Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. a...

Stage separation is a critical technical issue for developing two-stage-to-orbit (TSTO) launch systems with widebody carrier aircraft that use air-breathing propulsion and launch vehicle stages that use rocket propulsion. During conceptual design phases, this issue can be addressed with a combination of engineering methods, computational fluid dynamics simulations, and trajectory analysis of th...

Flight control of hypersonic vehicles is challenging because of the wide range of operating conditions encountered and certain aspects unique to high speed flight. A particular safety concern in hypersonic flight is the risk of an inlet unstart, which not only produces a significant decrease in thrust but also results in a change to the aerodynamics and thus can lead to the loss of the vehicle....

An advanced wind tunnel has been introduced as a facility for road vehicle development at the Kindai University (KURING). In this paper, the features of this wind tunnel, which can generate arbitrary patterns of time-varying wind velocities, are first described. There are four representative airflow patterns: steady wind with constant velocity, pulsating wind with oscillating velocity, gusts of...

The difficulty of accurately modeling the aerodynamics heading angle unmanned aerial vehicles is well known. Furthermore, it difficult to control an vehicle (UAV) with a model-based method under influence wind disturbances. To address this problem, novel model-free strategy proposed. First, self-organizing type-2 fuzzy brain emotional learning network model used estimate PPD (pseudo partial der...

Unsteady helicopter rotor aerodynamics are complicated. This paper reviews some of the fundamentals and newer developments of unsteady helicopter aerodynamics. Rotor flow is beautiful and complex. Visualizing rotor flow allows for an appreciation of the following theories and solution attempts as well as nature’s complexities. The flow through a helicopter rotor with forward motion is shown in ...

In this study the centre manifold is applied for reduction and limit cycle calculation of a highly nonlinear structural aeroelastic wing. The limit cycle is arisen from structural nonlinearity due to the large deflection of the wing. Results obtained by different orders of centre manifolds are compared with those obtained by time marching method (fourth-order Runge-Kutta method). These comparis...

A methodology for improving attitude stability and control for low-speed and hovering air vehicle is under development. In addition to aerodynamically induced control forces such as vector thrusting, the new approach exploits the use of bias momenta and torque actuators, similar to a class of spacecraft system, for its guidance and control needs. This approach will be validated on a free-flying...

sonic Unsteady Lifting Surfaces," AIAA Journal, Vol. 22, No. 2, 1984, pp. 179-186. Tewari, A., "Nonplanar Doublet-Point Method in Supersonic Three-Dimensional, Unsteady Aerodynamics," M.S. Thesis, Univ. of Missouri-Rolla, Rolla, MO, 1988. Tewari, A., "New Acceleration Potential Method for Supersonic Unsteady Aerodynamics of Lifting Surfaces, Further Extension of the Nonplanar Doublet Point Meth...

Abstract The success of drone missions is incumbent on an accurate determination the pose and velocity, which are collectively estimated by fusing inertial measurement unit global navigation satellite system (GNSS) measurements. However, during a GNSS outage, long-term accuracy these estimations far from allowing practical use. In contrast, vehicle dynamic model (VDM)-based has demonst...