摘要
为了考察小空化数水下射弹自然减速运动过程中的阻力系数,建立了水下射弹二维轴对称数值模型.采用动网格技术,研究了不同初始空化数、不同长细比的水下射弹小空化数自然减速运动过程中的模型阻力系数随时间的变化规律.数值计算结果表明,同一超空泡减速运动过程中,空泡的长度发展滞后于厚度发展.同一模型长细比下,模型阻力系数随时间呈准线性上升.模型减速过程中,空化数随时间不断上升,当空化数较低时,阻力系数曲线斜率较小,阻力系数几乎不随时间变化,当空化数较高时,阻力系数曲线斜率大,随时间上升较快.另外,当初始空化数较低时,随初始空化数的降低,模型阻力系数变化较小,此时继续降低初始空化数,其减阻效果不再明显提升.
A 2D axisymmetrical numerical model was established to investigate the drag coefficient during the natural deceleration of an underwater projectile with supercavity at a relative low cavitation number.Based on dynamic mesh technology,the variations of unsteady drag coefficient with time have been studied under several model slenderness ratios at a range of initial cavitation number.The simulation results show that the variations of the supercavity length lag behind that of the supercavity thickness during the same supercavitation movements.Whatever the model slenderness ratio is,the model drag coefficients are quasi-linear ascent over time.The cavitation number is ascent over the deceleration,when the cavitation number is low,the curve slope of the drag coefficients is small and the drag coefficient is almost unchanged and when the cavitation number is high,the curve of the drag coefficient is quick ascent.When the initial cavitation number is low enough,the changes of the drag coefficient with the initial cavitation number are very small and the variation of the effect of supercavitation drag reduction with the descent of the initial cavitation number is no longer obvious.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2013年第3期22-27,共6页
Journal of Harbin Institute of Technology
基金
国家自然科学基金资助项目(51149003)
关键词
阻力系数
超空泡
自然减速
射弹
非定常
动网格
drag coefficients
supercavity
natural deceleration
projectile
unsteady
dynamic mesh
