On the performance of a cascade of turbine rotor tip section blading in wet steam Part 3: Wake traverses

1997 ◽  
Vol 211 (8) ◽  
pp. 639-648 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
The Third ◽  
Phase Mixture

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.

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 1: Generation of wet steam of prescribed droplet sizes

1997 ◽  
Vol 211 (7) ◽  
pp. 519-529 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
J R Buckley
Keyword(s):  
Superheated Steam ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Lower Efficiency ◽  
Blow Down ◽  
Droplet Sizes ◽  
Phase Mixture

During the course of expansion in turbines steam nucleates to become a two-phase mixture consisting of a very large number of extremely small droplets carried by the vapour. Turbine stages operating in a two-phase regime have a lower efficiency than those working on superheated steam. To reproduce turbine two-phase flow conditions realistically requires a supply of supercooled steam which can be generated under blow-down conditions by the equipment employed. To generate wet steam the supercooled steam can be passed through a venturi. This paper is one of a set describing an investigation of the performance of a cascade of turbine rotor tip section profiles in wet steam and is concerned with the generation of a supply of wet steam of prescribed droplet sizes for admission to the cascade.

On the Performance of a Cascade of Turbine Rotor Tip Section Blading in Nucleating Steam: Part 2: Wake Traverses

1995 ◽  
Vol 209 (3) ◽  
pp. 169-177 ◽  
Author(s):  
F Bakhtar ◽  
M Ebrahimi ◽  
B O Bamkole
Keyword(s):  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
Phase Mixture

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. 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 second of a set describing an investigation into the performance of a cascade of rotor tip section profiles in nucleating steam and presents the results of the wake traverses and droplet measurements.

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 2: Surface pressure distributions

1997 ◽  
Vol 211 (7) ◽  
pp. 531-540 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Droplet Size ◽  
Surface Pressure ◽  
Turbine Rotor ◽  
Pressure Measurements ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
Pressure Distributions ◽  
Phase Mixture

In the course of expansion in turbines steam nucleates to become a two-phase mixture, the liquid consisting of a very large number of extremely small droplets carried by the vapour. Formation and subsequent behaviour of the liquid lowers the performance of turbine wet stages. To produce turbine nucleating and wet flow conditions realistically requires a supply of supercooled steam which can be achieved under blow-down conditions by the equipment employed. To obtain wet steam, the supercooled vapour generated is passed through a venturi before admission to the cascade. To evaluate the influence of droplet size two separate Venturis have been used in the investigation. The performance of a cascade of rotor tip section blading in wet steam has been studied. This paper is the second of a set and describes the results of the surface pressure measurements.

An Investigation of Nucleating Flows of Stream in a Cascade of Turbine Blading—Wake Traverses

1994 ◽  
Vol 116 (1) ◽  
pp. 121-127 ◽  
Author(s):  
F. Bakhtar ◽  
M. Ebrahimi ◽  
R. A. Webb
Keyword(s):  
Short Duration ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
Phase Mixture ◽  
Turbine Blading

During the course of expansion in turbines, steam first supercools and then nucleates to become a two-phase mixture consisting of a very large number of minute droplets suspended in the parent vapor. To reproduce turbine two-phase flow conditions realistically requires a supply of supercooled vapor, which can be achieved under blow-down conditions. This paper is one of a set describing the equipment which has been constructed and the first family of results obtained on a short duration cascade tunnel working on the blow-down principle. The arrangements for traversing downstream of a cascade of nozzle blades and the results obtained are described in the paper.

On the performance of a cascade of improved turbine nozzle blades in nucleating steam. Part 2: Wake traverses

2009 ◽  
Vol 223 (8) ◽  
pp. 1915-1929 ◽  
Author(s):  
F Bakhtar ◽  
Z A Mamat ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Steam Turbine ◽  
Aerodynamic Performance ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
Phase Mixture ◽  
State Path ◽  
Nozzle Blade

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.

On the Performance of a Cascade of Turbine Rotor Tip Section Blading in Nucleating Steam: Part 1: Surface Pressure Distributions

1995 ◽  
Vol 209 (2) ◽  
pp. 115-124 ◽  
Author(s):  
F Bakhtar ◽  
M Ebrahimi ◽  
R A Webb
Keyword(s):  
Surface Pressure ◽  
Turbine Rotor ◽  
Pressure Measurements ◽  
Flow Conditions ◽  
Mixture Formation ◽  
Two Phase ◽  
Blow Down ◽  
Pressure Distributions ◽  
Phase Mixture

During the course of expansion in turbines, steam first supercools and then nucleates to become a two-phase mixture. Formation and subsequent behaviour of the liquid lower the performance of turbine wet stages. To reproduce turbine nucleating and wet flow conditions requires a supply of supercooled steam which can be achieved under blow-down conditions by the equipment employed. The performance of a cascade of rotor tip section blading in nucleating steam has been studied. The results of the surface pressure measurements are described in the paper.

Simulation of Two Phase Flow Dynamics in Flexible Riser Exit Geometries for Oil and Gas Applications

2018 ◽  
Vol 39 ◽  
pp. 1-13
Author(s):  
Ikpe E. Aniekan ◽  
Owunna Ikechukwu ◽  
Satope Paul
Keyword(s):  
Oil And Gas ◽  
Two Phase Flow ◽  
Flow Analysis ◽  
Computational Cost ◽  
Maximum Velocity ◽  
Oil Well ◽  
Phase Flow ◽  
Two Phase ◽  
The Third ◽  
Riser Pipe

Four different riser pipe exit configurations were modelled and the flow across them analysed using STAR CCM+ CFD codes. The analysis was limited to exit configurations because of the length to diameter ratio of riser pipes and the limitations of CFD codes available. Two phase flow analysis of the flow through each of the exit configurations was attempted. The various parameters required for detailed study of the flow were computed. The maximum velocity within the pipe in a two phase flow were determined to 3.42 m/s for an 8 (eight) inch riser pipe. After thorough analysis of the two phase flow regime in each of the individual exit configurations, the third and the fourth exit configurations were seen to have flow properties that ensures easy flow within the production system as well as ensure lower computational cost. Convergence (Iterations), total pressure, static pressure, velocity and pressure drop were used as criteria matrix for selecting ideal riser exit geometry, and the third exit geometry was adjudged the ideal exit geometry of all the geometries. The flow in the third riser exit configuration was modelled as a two phase flow. From the results of the two phase flow analysis, it was concluded that the third riser configuration be used in industrial applications to ensure free flow of crude oil and gas from the oil well during oil production.

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