说New words

•        Augment加强

•        Combat战斗

•        Oxygen氧气

•        Flame 火焰

•        Concentrate集中

•        Restriction限制、约束

•        Powerplant 动力设备

•        Stabilizer稳定器

•        Lit 点燃

•        Gutter槽

•        Eyelid眼睑、半圆式调节喷口

•        Interlocking互锁

•        Atomize雾化

•        Catalytic催化的

•        Platinum铂金

•        Streak条纹

•        Spontaneously自发地

•        Intensity强度

•        Concentric同心的

•        Blunt 迟钝的、钝的

•        Insulation绝缘

•        Accommodate适应

•        Heatshield隔热板

•        Corrugation波纹

•        Overlapping重叠、交叉

•        Tile 瓦片、瓷砖

•        Rivet 铆钉、铆接

•        Deterioration变质

•        Hinge 铰链、转轴

•        Ram 撞击、塞进

•        Energized带电的、供给能量、精力充沛

•        Sleeve套筒

•        Progressively逐步

•        Lever 推杆、操纵杆

•        Neglecting忽略

•        Squareroot 平方根

•        Obtainable可获得的

•        Duration续航时间

•        Peak 峰

读Sentence

•        1.Afterburning (or reheat) is a method of augmenting the basic thrust of anengine to improve the aircraft take-off, climb and (for military aircraft)combat performance. The increased power could be obtained by the use of alarger engine, but as this would increase the weight, frontal area and overallfuel consumption, afterburning provides the best method of thrust augmentationfor short periods.

•        2.Afterburning consists of the introduction and burning of fuel between the engineturbine and the jet pipe propelling nozzle, utilizing the unburned oxygen inthe exhaust gas to support combustion (fig. 16-1). The resultant increase inthe temperature of the exhaust gas gives an increased velocity of the jetleaving the propelling nozzle and therefore increases the engine thrust.

•        9. Inview of the high temperature of the gases entering the jet pipe from theturbine, it might be assumed that the mixture would ignite spontaneously. Thisis not so, for although cool flames form at temperatures up to 700 deg. C.,combustion will not take place below 800 deg. C. If however, the conditionswere such that spontaneous ignition could be effected at sea level, it isunlikely that it could be effected at altitude where the atmospheric pressureis low. The spark or flame that initiates combustion must be of such intensitythat a light-up can be obtained at considerable altitudes.

•        12.The afterburning jet pipe is made from a heat- resistant nickel alloy andrequires more insulation than the normal jet pipe to prevent the heat ofcombustion being transferred to the aircraft structure. The jet pipe may be ofa double skin construction with the outer skin carrying the flight loads andthe inner skin the thermal stresses; a flow of cooling air is often inducedbetween the inner and outer skins. Provision is also made to accommodateexpansion and contraction, and to prevent gas leaks at the jet pipe joints.

•        16.Since large fuel flows are required for afterburning, an additional fuel pumpis used. This pump is usually of the centrifugal flow or gear type and isenergized automatically when afterburning is selected. The system is fullyautomatic and incorporates 'fail safe' features in the event of an afterburnermalfunction. The interconnection between the control system and afterburner jetpipe is shown diagrammatically in fig. 16-5.

读全文并回答以下问题：

•       What is the working principle of the afterburner?

•       For low by-pass engine, what is the way to achieve afterburning?

•       What is the working principle of the heatshield?

•       Can a afterburner achieve complete combustion?