Estimates of global aviation fuel burn and emissions are currently nearly 10years out of date. Here, the development of the Aircraft Performance Model Implementation (APMI) software which is used to update global commercial aviation fuel burn and emissions estimates is described. The results from APMI are compared with published estimates obtained using the US Federal Aviation Administration’s System for Assessing Aviation’s Global Emissions (SAGE) for the year 2006. The number of global departures modelled with the APMI software is 8% lower compared with SAGE and reflects the difference between their commercial air traffic statistics data sources. The mission fuel burn, CO2 and H2O estimates from APMI are approximately 20% lower than those predicted by SAGE for 2006 while the estimate for the total global aircraft SOx emissions is approximately 40% lower. The estimates for the emissions of CO, HC and NOx are 10%, 140% and 30% higher than those predicted by SAGE respectively. The reasons for these differences are discussed in detail
1 December 2015 in Journal of Guidance, Control, and Dynamics
In this paper, the influence of the flight control system over the offnominal behavior of a remotely operated air vehicle is evaluated. Of particular interest is the departure/upset characteristics of the closed-loop system near and beyond stall. The study vehicle is the NASA Generic Transport Model, and both fixed-gain and gain-scheduled versions of a linear quadratic regulator controller with proportional and integral components are evaluated. Bifurcation analysis is used to characterize spiral and spin behavior of the aircraft in closed-loop form and yields an understanding of the underlying vehicle dynamics outside the standard flight envelope. The use of a “gain parameter” to scale the controller gains provides information on the sensitivity of stability to gain variation, along with tracking how the controller modifies the open-loop steady states. Hence, this provides a means of assessing the effectiveness of the controller and evaluating the upset tendencies of the aircraft.
A new five-degree-of-freedom rig for the dynamic wind-tunnel testing of aircraft models has been developed. The maneuver rig enables a large set of conventional and more-extreme aircraft maneuvers to be performed in the controlled environment of a wind tunnel, allowing direct physical simulation of in-flight maneuvers and the identification of aerodynamic models from aircraft-model time histories. A mathematical model of the rig has been developed for numerical simulation and identification purposes. The development of a quasi-steady aerodynamic model of the longitudinal motion for a subscale test aircraft is presented to illustrate rig capabilities. The longitudinal modes of motion are excited by a remotely controlled aircraft-model stabilator and dynamic-rig aerodynamic compensator deflections. Two rig configurations are considered: aircraft-model pitch only and aircraft-model pitch with heave, which is implemented via rig-pitch motion. The aircraft-model tail and wing in the mathematical model are cons...