Vehicle automation requires new onboard sensors, communication equipment, and/or data processing units, and may encourage modifications to existing components (such as the steering wheel). These changes impact vehicle’s mass, auxiliary load, coefficient of drag, frontal area, which then change vehicle performance. This paper uses powertrain simulation model FASTSim quantify autonomy-related des...

Conventional quaternion based methods have been extensively employed for spacecraft attitude control where the aerodynamic forces can be neglected. In the presence of aerodynamic forces, the flight attitude control is more complicated due to aerodynamic moments and inertia uncertainties. In this paper, a robust nero-adaptive quat...

Widespread damage to roofs in hurricanes and other high wind events has highlighted the need for improving the wind performance of roofs, including both new construction and retrofit on existing buildings. Effective and economical methods to mitigate wind effects on roof components are sought to reduce accumulated losses from frequently recurring lowand moderate-intensity events. An experimenta...

Using force measurements and flow visualization in a water tunnel, we consider motions of a flat plate with square edges, free to pivot about its leading edge, between incidence angle limits of ±45°. The plate’s leading edge undergoes a prescribed sinusoidal motion, either of rectilinear translation, or of pivoting or waving about a fixed point 0.5 chords away from one of the plate’s wingtips. ...

Insects are a prime source of inspiration towards the development of small-scale, engineered, flapping wing flight systems. To help interpret the possible energy transformation strategies observed in Diptera as inspiration for mechanical flapping flight systems, we revisit the perspective of the dipteran wing motor as a bistable click mechanism and take a new, and more flexible, outlook to the ...

The purpose of the current test program is to produce a new dataset with sufficient documentation to be useful for correlation, development, and refinement of aerodynamic models at high thrust. An aerodynamic limits test was conducted in the 7by 10-Foot Wind Tunnel at Ames Research Center. The objectives of the test were to measure the performance and control loads of the rotor in nominal thrus...

Insect wings usually are flexible and deform significantly under the combined inertial and aerodynamic load. To study the effect of wing flexibility on both lift and thrust production in forward flight, a two-dimensional numerical simulation is employed to compute the fluid–structure interaction of an elastic wing section translating in an inclined stroke plane while pitching around its leading...

A fluid-structure analysis framework which couples Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) is constructed to study the aero-mechanics of a helicopter rotor system under maneuvering flight conditions. The CFD approach consists of the solution of Unsteady Reynolds Average Navier Stokes (URANS) equations for the near-field of the rotor coupled with the dynami...