论文部分内容阅读
以前的德尔它运载火箭在第一级主发动机关机(MECO)以前不久,就已经受了一个纵向的动态不稳定性振动,即“POGO”。为了防止这种动态现象的发生,就必须在 MECO 之前将主液氧箱的最低限度的释放压力从31.0psig 增加为53.0psig。必须设计这样一个系统,它能在飞行的某时刻增加贮箱的释放压力,以使贮箱底部的静压足够低,从而避免超过结构的极限。因此,为满足这些要求研制了德尔它Ⅱ主液氧箱双级增压系统。到目前为止,德尔它Ⅱ已经进行了9次飞行,而且所设计的主液氧箱双级增压系统已按预期的情况工作,并成功地消除了MECO 时的“POGO”问题。
The previous Deltas launch vehicle had suffered a longitudinal dynamic instability vibration called “POGO” shortly before the first main engine shutdown (MECO). In order to prevent this dynamic phenomenon, it is necessary to increase the minimum release pressure of the main liquid oxygen tank from 31.0 psig to 53.0 psig before MECO. A system must be designed that increases the release pressure of the tank sometime during the flight so that the hydrostatic pressure at the bottom of the tank is low enough to avoid exceeding structural limits. Therefore, in order to meet these requirements, we developed a two-stage pressurization system for its main liquid oxygen box. So far, Delft II has flown nine flights and the designed two-stage primary fluid oxygen tank pressurization system has been working as expected, successfully eliminating the “POGO” issue at MECO.