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Magnus force acting upon a rotating sphere passing in an incompressible viscous flow
Beck, Dominik ; Martinec, Zdeněk (advisor) ; Čadek, Ondřej (referee)
Classical results of hydrodynamics such as Stokes' force law and Kirchhoff's mo- ment (torque) law are re-derived for laminar viscous flow in the framework of modern compact simplified vector calculus notation. First perturbations of these laws are found and compared visually with experiments. The Magnus drag force on a rotating and moving sphere surrounded by an incompressible viscous New- tonian fluid is derived from the perturbation series of the Navier-Stokes equations in low speed regimes with a small Reynolds number.
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Motion of rotating spherical particles touching a wall
Chára, Zdeněk ; Vlasák, Pavel ; Keita, Ibrahima
The paper deals with an analysis of motion of rotating spherical particle in calm water, when the particle is in contact with a smooth, horizontal wall. The motion was visualized by a fast digital camera at 1000 frames/second. Based on software analysis the particle trajectories as well as rotational velocities were determined. Values of vertical, horizontal and rotational velocities were used as input parameters for numerical model and the results are compared with experimental data. Experiments were performed with glass particle of diameter 25 mm, initial values of rotational speeds varied from 500 to 3000 revolution per minute.
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Experimental evaluation of the drag torque, drag force and Magnus force acting on a rotating prolate spheroid
Lukerchenko, Nikolay ; Keita, Ibrahima ; Kvurt, Y. ; Miles, Jiří
The drag torque, drag force and Magnus force acting on a spheroid rotating around its axis of symmetry and moving perpendicularly to this axis in initially quiescent water were studied using experimental data and numerical simulation. The prolate spheroid with ratio of the axes 4/3 was speeded up in special device, which ensured the required rotational and translational velocity in the given plane. A video system was used to record the spheroid motion in water. Using the video records the spheroid translational and angular velocities and trajectory of its center were determined and compared with the results of the numerical simulation. The dependences of the coefficients of the drag torque, drag force and Magnus force on the Reynolds number and dimensionless angular velocity were obtained.
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Experimentální výzkum Magnusovy síly působící na hladkou kouli při vysokých Reynoldsových číslech
Kharlamov, Alexander ; Chára, Zdeněk ; Vlasák, Pavel
The paper describes the results of experimental research dealing with rotating smooth spherical particles moving quasi-steadily in calm water. The motion of the particles was recorded by a digital video camera. The kinematics of the particles motion was analyzed numerically. The dimensionless Magnus force coefficient, the Reynolds number Re and spin parameter Γ (ratio of peripheral sphere velocity and translational velocity) were evaluated from the time series of the particle coordinates and its angle of rotation. The Magnus force was determined as a function of the Reynolds number and spin parameter for 3000 < Re < 42000 and 0.1 < Γ <7. The results were compared with results from literature and overall data were fitted by a simple function valid for 0.5 < Re < 140000 and 0.1 < Γ <10.
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Magnus and Drag Forces Acting on Golf Ball
Kharlamov, Alexander ; Chára, Zdeněk ; Vlasák, Pavel
The paper describes the results of experiments with a rotating golf ball moving quasi-steadily in calm water. The motion of the ball was recorded on a digital video camera. The Cartesian coordinates and the angle of rotation of the ball were determined from the records of motion. The dimensionless drag force coefficient, Magnus force coefficient and translational and rotational Reynolds numbers were calculated from the time series of the ball coordinates and the angle of rotation for each recorded frame. The calculated data were averaged over rectangular cells on experimental domain on the plane of translational and rotational Reynolds numbers, i.e. 1.2 104 < Re < 1.6 104 and 3.8 103 < Reω < 2.7 104. The coefficients were presented in tabulated form.
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