Effect of the viscosity of the liquid phase on the true gas content and the region of stratified flow of a two-phase mixture in slightly inclined pipes

1983 ◽  
Vol 45 (2) ◽  
pp. 865-868
Author(s):  
A. A. Tochigin ◽  
N. N. Elin ◽  
V. G. Arsenov
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. The liquid phase consists of a large number of extremely small droplets which are difficult to generate except by nucleation. To reproduce turbine two-phase flow conditions requires a supply of supercooled vapour which can be achieved under blow-down conditions by the equipment employed. This paper is the third of a set describing an investigation into the performance of a cascade of rotor tip section profiles in wet steam and presents the results of the wake traverses.


Lab on a Chip ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 2154-2165
Author(s):  
Yuexiao Song ◽  
Feng Xin ◽  
Yongsheng Xu

Liquid phase catalytic exchange of hydrogen isotopes is intensified by stratified flow in a microchannel reactor coated with hydrophobic Pt/AC/PDMS.


Author(s):  
F Bakhtar ◽  
M Y Zamri

This article is the last of a set and describes the analysis of the performance of an improved steam turbine nozzle blade profile. In the course of expansion of steam in turbines, the state path crosses the saturation line, the fluid nucleates to become wet, and the succeeding stages have to operate on a two-phase mixture. The formation and subsequent behaviour of the liquid phase lowers the performance of turbine wet stages. Following earlier studies of typical profiles in nucleating steam, the performance of a new design of blades is examined. A substantially improved aerodynamic performance is achieved by the new design. The effect of heat release by condensation in increasing the aerodynamic losses is not intrinsic to the system and can be avoided by design but the losses resulting from the internal heat transfer are intrinsic and considerable.


Author(s):  
F Bakhtar ◽  
Z A Mamat ◽  
O C Jadayel

This article is the second of a set and describes the results of wake traverses and droplet measurements in a cascade of steam turbine improved nozzle blade profiles. In the course of expansion of steam in turbines the state path crosses the saturation line, the fluid nucleates become wet, and the succeeding stages have to operate on a two-phase mixture. The formation and subsequent behaviour of the liquid phase lowers the performance of turbine wet stages. To study these problems systematically the turbine two-phase flow conditions need to be reproduced realistically, which can be done under blow down conditions. Following earlier studies of typical profiles in nucleating steam the performance of a new design of blades is presented. A substantially improved aerodynamic performance is achieved by the new profile.


Author(s):  
N. A. Bulychev

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.


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