We consider the aerodynamics of football, specifically, interaction between a ball in flight and ambient air. Doing so allows one to account for characteristic range trajectories balls flight, as well their anomalous deflections may be induced by striking either with or without spin. The dynamics viscous boundary layers is briefly reviewed, its critical importance on highlighted. Magnus effect ...

Abstract Comprehensive understanding of propulsive jet aerodynamics and aeroacoustics is key to engine design for reduced noise infra-red signature in civil military aerospace, respectively. Illustrated examples are provided other aerodynamic/aeroacoustic problems involving development, including chevron nozzles, increased jet/wing/flap interference (as fan diameter increases), high acoustic en...

This paper explains how the solutions of appropriate adjoint equations can be used to estimate the errors in important integral quantities , such as lift and drag, obtained from CFD computations. These error estimates can be used to obtain improved estimates of the integral quantities, or as the basis for optimal grid adaptation. The theory is presented for both nite volume and nite element app...

OBJECTIVE The aim of this work is to study the hitherto unclear aerodynamic parameters of the pseudo-glottis following total laryngectomy. These parameters include airflow rate, sub-pseudo-glottic pressure (SubPsG), efficiency and resistance, as well as sound pressure level (SPL). PATIENTS AND METHODS Eighteen male patients who have undergone total laryngectomy, with an age range from 54 to 7...

Domain decomposition (Krylov-Schwarz) iterative methods are natural for the parallel implicit solution of multidimensional systems of boundary value problems that arise, for instance, in aerodynamics. They provide good data locality so that even a high-latency workstation network can be employed as a parallel machine. Matrix-free (Newton-Krylov) methods are natural when it is unreasonable to co...

A valuable new resource being developed for today’s soldier are small ducted fan VTOL UAVs. Although beneficial in many ways, a major operational problem of ducted fan vehicles is precise control when flying in crosswinds and turbulent conditions in general. There are two significant, inherent issues associated with ducted fan control in crosswinds; 1) lateral momentum drag and 2) a duct stabil...

PURPOSE To analyze the impact of body weight and body fat volume on selected parameters of vocal quality, phonatory range, and aerodynamics in females. METHODS Based on measurements of body mass index in combination with body fat volume, 29 normophonic female subjects were classified as normal weight, underweight, and obese. Voice quality was investigated via auditory-perceptual ratings of br...

This work is a synthesis of our current understanding of the mechanics, aerodynamics and visually mediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparativ...