S OF PAPERS, 86th Annual Meeting of the Virginia Academy of Science, May 20-23, 2008, Hampton University, Hampton VA Aeronautical and Aerospace Sciences A DESIGN CONCEPT FOR ALLEVIATING SOME SIZE CONSTRANTS FOR LARGE AIRCRAFT. M. Leroy Spearman, NASA-Langley Research Center, Hampton, VA 23681. The basic wing-body-tail arrangement of conventional transport aircraft generally consists of a centra...

The application of active flow control on a vertical tail of a typical twin engine aircraft was investigated. Sweeping jets installed into the rudder surface were used and their effect was assessed by force measurements, flow visualization and local pressure distributions. The airfoil forming the tail is a NACA 0012 with a rudder using 35% of its chord. The tests were carried out at the Lucas W...

This paper explores infrared quantum effects in the de Sitter space. The notion of ”eternal manifolds” is introduced and it is shown that in most cases the de Sitter space doesn’t belong to this class. It is unstable under small perturbations which may cause a breakdown of the de Sitter symmetry. The de Sitter string sigma model is discussed. It is argued that the gauge theory at the complex co...

This paper proposes novel Fuel Cell Auxiliary Power Unit (FCAPU) for J150+ aircraft application. The primary version of APU in J150+ aircraft is a gas turbine Auxiliary Power Unit (APU) which is based on gas turbine jet engine but in the suggested FCAPU, the generated electrical power is achieved from chemical energy with higher efficiency. The Solid Oxide Fuel Cell (SOFC) technology is used to...

A ircraft enhancement is widely used on the east coast of Australia for VHF and UHF contacts in the 240 to 480 mile (400 to 800 km) range. Typically, for a few minutes it produces enhanced signals that are 20 to 30 dB stronger than would be expected, based on radar reflection or tropo scatter. The key difference between aircraft enhancement and normal radar reflections is that the aircraft must...

The generalized connections of the de Sitter algebra so(d, 1) and anti-de Sitter algebra so(d − 1, 2), which are differential forms of arbitrary degree with values in any irreducible (spin)-tensor representation of the (anti)-de Sitter algebra, are studied. It is shown that arbitrary-spin gauge field in (anti)-de Sitter space, massless or partially-massless, can be described by a single connect...

With the advantages of long-range flight and high payload capacity, large fixed-wing UAVs are often used in anti-terrorism missions, disaster surveillance, emergency supply delivery. In existing research, there is little research on 3D model design V-tail UAV environment modeling. The study focuses designing a comprehensive simulation using Gazebo ROS, referencing UAVs, to aircraft, incorporati...

Every de Sitter vacuum can transition to every other de Sitter vacuum despite any obstacle, despite intervening anti-de Sitter sinks, despite not being connected by an instanton. Eternal inflation populates the whole landscape.

dS 4,1 spacetime, projective embedded coordinates and associated isometry groups Abstract This work is intended to investigate the de Sitter metric and to give another description of the hyperbolical embedding standard formalism of the de Sitter space-time in a pseudoeu-clidean space-time E 4,1. Classical results in this mathematical formulation are reviewed in a more general setting together w...

We propose that the state represented by the Nariai black hole inside de Sitter space is the ground state of the de Sitter gravity, while the pure de Sitter space is the maximal energy state. With this point of view, we investigate thermodynamics of de Sitter space, we find that if there is a dual field theory, this theory can not be a CFT in a fixed dimension. Near the Nariai limit, we propose...