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Aristotle University Of Thessaloniki (AUTH)

ΜΕΛΕΤΗ ΔΑΚΤΥΛΙΟΕΙΔΟΥΣ ΔΙΦΑΣΙΚΗΣ ΡΟΗΣ ΣΕ ΟΡΙΖΟΝΤΙΟ ΑΓΩΓΟ

Abstract

dc:description

TIME RECORDS HAVE BEEN COLLECTED OF LOCAL LIQUID FILM THICKNESS, USING PARALLELWIRE CONDUCTANCE PROBES, IN A NEW 50.8 MM I.D. PIPE LOOP. STATISTICAL ANALYSISOF THESE RECORDS ALLOWS THE STUDY OF CIRCUMFERENTIAL VARIATION OF TIME-AVERAGED THICKNESS AND OF OTHER QUANTITIES. THE POWER SPECTRA SHOW THAT THE DOMINANT FREQUENCY ASSOCIATED WITH LARGE WAVES IS <10 HZ AT LOW GAS VELOCITIES, DISPLAYING A TENDENCY TO INCREASE WITH GAS FLOW RATE. BY COMBINING SIGNAL CROSS-CORRELATION DATA WITH VISUAL OBSERVATIONS, IT IS SHOWN THAT THE DISTURBANCE WAVES TEND TO DEFORM RAPIDLY, MOVE ON A PLANE INCLINED WITH RESPECT TO THE VERTICAL, AND COVER AN INCREASINGLY LARGER PORTION OF THE CIRCUMFERENCE WITH INCREASING GAS VELOCITY. THE MEAN LARGE WAVE HEIGHT AT THE PIPE BOTTOM IS LINEARLY RELATED TO THE LOCAL RMS VALUE. IT IS ALSO A STRONG FUNCTION OF GAS FLOW RATE, WITH A MODERATE DEPENDENCE ON LIQUID FLOW RATE. HOWEVER, THE DISTURBANCE WAVE INTERMITTENCY APPEARS TO BE ALMOST INDEPENDENT OF GAS AS WELL AS LIQUID FLOW RATES. (SHORTENED)

Degree

thesis:*
Grantor dc:publisher
Aristotle University Of Thessaloniki (AUTH)
Year dc:date
1991

Author and committee

dc:creator, dc:contributor.*
Authors dc:creator
  • Παράς, Σπυρίδων
  • Paras, Spyridon

Subjects

dc:subject × 24

Rights

Language dc:language
gre

Identifiers

dc:identifier.*
Identifier
10.12681/eadd/1708
OAI identifier oai:identifier
oai:10442/1708

Chain of custody

source
Harvested from
Greek National Archive of PhD Theses
Base URL
phdtheses.ekt.gr/eadd_oai/request
Last updated
2026-07-24
Source record
OAI-PMH GetRecord
citation

Παράς, Σπυρίδων; Paras, Spyridon. ΜΕΛΕΤΗ ΔΑΚΤΥΛΙΟΕΙΔΟΥΣ ΔΙΦΑΣΙΚΗΣ ΡΟΗΣ ΣΕ ΟΡΙΖΟΝΤΙΟ ΑΓΩΓΟ. Aristotle University Of Thessaloniki (AUTH), 1991. http://hdl.handle.net/10442/hedi/1708