THERMAL SCIENCE
International Scientific Journal
DISCHARGE COEFFICIENT OF SMALL SONIC NOZZLES
ABSTRACT
The purpose of this investigation is to understand flow characteristics in mini/micro sonic nozzles, in order to precisely measure and control miniscule flowrates. Experimental and numerical simulation methods have been used to study critical flow Venturi nozzles. The results show that the nozzle’s size and shape influence gas flow characteristics which leading the boundary layer thickness to change, and then impact on the discharge coefficient. With the diameter of sonic nozzle throat decreasing, the discharge coefficient reduces. The maximum discharge coefficient exits in the condition of the inlet surface radius being double the throat diameter. The longer the diffuser section, the smaller the discharge coefficient becomes. Diffuser angle affects the discharge coefficient slightly.
KEYWORDS
PAPER SUBMITTED: 2013-09-30
PAPER REVISED: 2014-04-10
PAPER ACCEPTED: 2014-07-12
PUBLISHED ONLINE: 2015-01-04
THERMAL SCIENCE YEAR
2014, VOLUME
18, ISSUE
Issue 5, PAGES [1505 - 1510]
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