Notwithstanding the developments made in recent decades in wind effects on structures, there is a need to revisit the current paradigms and to look for improved understanding concerning the nature of wind field, associated aerodynamics and the resulting load effects in light of the emerging themes: non-stationarity/non-homogeneity/transient wind events; mechanical/convective turbulence; unstead...

In support of the Columbia Accident Investigation, inviscid computations of the aerodynamic characteristics for various Shuttle Orbiter damage scenarios were performed using the Felisa unstructured CFD solver. Computed delta aerodynamics were compared with the reconstructed delta aerodynamics in order to postulate a progression of damage through the flight trajectory. By performing computations...

An overview of recent experimental results on instability and dynamics of jets at low Reynolds numbers is given. Round and plane, macro and micro jets are under the consideration. Basic features of their evolution affected by initial conditions at the nuzzle outlet and environmental perturbations are demonstrated.

A field trial was conducted to test the existence of subsonic (Vp < 331 m/s) P-waves previously reported in the literature. A 1-m-long reverse profile was acquired with three-component (3C) geophones on a sandy silt (unified classification ML). The silt had a porosity of 54%, a degree of water saturation of 63%, and a plasticity index of 10. No subsonic P-waves were observed, although highfrequ...

In this paper, we study irrotational subsonic and subsonic-sonic flows with general conservative forces in the exterior domains. The indicate new Bernoulli law naturally. For case, introduce a modified cut-off system depending on which needs varied Bers skill, construct solution by variational formula. Moreover, comparing previous results, our result extends pressure-density relation to case. A...

The objective of this study is to minimize the drag coefficient of aerodynamics bodies for a specified design Reynolds number regime. With the aerodynamics model the gradient of the objective function (drag coefficient) cannot be determined analytically. Furthermore, it is expected that the objective function is multi-modal, i.e. it shows more than one minimum. Therefore, the optimization algor...

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 ...

Hypersonic systems for space access and with strike capability are currently being researched by the Air Force. Flight testing and clearing them is particularly challenging, because of the speeds at which they operate. When anything unexpected occurs, the time to react is so short that the tested system must be destroyed. Therefore, the predictive analysis of these systems is essential for dete...

A computational study was performed to determine the predictive capability of a Reynolds averaged Navier-Stokes code (CFL3D) for two-dimensional and three-dimensional multielement high-lift systems. Three configurations were analyzed: a three-element airfoil, a wing with a full span flap and a wing with a partial span flap. In order to accurately model these complex geometries, two different mu...

André V. G. Cavalieri, Peter Jordan, Tim Colonius and Yves Gervais Journal of Fluid Mechanics / Volume 704 / August 2012, pp 388 ­ 420 DOI: 10.1017/jfm.2012.247, Published online: 03 July 2012 Link to this article: http://journals.cambridge.org/abstract_S0022112012002479 How to cite this article: André V. G. Cavalieri, Peter Jordan, Tim Colonius and Yves Gervais (2012). Axisymmetric superdirect...