics, and an improved engine module. We will define and validate TASOpt models for a Single Twin Aisle aircraft, such as a Boeing 767, and a Large Quad aircraft, such as a Boeing 747. The improved TASOpt modeling and the development of the two TASOpt aircraft models will expand applicability of TASOpt to other aircraft classes and engine types, thus providing value for the future use of TASOpt as part of the FAA tools suite.

The system-level uncertainty quantification work is developing a new distributed approach that lets the analysis be performed locally on individual models, followed by a synthesis step to resolve couplings among models. In this way, we avoid the need to tightly integrate the various modeling components. The mathematical approach draws on concepts and algorithms from multidisciplinary analysis and optimization, density estimation, and sequential Monte Carlo methods. We are implementing this new approach on a toolset consisting of TASOpt and AEDT Version 2a.

Anticipated outcome: TASOpt v2, with extensions that expand the Toolsuite capabilities in evaluating technology scenarios and assessing the impact of future aircraft designs. New methodology for a distributed approach to system-level quantification of uncertainty. Uncertainty analysis and sensitivity analysis of the coupled system comprising TASOPT and AEDT Version 2a.
Anticipated outcomes

TASOpt v2, with extensions that expand the Tool Suite capabilities in evaluating technology scenarios and assessing the impact of future aircraft designs. New methodology for a distributed approach to system-level quantification of uncertainty. Uncertainty analysis and sensitivity analysis of the coupled system comprising TASOPT and AEDT Version 2a.