Publications

Aerostructural optimization traditionally uses a single or small number of cruise conditions to estimate the mission fuel burn objective function. In reality, a mission includes other flight segments contributing to fuel burn, such as climbing and descent. We aim to quantify how much performance is sacrificed by optimizing the design for a fuel burn approximation that ignores these other flight segments and flight conditions. To do this, we compare traditional approaches to mission-based optimization, which uses an accurate fuel burn objective computed by numerically integrating fuel flow across the mission profile. We find that mission-based optimization offers only marginal benefits over traditional single-point and multipoint approaches for aerostructural optimization of a narrowbody aircraft—only 1–2% in the most extreme cases. Thus, the traditional aerostructural optimization is acceptable, especially in cases where most fuel is burned during cruise. For the cases where climb fuel burn is significant, we introduce a simple change to traditional fuel burn approximation methods that allows the optimizer to find nearly all the fuel burn reduction of mission-based optimization but at the computational cost of multipoint optimization.