This paper discusses the influence of aerodynamic drag torque on the dynamics of a satellite in a very low altitude orbit. The larger atmospheric density in low altitude earth orbits results in significant aerodynamic drag torques acting on the satellite. With a conventional satellite design this may result in instability. This paper shows how the instability can be avoided, and how the aerodyn...

this work aimed to prepare a nanoemulsion preparation containing budesonide and assess its aerodynamic behavior in comparison with suspension of budesonide. in-vitro aerodynamic performance of the corresponding micellar solution (ie. nanoemulsion preparation without oil) was investigated too. nanoemulsions of almond oil containing budesonide, as a hydrophobic model drug molecule, were prepared ...

NASA’s Hyper-X Research Vehicle will provide a unique opportunity to obtain data on an operational airframe integrated scramjet propulsion system at true flight conditions. The airframe integrated nature of the scramjet engine with the Hyper-X vehicle results in a strong coupling effect between the propulsion system operation and the airframe’s basic aerodynamic characteristics. Comments on gen...

Noise generated by turbulent boundary layers near the trailing edge of lifting surfaces continues to pose a challenge for many applications. Much of the previous work on this topic has focused on development of accurate computational methods for the prediction of trailing edge noise. For instance, aeroacoustic calculations of the flow over an airfoil using large-eddy simulation (LES) and aeroac...

Claire Tomlin, John Lygeros, and Shankar Sastry Department of Electrical Engineering and Computer Sciences University of California, Berkeley, CA 94720-1772 clairet, lygeros, [email protected] Abstract This paper presents the application of controller synthesis for hybrid systems to aerodynamic envelope protection and safe switching between ight modes. Each ight mode, which describes a c...

The NASA F-15 Intelligent Flight Control System project team has developed a series of flight control concepts designed to demonstrate the benefits of a neural network-based adaptive controller. The objective of the team is to develop and flight-test control systems that use neural network technology to optimize the performance of the aircraft under nominal conditions as well as stabilize the a...

This study deals with the use of optimization algorithms to determine efficient parameters of flow control devices. To improve the performance of systems characterized by detached flows and vortex shedding, the use of flow control devices such as oscillatory jets, are intensively studied, using numerical as well as experimental methods. However, the determination of efficient control parameters...

A robust, large-force, large-deflection micro balloon actuator for aerodynamic (maneuvering) control of transonic aircraft has been developed. Using a novel process, high yield linear arrays of silicone balloons on a robust silicon substrate have been fabricated that can deflect vertically in excess of one 111111. Balloon actuators have been tested under cyclic conditions to assess reliability....

Civil unmanned aircraft will need to meet stringent safety standards before they are certified to operate in the national airspace of the United States. Reliability is a key requirement for certification. Most current civil unmanned aircraft are not reliable because of the presence of single points-of-failure and the use of low-reliability components. For example: Many fixed-wing unmanned aircr...

Smart Morphable Surfaces enable switchable and tunable aerodynamic drag reduction of bluff bodies. Their topography, resembling the morphology of golf balls, can be custom-generated through a wrinkling instability on a curved surface. Pneumatic actuation of these patterns results in the control of the drag coefficient of spherical samples by up to a factor of two, over a range of flow conditions.