Analytical investigation into simultaneous effects of friction and heating on a supersonic nucleating Laval nozzle

In supersonic water vapor ow of low pressure turbines, nucleation phenomena and consequent condensation are commonly observed. Internal heat transfer, which is caused by phase change, is strongly irreversible and has unwanted effects on turbine efficiency. The strike of formed droplets on the surfac...

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Bibliographic Details
Published inScientia Iranica. Transaction B, Mechanical engineering Vol. 21; no. 5; p. 1700
Main Authors Mahpeykara, M R, Rad, E Amiri, Teymourtash, A R
Format Journal Article
LanguageEnglish
Published Tehran Sharif University of Technology 01.10.2014
Subjects
Aerodynamics
Condensation
Friction
Heat transfer
Mechanical engineering
Turbines
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Summary:In supersonic water vapor ow of low pressure turbines, nucleation phenomena and consequent condensation are commonly observed. Internal heat transfer, which is caused by phase change, is strongly irreversible and has unwanted effects on turbine efficiency. The strike of formed droplets on the surfaces results in large amounts of mechanical damage. Condensation heat release to supersonic ow, named condensation shock, leads to considerable pressure rise, which, in turn, reduces outlet velocity and occasionally causes severe oscillations, making the ow supercritical. In this paper, and in continuation of the series of papers by the same authors, one dimensional, supersonic and two-phase flow is modeled analytically, and the simultaneous effects of volumetric heat transfer and friction in the convergent nozzle are investigated. It is concluded that the simultaneous use of a friction and a volumetric heating can be an appropriate and useful technique for the control of two-phase flow conditions, keeping them within the desired range.