An impact angle constrained fuzzy adaptive fault tolerant integrated guidance and control method for Ski-to-Turn (STT) missiles subject to unsteady aerodynamics multiple disturbances is proposed. Unsteady appears when flight vehicles are in a transonic state or confronted with unstable airflow. Meanwhile, actuator failures multisource model uncertainties introduced. However, the boundaries of t...

Unsteady flow models of wings and airfoils have been studied to understand the aerodynamic performance of natural flyers and provide improved maneuverability for micro aerial vehicles (MAVs). Vortex methods have been extensively applied to reduce the dimensionality of these aerodynamic models, based on the proper estimation of the distribution and evolution of the vortices in the wake. In such ...

Traditionally, the estimation of wind induced buffeting response and analysis of flutter instability have been conducted in the frequency domain utilizing linear approaches. These approaches are limited to linear structures in which nonlinearities in aerodynamic forces are ignored. In this study, a time domain analysis framework for predicting the flutter and buffeting responses of bridges unde...

Recent developments of the aerodynamics models for the comprehensive analysis CAMRAD II are described, particularly the unsteady aerodynamic models and dynamic stall models, and the free wake geometry calculation. Three models for the unsteady aerodynamic loads in attached flow are implemented: from incompressible thin-airfoil theory, from ONERA EDLIN, and from Leishman-Beddoes. Five dynamic st...

A finite element flow solver was employed to compute unsteady flow past a three-dimensional Drosophila wing undergoing flapping motion. The computed thrust and drag forces agreed well with results from a previous experimental study. A grid-refinement study was performed to validate the computational results, and a grid-independent solution was achieved. The effect of phasing between the transla...

Low Reynolds number aerodynamics is important for various applications including micro-aerial vehicles, sailplanes, leading edge control devices, high-altitude unmanned vehicles, wind turbines and propellers. These flows are generally characterized by the presence of laminar separation bubbles. These bubbles are generally unsteady and have a significant effect on the overall resulting aerodynam...

■ Abstract “What force does an insect wing generate?” Finding answers to this enduring question is an essential step toward our understanding of interactions of moving objects with fluids that enable most living species such as insects, birds, and fish to travel efficiently and us to follow similar suit with sails, oars, and airfoils. We give a brief history of research in insect flight and dis...

An output-based dynamic order re nement strategy is presented for unsteady simulations using the discontinuous Galerkin nite element method in space and time. A discrete unsteady adjoint solution provides scalar output error estimates and drives adaptive re nement of the space-time mesh. Space-time anisotropy is measured using projection of the adjoint onto semi-re ned spaces and is used to all...