CAJ | 학술논문

通过相关的理论和试验对比研究了圆球倾斜入水冲击压力的性质，解释了冲击压力的振荡现象。试验以一个直径15．24 cm的圆球为对象，设计了控制球体倾斜入水的“单摆”装置，同步记录了圆球入水初期的流场状态和表面压力。采用Faltinsen的近似公式对比了入水初期压力载荷的变化，用理想不可压流体中气泡的非线性振动方程解释了冲击压力下降阶段出现的振荡性质。理论和试验对比表明：圆球的倾斜入水与垂直入水相比，迎撞面压力峰值大，下降迅速；背撞面压力峰值显著减小，压力下降平稳缓慢；所用的近似公式在量级上可以估算冲击的设计载荷，Rayleigh方程可用来有效解释含气泡冲击的压力振荡性质。
통과상관적이론화시험대비연구료원구경사입수충격압력적성질，해석료충격압력적진탕현상。시험이일개직경15．24 cm적원구위대상，설계료공제구체경사입수적“단파”장치，동보기록료원구입수초기적류장상태화표면압력。채용Faltinsen적근사공식대비료입수초기압력재하적변화，용이상불가압류체중기포적비선성진동방정해석료충격압력하강계단출현적진탕성질。이론화시험대비표명：원구적경사입수여수직입수상비，영당면압력봉치대，하강신속；배당면압력봉치현저감소，압력하강평은완만；소용적근사공식재량급상가이고산충격적설계재하，Rayleigh방정가용래유효해석함기포충격적압력진탕성질。
Characteristics of impacting pressure during the initial stage of a sphere water entry was studied based on a series of model tests.A pendulum instrument was set up for a 6-inch diameter sphere to impact into calm water obliquely.Water splash and the sphere's surface pressure were recorded synchronously.The test results showed that the peak pressure on the impact-facing surface drops sharply and is much higher than that on the opposite surface.Time series of pressure during small submergences were compared with the results obtained with Faltisen's theory formula.It was shown that the formula is able to estimate the impact design loads with a small penetration depth;the nonlinear Rayleigh equation for a spherical gas bubble in an ideal incompressible fluid is effective to explain approximatly pressure oscillation.