时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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blowing sand (meteorology). Sand picked up locally from the surface and blown about in clouds or sheets. blowing snow (meteorology). Snow picked up locally from the surface by the wind and carried to a height of six feet or more. blowing spray (meteorology). Water particles picked up by the wind from the surface of a large body of water. blown boundary layer control (aerodynamics). A method of decreasing aerodynamic drag on the surface of an airplane wing. The boundary layer is the layer of air which flows in a random fashion directly over the surface of the wing. Blown boundary layer control uses high-velocity air blown through ducts or jets to energize, or add energy to, the boundary layer. Energizing this air speeds it up and causes it to flow straight across the wing. blowout plug. A safety plug on the outside skin of an aircraft fuselage near the installation of high-pressure oxygen or fire extinguisher agent. If, for any reason, the pressure of the gas in the cylinders rises to a dangerous level, the blowout plug will blow out and relieve the pressure. Colored disks in the blowout plugs identify the system that has been relieved in this manner. blowtorch. A hand-held torch that uses liquid gasoline as a fuel. Air is pumped into the fuel tank, and the liquid fuel sprays out into the burner where it becomes a vapor. The air compressed in the tank blows through the flame and intensifies it. Gasoline blowtorches have been replaced, to a great extent, by torches using propane or other liquified petroleum products as their fuel. bluckets (turbofan engine component). The portions of aft-fan blades that are in the exhaust of the core engine. Bluckets drive the fan by energy received from the hot gases leaving the core engine. blueprint. A type of engineering drawing used in the design and manufacture of aircraft, aircraft engines, and various components. Lines in the drawing appear white on a dark blue background. The original drawing is made with black ink on translucent drawing paper or cloth. This drawing is then used as a negative, and sensitized paper is exposed through the drawing by exposing it to a high-intensity light. After the exposure, the print is developed by washing it in water. Blueprints have been replaced in many engineering departments by prints made by the Ozalid process, in which the exposed sensitized paper is developed by exposing it to ammonia fumes. blush (aircraft finishing system defect). A defect in a lacquer or dope finish caused by moisture condensing on the surface before the finish dries. If the humidity of the air is high, the evaporation of the solvents cools the air enough to cause the moisture to condense. The water condensed from the air mixes with the lacquer or dope and forms a dull, porous, chalky-looking finish. This is called blush. A blushed finish is neither attractive nor protective. BMEP (brake mean effective pressure). The average pressure inside the cylinder of a reciprocating engine during the power stroke. |
