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Journal ArticleDOI

A Simple and Fast Method for Calculating Properties Across a Condensation Shock

04 Apr 2018-Journal of Fluids Engineering-transactions of The Asme (American Society of Mechanical Engineers)-Vol. 140, Iss: 10, pp 104501
About: This article is published in Journal of Fluids Engineering-transactions of The Asme.The article was published on 2018-04-04. It has received None citations till now. The article focuses on the topics: Shock (mechanics) & Condensation.
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Journal ArticleDOI
TL;DR: In this paper, a series of experiments on steam condensation have been made in a Laval nozzle over a variety of starting conditions such that the onset of condensation occurs in the range -40 to 40 C.
Abstract: : A series of experiments on steam condensation have been made in a Laval nozzle over a variety of starting conditions such that the onset of condensation occurs in the range -40 to 40 C. The homogeneous nucleation and growth of the new phase is documented with both static pressure and laser light scattering. Since even at onset the majority of the condensed phase is due to droplet growth the nucleation and growth are coupled and the availability of two measured quantities is helpful in comparing a particular combination of nucleation rate and growth law. For detailed calculations on one of the experiments there is excellent agreement with both measurements throughout the condensation zone and a theoretical calculation using the classical nucleation rate expression due to Volmer and a droplet growth law due to Gyarmathy.

188 citations

Journal ArticleDOI
01 Dec 2005
TL;DR: In this paper, the classical theory of homogeneous nucleation of water droplets from supersaturated vapour and its application in predicting condensation in steam nozzles is discussed.
Abstract: The paper discusses the classical theory of the homogeneous nucleation of water droplets from supersaturated vapour and its application in predicting condensation in steam nozzles. The first part consists of a review of classical nucleation theory, focusing on the many modifications made to the original Becker-Doring theory and providing some new insights into recent developments. It is concluded that the predictive accuracy required for engineering calculations is not yet attainable with a theory derived from first principles. The areas that require most attention relate to the properties of small molecular clusters and the energy transfer processes in the non-isothermal theory. Experiments in converging-diverging nozzles provide the best means for validation at the very high nucleation rates of interest, but measurements of pressure distribution and the Sauter mean droplet radius are insufficient to provide independent checks on the separate theories of nucleation and droplet growth. Nevertheles...

180 citations

Journal ArticleDOI
TL;DR: In this paper, a detailed experimental and theoretical study of non-equilibrium condensing steam flow in a stationary cascade of turbine blades operating transonically is described, and the thermodynamic loss due to irreversible condensation directly from experimental measurements.
Abstract: The paper describes a detailed experimental and theoretical study of non-equilibrium condensing steam flow in a stationary cascade of turbine blades operating transonically. Instrumentation was installed for obtaining colour schlieren photographs of the shock wave structure, the blade surface static pressure distribution, the pitchwise variation of the mean droplet radius downstream of the cascade and the stagnation pressure loss across the cascade. Only one blade profile was tested but a comprehensive set of measurements was acquired covering a wide range of inlet steam conditions and exit Mach numbers. By careful interpretation of the data, it was possible, for the first time, to infer the thermodynamic loss due to irreversible condensation directly from experimental measurements. An elaborate comparison of the experimental data with condensing flow theory was also undertaken using a two-dimensional inviscid time-marching calculation scheme, simulating both steady and unsteady flows. Excellent agreement was obtained throughout and it can be stated with some confidence that the theory and calculation procedures used reproduce accurately all the main features of steady transonic condensing flow in stationary cascades.

131 citations

Journal ArticleDOI
01 Jun 1938
TL;DR: In this paper, the authors describe experiments performed to determine the pressure distribution in a convergent-divergent steam nozzle of rectangular cross-section, and the Wilson line was determined after allowances for the effects of friction had been made.
Abstract: The paper describes experiments performed to determine the pressure distribution in a convergent-divergent steam nozzle of rectangular cross-section. By means of pressure tappings drilled along the axis, it was found that, in the course of its passage through the nozzle, initially superheated steam expanded continuously until condensation commenced, when a sharp rise of pressure (of the order of 1 lb. per sq. in.) occurred. Up to this point the observations were consistent with the predictions of Callendar's equation for the isentropic expansion of superheated and supersaturated steam: the friction loss was small as far as the throat of the nozzle, but in the divergent portion it was of appreciable magnitude.The Wilson line was determined after allowances for the effects of friction had been made. The pressure rise was also investigated in detail and was found to be accompanied by a decrease of velocity and an increase of total heat. At the peak of the rise, where continuous expansion recommenced, the ste...

53 citations

Journal ArticleDOI
TL;DR: In this article, a conservative two-dimensional compressible numerical model for supersonic non-equilibrium spontaneous condensing steam flow based on the classical nucleation theory and the Virial style equation of state was presented.

51 citations