2 results about "Aerodynamic drag" patented technology

Windblown particles are controlled by a porous tubular control device formed from a sheet of netting material having a plurality of interconnected webs which define a plurality of apertures. The sheet of netting material assumes a three-dimensional tubular configuration. The tubular configuration is oriented to confront the wind and cause the wind blown particles to flow through the apertures of two vertically oriented portions of the tubular netting sheet to create aerodynamic drag and turbulence altering effects which stabilize, deposit and retain the windblown particles. The control device is effective in preventing the wind erosion of snow, sand or dust over an area much greater than the area occupied by the device.

The invention relates to the field of missile parts, in particular to a folding missile lifting lug structure. A lifting lug hiding room is arranged in a missile body, and comprises a lifting lug, a torsional spring, a rotating shaft, a bearing, a plate spring and a positioning pin, wherein the bearing is fixed in the lifting lug hiding room of the missile body; the lifting lug is movably mounted in the lifting lug hiding room through the rotating shaft and the bearing; the rotating shaft penetrates the torsional spring; one end of the torsional spring is clamped in the lifting lug, and the other end of the torsional spring is clamped in the missile body; the torsional spring drives the lifting lug to be rotated in the lifting lug hiding room; the positioning pin is inserted in the missile body along the side of the lifting lug to prevent the lifting lug from rotating. The folding missile lifting lug structure has the beneficial effects that first, the lifting lug is hidden in the missile body, so that no projections exist on the surface of the missile body, the aerodynamic drag is reduced, and the high speed flight is benefited; second, the folding missile lifting lug structure has a simple structure, and is used flexibly, conveniently and reliably; third, after being unfolded, the lifting lug is suitable for ground hoisting and transporting, and after being folded, the lifting lug is not easy to impact.