Modular wind tunnel
This wind tunnel was designed in the Institute of Thermomechanics
CAS between 2000 and 2002, and has been operational since 2004.
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Schematic of the modular wind
tunnel |
Air enters through a silicagel dryer
and pebble and cloth filters 1 into the entrance room, and then through honey-combs
and settling screens 2, 3, and 4, into the contraction 5, and a straight test
section modulus 6. Further downstream are a transitional element 7, compensator
8, 9, pipe 10, control nozzle 12, bellows 13, spherical fast-acting gate 14,
hand-driven closing valve 15, diffuser 16, and connection to the main duct
and the vacuum storage.
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The modular wind tunnel with a straight closed
test section and the optical bench |
With a special test section for radial
inflow turbine cascades it is possible to carry out experimental investigation
of radial turbine cascades, including flow visualization and loss measurements
using a special traversing mechanism, moving the traversing probe on a circular
path behind the cascade.
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The modular wind tunnel with a test section for radial
inflow turbine cascades, and with the traverzing mechanism |
The uncovered traversing
mechanism |
In the modular wind tunnel it is now possible to carry out
experiments of quite fundamental character, for which in the past we had a small high speed wind tunnel
attached to the main duct by a 300mm pipe and quick operating valve. This wind tunnel was dismantled,
though most of our experimental investigation of the flow in relatively narrow channels had been
made in it.
It was used mainly with one-purpose
test sections, and test sections with variable width, to study the flow separation,
quantitative and qualitative changes in the terminal shock wave – boundary
layer interaction, transition from supersonic to subsonic flow in narrow channels
in a pseudoshock wave, the effect of flow non-uniformity on the transonic
flow in the critical cross section, flow past blunt trailing edges, etc. In
most of the cases the width of the test section could be changed in the range
from 10 to 120 mm (see figure below).
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Test sections for the small
high speed wind tunnel |