Abstract:
This paper proposes a new analysis technique to find the
kinematics and dynamics of a single particle immersed in a fluid
in a three-dimensional metric frame. Because the technique is
entirely based on stereo-vision using only one camera attached
to a stereo adapter, it offers great versatility and simplicity, and
it does not cause any alteration to the physics of the studied
phenomena, therefore ensuring that the interaction between the
solid and its neighboring fluid stays undisturbed. Particle
velocity, drag force, and orientation, represented through the
angle of incidence, were estimated within the metric frame by
means of digital image processing, vector algebra, and
differential geometry operations. The methodology was first
validated by analyzing the motion of three spheres settling in a
fluid at different Reynolds numbers, where a close agreement
between the coefficients of resistance determined here and those
computed from literature correlations was obtained. The motion
of two cylinders in free fall was then investigated, and it was
found that at low Reynolds numbers a cylinder falls with fixed
orientation in a straight path whilst for large Reynolds numbers
it exhibits regular oscillation and travels in a sinusoidal fall path,
thus causing an increment in the drag coefficient as the angle of
incidence also augments.
Description:
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.
