Drag coefficients of the downstream cylinder in a tandem arrangement of two models aligned with the flow are shown in this work. The models. which experienced vortex-induced vibrations with wake inteiference. had an external diameter of 16 mm and a total length of 1.5 m giving an aspect ratio of about 94. More than 400 runs were carried out in a water flume with only the lower 40% of the models...

Raptors - falcons, hawks and eagles in this study - such as peregrine falcons (Falco peregrinus) that attack distant prey from high-speed dives face a paradox. Anatomical and behavioral measurements show that raptors of many species must turn their heads approximately 40 degrees to one side to see the prey straight ahead with maximum visual acuity, yet turning the head would presumably slow the...

in this paper particle swarm optimization with smart inertia factor (pso-sif) algorithm is proposed to solve combined heat and power economic dispatch (chped) problem. the chped problem is one of the most important problems in power systems and is a challenging non-convex and non-linear optimization problem. the aim of solving chped problem is to determine optimal heat and power of generating u...

A snake-like robot can move in not only the dry ground but also various viscous environments of water, mud, and clay by exhibiting undulating motions. To construct numerical model including fluid–structure interaction for under above-mentioned environments, added mass drag coefficients must be identified via experimentation because they depend on shape body, roughness skin, viscosity fluid. In ...

The Arctic sea ice cover is thinning and retreating, causing changes in surface roughness that in turn modify the momentum flux from the atmosphere through the ice into the ocean. New model simulations comprising variable sea ice drag coefficients for both the air and water interface demonstrate that the heterogeneity in sea ice surface roughness significantly impacts the spatial distribution a...

Accurate estimates for the drag coefficients of a satellite are important in reducing the biases in densities derived from satellite drag measurements as well as explicitly reducing the errors in orbit prediction. This develops a approach to estimate the drag coefficient for debris objects with known shape models.This paper focuses on rocket bodies in particular. The attitude and angular veloci...

An experimentalinvestigation has been made of the subsonic lift, drag and longitudinal stability characteristics of models representing some alternative slender airbus configurations. For the same wing planform of aspect ratio 1.4 the lift, drag and pitching moment have been measured for two wings of maximum thickness/chord ratio 4 and 9 per cent respectively, both without and with various body...