Icing is widely recognized as one of the most serious weather hazards to aircraft operations. Aircraft icing occurs when small, super-cooled, airborne water droplets, which make up clouds and fog, freeze upon impact with a surface, which results in the formation of ice (Mason 1971). The freezing can be complete or partial, depending on how rapidly the latent heat of fusion can be released into ...

The unsteady load response of an airfoil encountering a gust is often modeled using analytical transfer functions, which assume idealized behavior both the flow and airfoil. One such function Sears function, models pure transverse interacting with flat-plate at zero mean incidence. was extended by Goldstein Atassi (“A Complete Second-Order Theory for Unsteady Flow About Airfoil due to Periodic ...

an elliptical tank cross-section is formulated to explore and optimization method, based on a real-coded genetic algorithm to enhance the roll stability limit of a tank vehicle. a shape genetic algorithm optimization problem is applied to minimize the overturning moment imposed on the vehicle due to c.g. height of the liquid load, and lateral acceleration and cargo load shift . the minimization...

In a previous work, a mechanism was presented by which baryon asymmetry can be generated during inflation from elliptically polarized gravitons. Nonetheless, the mechanism only generated a realistic baryon asymmetry under special circumstances which requires an enhancement of the lepton number from an unspecified GUT. In this note we provide a stringy embedding of this mechanism through the Gre...

The method of matched asymptotic expansions is used to solve the problem of flow over a thin airfoil possessing a trailing-edge appendage, which may be of a general character, but is confined to a region of small size compared to the airfoil's chord. A feature of this asymptotic solution is effective de-coupling of the flow problems for the main airfoil and the flap. The special case of an atta...

The purpose of this research is to develop a MATLAB model which can calculate the aerodynamics, such as lift, drag, and pressure, on an airfoil as it changes shape. This model needs to be computationally efficient and should have reasonable accuracy. A constant strength doublet panel code, which takes thickness and camber distribution as inputs, is used to model the aerodynamics. This code has ...

This paper presented methods to determine the aerodynamic forces that acton an aircraft wing during flight. These methods are initially proposed for asimplified two degree-of-freedoms airfoil model and then are extensivelyapplied for a multi-degree-of-freedom airfoil system. Different airspeedconditions are considered in establishing such methods. The accuracy of thepresented methods is verifie...

A robust optimization method is developed to overcome point-optimization at the sampled design points. This method combines the best features from several preliminary methods proposed by the authors and their colleagues. The robust airfoil shape optimization is a direct method for drag reduction over a given range of operating conditions and has three advantages: (1) it prevents severe degradat...

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 new method using the cubic B-spline curves with nominal uniform knot set to parameterize the geometry is proposed to deal with shape optimization problems. In the method, the control points of the B-spline curves are set to be the design variables in the optimization scheme. A knot insertion algorithm has been introduced in order to keep the geometry unchanged whilst increasing the number of ...