This study aimedto investigatethe spatiotemporal variation of hydrodynamic variables around a sphere rigidlyϐixed to the bottom of a sloshing tank.The experimental measurement of the variations of dynamic variables ar...This study aimedto investigatethe spatiotemporal variation of hydrodynamic variables around a sphere rigidlyϐixed to the bottom of a sloshing tank.The experimental measurement of the variations of dynamic variables around a body in a sloshing tank requires non‑intrusive measurements that are usually expensive and sometimes inappli‑cable.Therefore,the numerical model could serve as a cost‑effective tool for such problems.A two‑stage analysis was conducted.In theϐirst stage,an experimental study was carried out in a testing system comprising a water tank with uniaxial freedom of movement constructed on a monorail operated by a computer‑controlled step motor.The primary objective of the experiments was to generate reliable data for calibrating the numerical model.During the experiments,the tank’s movements were recorded using an accelerometer and ultrasonic sensors with a sampling frequency of 200 Hz for each.The accelerometer and ultrasonic sensor data were used to impose the motion of the sloshing tank into a Reynolds‑Averaged Navier‑Stokes(RANS)‑based numerical model.The video recordings,which comprised temporalϐluctuations of the water surface,were used to calibrate the Model 1.Once theϐirst numerical model was calibrated based on water surface level records using image processing methods,the second numerical model was constructed to accommodate a rigid spherical body with a 17 mm diameter connected to the bottom of the sloshing tank. The initial and boundary conditions used in the second numerical model were identical to those used in the ϐirst model to measure the spatiotemporal ϐluctuations of the surrounding spherical body’s kinematic and dynamic variables, respectively. The ϐindings revealed that sloshing motion exerts a signiϐicant impact on the boundary layer separation process around the sphere. It was also witnessed that the stage of the sloshing motion controls the temporal lag between the pressure, velocity and water surface level.展开更多
文摘This study aimedto investigatethe spatiotemporal variation of hydrodynamic variables around a sphere rigidlyϐixed to the bottom of a sloshing tank.The experimental measurement of the variations of dynamic variables around a body in a sloshing tank requires non‑intrusive measurements that are usually expensive and sometimes inappli‑cable.Therefore,the numerical model could serve as a cost‑effective tool for such problems.A two‑stage analysis was conducted.In theϐirst stage,an experimental study was carried out in a testing system comprising a water tank with uniaxial freedom of movement constructed on a monorail operated by a computer‑controlled step motor.The primary objective of the experiments was to generate reliable data for calibrating the numerical model.During the experiments,the tank’s movements were recorded using an accelerometer and ultrasonic sensors with a sampling frequency of 200 Hz for each.The accelerometer and ultrasonic sensor data were used to impose the motion of the sloshing tank into a Reynolds‑Averaged Navier‑Stokes(RANS)‑based numerical model.The video recordings,which comprised temporalϐluctuations of the water surface,were used to calibrate the Model 1.Once theϐirst numerical model was calibrated based on water surface level records using image processing methods,the second numerical model was constructed to accommodate a rigid spherical body with a 17 mm diameter connected to the bottom of the sloshing tank. The initial and boundary conditions used in the second numerical model were identical to those used in the ϐirst model to measure the spatiotemporal ϐluctuations of the surrounding spherical body’s kinematic and dynamic variables, respectively. The ϐindings revealed that sloshing motion exerts a signiϐicant impact on the boundary layer separation process around the sphere. It was also witnessed that the stage of the sloshing motion controls the temporal lag between the pressure, velocity and water surface level.
