跨音速飞机头部进气道前空速管的气动补偿计算

现有飞机的气压高度表误差往往较大,如Ma_∞=0.9时高度误差达300m,严重影响了飞机的低空、超低空飞行。为了减小气压高度表的指示误差,通常采用补偿方法。气动补偿是有效的方法之一。 由于机头及进气道的阻塞作用,机头前方将产生一个正压场。受正压场影响,有限长空速管所测静压并非飞机所在高度的真实静压,其中包含较大的静压误差C_(pw)。气动补偿原理就是选用特定外形的补偿空速管,使气流流经静压孔时产生一定量的补偿负压

COMPUTAION OF THE COMPENSATION PITOT TUBE IN FRONT OF THE NOSE INLET OF AN AIRCRAFT AT TRANSONIC SPEED

The aerodynamically compensating pitot tube, which is used to reduce the error of the pressure altimeter of an airplane,is studied by the mixed difference computation of transonic small disturbance. The static pressure distribution of the compensating pitot tube and the positive pressure field in front of the nose inlet are calculated. The static pressure error produced by the nose inlet is compensated by the negative pressure at the static pressure orifice of the pitot tube. The. computed results and prediction agree very well with the wi nd tunnel and flight test data.