The
Saltation wind tunnel is designed to simulate particle flow in
saltation. It consists of four major sections, the entrance,
flow development section, test section, and diffuser. The
overall length of the tunnel is 13 meters and is typical of
many laboratory wind tunnels studying particle flow.
The
entrance section consists of a 0.48 m long contraction area
having a ratio of 5:1 equipped with honeycomb flow
straighteners to reduce the freestream turbulence level. The
7.32 m flow development section has diverging walls and
is composed of three individual sections which are each 2.44 m
(8 feet) long and made of plywood. The Plexiglas test section
is 2.44 m in streamwise length and 0.47 m high by 0.8 m wide
in the cross section. The diffuser, 2.8 m in length, has an
expansion area ratio of 13:1 which provides a continuous
transition from the rectangular cross section of the test
section to a circular cross section for the fan.
The
tunnel is equipped with a 3 hp, variable speed DC motor that
rotates an 8-blade fan. An AC/DC power converter supplies
power to the motor, and has controllable air speed inside the
tunnel of up to 20 m/s.
