As wind turbines continue to grow larger, problems associated with adverse aerodynamic loads will grow more critical. Thus, the wind energy technical community has begun to seriously consider the potential of aerodynamic control methodologies for mitigating adverse aerodynamic loading. Spatial and temporal attributes of the structures and processes present in these flow fields hold important im...

The purpose of this paper is to explore the nature of aerodynamic drag losses, relate them to aerothermodynamic losses in the aircraft as a whole, and develop methods for assessing drag chargeability. The concept of the aerodynamic “loss deck” is introduced and applied to the analysis of an F-5E fighter. It is shown that this loss deck can be used to integrate aero losses through the vehicle mi...

A DLM-based aerodynamic simulator for flutter is used to identify some of the most important aerodynamic drivers for the T-Tail flutter mechanism of a complete aircraft. The simulator is using the Modal Descrambling Factoring Method, which permits individual variations of each direct and each interference aerodynamic force, moment and hinge moment independently of any other force or moment. The...

Aerodynamic forces on bridges are commonly separated into static, self-excited, and buffeting force components. By delving into the relationships among force descriptors for static, self-excited, and buffeting components, novel perspectives are developed to unveil the subtle underlying complexities in modeling aerodynamic forces. Formulations for airfoil sections and those based on quasisteady ...

Recent enhancements to the development of CFD-based unsteady aerodynamic and aeroelastic reduced-order models (ROMs) are presented. These enhancements include the simultaneous application of structural modes as CFD input, static aeroelastic analysis using a ROM, and matched-point solutions using a ROM. The simultaneous application of structural modes as CFD input enables the computation of the ...

purpose : to compare visual outcome of aspheric and spheric intraocular lenses (iols) implantation in patients with age-related cataract in terms of visual acuity (va), contrast sensitivity (cs) and spherical aberration methods : in this prospective randomized interventional study, 59 consecutive cases of senile cataract who had been admitted for cataract surgery to farabi eye hospital, tehran,...

In the present study, the lenses and ciliary bodies of 20 ostrich eyes were studied macroscopically and microscopically. The histological slides were studied after staining by hematoxylin and eosin, Verhoeff, Van Gieson, and periodic acid-Schiff (PAS). Posterior surface of lens was more convex than its anterior surface. The average lens diameter and thickness were respectively measured as 1.43 ...

This paper examines feasibility and performance issues in using Control Moment Gyroscopes (CMGs) to control the attitude of a fixed-wing aircraft. The paper describes a control system structure that permits allocating control authority and bandwidth between a CMG system and conventional aerodynamic control surfaces to stabilize a vehicle with neutral aerodynamic stability. A simulation study ex...