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基于势流理论,采用积分方程方法,研究了薄楔体后部非定常自然超空泡流问题。应用时间有限差分离散化方法,得到了积分方程的数值解。预测了楔角和空化数作各种变化时,超空泡长度的非定常变化过程。楔角或空化数变化频率越高,空泡长度的变化越小,相对滞后时间越长。 相似文献
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Based on an integral equation method, the unsteady supercavitating flow around a slender cone cavitator is studied. The shape and length of supercavity is calculated respectively by using a finite difference time discrete method. Their characteristics varying with the cone angle and cavitation number are investigated respectively. It can be seen obviously that the change of supercavity is characterized by retardation and waviness. 相似文献
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楔体外部超空泡形状预测 总被引:7,自引:0,他引:7
研究了薄楔体外部定常和非定常超空泡流问题.采用时间有限差分离散化方法求解超空泡流积分方程,得到了问题的数值解.给出了Froude数对铅垂超空泡长度和形状的影响,以及楔角或空化数作非周期变化,特别是较高频率脉冲变化时,超空泡长度和形状的非定常变化过程.应用Logvinovich空泡独立膨胀原理对空泡形状的非定常变化过程作了定性解释. 相似文献
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研究了锥体空化器变速运动时非定常自然超空化流问题。基于势流理论,通过在对称轴上分布奇点(源和汇)的方法,建立了变速运动超空泡的积分方程。应用时间有限差分离散化方法,对问题进行了数值求解。分析了锥体空化器在做变速运动时(如速度脉冲变化、加速或减速等),超空泡长度和形状的非定常变化规律。同时,对基于本文方法得到的结果与已有理论的计算结果作了定性比较。本文的分析和预测结果可望为水下航行体空化器的分析与设计起到指导和数据参考作用。 相似文献
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采用积分方程方法,研究了楔形体外部自然超空泡流问题。提出了楔形体在静止流体中做变速运动所引起的非定常超空泡的积分方程。作为特例,得到了均匀来流时非定常超空泡的积分方程。应用时间有限差分离散化方法和有限差分法对积分方程进行了求解,得到了楔形体做变速运动、楔角变化、空化数变化、小扰动空化流等各种情况下的数值解。数值结果表明:非定常超空泡具有时滞性和波动性。楔体做变速运动时,加速度越大,时间滞后越长。在匀减速运动时,空泡不封闭,可能有回注射流发生。扰动频率越高,空泡长度变化越小,时间滞后越长。扰动以波动形式沿着空泡表面传播,传播速度为来流速度。该文所得到的结果,对于非定常超空化水翼的设计和分析能够起到参考作用。 相似文献
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Supercavitating flow around a slender symmetric wedge moving at variable velocity in static fluid has been studied. Singular integral equation for the flow has been founded through distributing the sources and sinks on the symmetrical axis. The supercavity length at each moment is determined by solving the singular integral equation with finite difference method. The supercavity shape at each moment is obtained by solving the partial differential equation with variable coefficient. For the case that the wedge takes the impulse and uniformly variable motion,numerical results of time history of the supercavity length and shape are presented. The calculated results indicate that the shape and the length of the supercavity vary in a similar way to the case that the wedge takes variable motion,and there is a time lag in unsteady supercavitating flow induced by the variation of wedge velocity. 相似文献
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