The
angle between the model vertical plane of symmetry and the flow direction
also effects the flow
field. Change the angle of the models with respect
to the flow and observe the flow pattern on each side
of the shape. Is it
the same? Can you find some systematic trend in this behavior? Are vortices being
shed
by your model? How does this depend on the flow velocity?
Similar
observations and Reynolds number determinations may be made on a model
bike and rider either with or without a flat plate mounted normal to the flow
on the handlebars. A study of the flow and its dependance on Reynolds number
may provide insight into the cause of increased air resistance with the
full-scale bike.
Introduce the dye into the flow using a fine tube so
that it enters the flow at different locations with respect to the model. Start
with a relatively low water velocity and introduce dye in front of the model
at about its mid-point both horizontally and vertically. Observe how the dye
behaves and how it tracks the model surface. Pay particular attention to the
flow in the wake region downstream of the model. Systematically alter the
flow velocity to increase the Reynolds number and note how the boundary layer
and flow behavior changes. Move the position of dye injection to provide a clear
picture of the flow around the model. Make sketches of the observed flow
patterns. |
