| Summary: | The purpose of this study was to look at the influence of the inlet air
pressure variations and variations in the number of nozzles used in Ranque-Hilsch
vortex tube (shortened to RHTV), and then finally get the relationship between
the decrease of temperature at the end of cold oulet section (�Tc) and cooling
efficiency (ï�¨v) toward in changes of the cold mass fractions (ï�c). To obtain of
RHTV results performances, two steps process was carried out, ie experimentally
and numeric simulation
In experiment at laboratorium, The RHTV which used has a 10 mm
diameter and 100 mm long. Inlet air pressure used is varied between 2, 3, 4 and 5
bar and amount of nozzles mounted on RHTV varies ie 2, 3 and 4 nozzle
(where the total of cross-sectional area of nozzle used created equal). Whereas
in the process of numerical simulations, which use CFD software Numeca Fine
7.3 with K-ε turbulence model, from numerical simulation results used to compare
experimental results RHTV using 3 and 4 nozzles at a pressure of 5 bar and on
cold fraction around 48.1% which is then analyzed to see the nature of the
distribution of air in the RHTV
Experimental results on cold fraction between 20% to 90% and at various
pressures, RHTV with 3 nozzles generally has lower performance than RHTV
with 2 and 4 nozzles, while RHTV the nozzle 4 has better performance than
RHTV the nozzle 2. On the pressure of 5 bars, RHTV with 2 or 4 nozzles have the
same relative performance
In general, the influence of variation inlet pressure which used on
relationship of ï��Tc and ï�¨v toward an increase ï�c on each RHTV will increase
when the inlet pressure increased as well..
The results of numerical simulation shows the temperature distribution in
axial directions of RHTV increased towards the end hot sectiont, but for section of
cold end the temperatur decline occurs. The results also show the phenomenon
of the compression process in RHTV both radially in the tube cross section and
axially toward hot end section, while toward of cold end section the expansion
process occurs. Another resulsts shows, that the temperature and pressure
distribution on RHTV with 4 nozzles are lower than RHTV with 3 nozzles, this
agrees with the experimental results.
|
|---|