Journal of the Korean Society of Visualization (한국가시화정보학회지)

The Korean Society of Visualization (한국가시화정보학회)
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Numerical study of a freely falling rigid sphere on water surface

수면 위 자유 낙하 및 충돌하는 강체 구의 수치해석 연구

  • Ku, BonHeon (School of Mechanical Engineering, Pusan National University) ;
  • Pandey, Deepak Kumar (School of Mechanical Engineering, Pusan National University) ;
  • Lim, Hee-Chang (School of Mechanical Engineering, Pusan National University)
  • Received : 2021.05.29
  • Accepted : 2021.07.12
  • Published : 2021.08.31
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Abstract

Numerical studies on the hydrodynamics of a freely falling rigid sphere in bounded and unbounded water domains are presented having investigation on the drag coefficient, normalized velocity, surface pressure and skin friction coefficient as a function of time. Two different conditions of the bounded and unbounded domains have been simulated by setting the blockage ratio. Four cases of bounded domains (B.R. = 1%, 25%, 45%, 55%, 65% and 75%) have been taken, whereas the unbounded domain has been considered with 0.01%. In the case of the bounded domain (higher values of B.R.), a substantial reduction in normalized velocity and increase in the drag coefficient have been found in presence of the bounded domain. Moreover, bounded domains also yield a significant increase in the pressure coefficient when the sphere is partially submerged, but the insignificant effect is found on the skin friction coefficient. In the case of the unbounded domain, a significant reduction in normalized velocity occurs with a decrease in Reynolds number (Re) and also increase in the drag coefficient.

Keywords

Acknowledgement

이 과제는 부산대학교 기본연구지원사업(2년)에 의하여 연구되었음.

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