The schematic diagram of the experimental setup is shown in
Fig. 2.
In this investigation, a counter flow RanqueeHilsch vortex tube
with (L ¼ 250 mm, D ¼ 18 mm) L/D ratio equal to 13.88 was applied.
Four different hot control valves with different shapes (Spherical,
plate shape, cone shaped and truncated cone control valve) have
been manufactured and used in the tests as shown in Fig. 3. The
schematic diagram of the test setup is shown in Fig. 2. The inlet
pressures of the counter flow vortex tube have been measured by
use of a pressure gauge ( 0.5%) as shown in Fig. 2. The mass flow
rates at the cold and hot exhausts of the counter flow vortex tube
have been determined by use of rotameters. The temperatures of
the pressurized air at the inlet, and the cold and hot exits were
determined by employing of a digital thermometer with 0.1%
precision tolerances, and the measured temperature magnitudes
have been changed into Kelvin (K) unit. Temperature probes of the
digital thermometer were adjusted into the Ø2 mm hole which was
drilled at the center of the counter flow vortex tube and 1.25 cm
away from the cold and the hot exhausts. The throttle valves have
been placed on the hot outlet of the main tube in order to adjust the
mass flow rate of the hot air. Before starting the experimental tests,