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Jain, Parveen Kumar 2014-12-14T06:26:17Z 2014-12-14T06:26:17Z 10000-01-01 1981 1981 An experimental investigation of the statistical character of boiling flows has been carried out. Two vertical, concentric annular test sections were used. Two flow-field variables, viz. static pressure fluctuations at the test section outer wall and instantaneous chordal-average vapor fraction, were studied. Matched piezo-electric pressure transducers were used for the pressure fluctuation measurements, and a linearized dual-beam x-ray system was used for the vapor fraction measurements. Steady state (mean) thermal-hydraulic condition in the last section was determined by an analytical model and verified to a certain extent by capacitance probe vapor volume fraction measurements. A wide range of local (measurement station) vapor fraction conditions with prevalent flow regimes ranging from subcooled bubbly to saturated churn turbulent-slug-annular was investigated. The wall static pressure fluctuation results include: (i) intensity (RMS value), (ii) probability density functions, and (iii) auto-power spectral density functions. The instantaneous chordal-average vapor fraction results include: (i) probability density functions, and (ii) auto-power spectral density functions. Coherence functions between the wall pressure fluctuations and the vapor fraction fluctuations are presented as well. A preliminary effort towards numerical simulation of vapor fraction fluctuations is reported. It is suggested that diagnosis of boiling flow regimes on the basis of the statistical properties of wall static pressure fluctuations and vapor fraction fluctuations may be possible. Made available in DSpace on 2014-12-14T06:26:17Z (GMT). No. of bitstreams: 1 8127612.pdf: 4602609 bytes, checksum: 81cd17ca3409d39d9419692cb7ce3353 (MD5) Previous issue date: 1981 Embargo set by: Seth Robbins for item 67976 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 160 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981. http://hdl.handle.net/2142/67798 (UMI)AAI8127612 eng Engineering, Nuclear On the Statistical Nature of Boiling Flows - an Experimental Approach text Nuclear Engineering Nuclear Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.