scholarly journals THE EFFECT OF BEND ANGLE ON THE EVAPORATIVE COOLING OF AIR FLOW THROUGH BENT DUCT

2021 ◽  
Vol 21 (4) ◽  
pp. 240-258
Author(s):  
Abdul Sattar Jawad Mohammed ◽  
Akeel Asie Nazzal
Keyword(s):  
Flow Direction ◽  
Evaporative Cooling ◽  
Water Injection ◽  
Axial Flow ◽  
Bend Angle ◽  
Air Velocity ◽  
Square Duct ◽  
Compressor Inlet ◽  
Flow Through ◽  
Bend Angles

One remediation to output power drop of a gas turbine generating units during hot climates is reducing compressor inlet air temperature using fogging technique incorporating water injection into the airstream. The inlet air ductworks often include a bend or curved duct before the compressor comprising the secondary flow utilized to enhance the mixing between air and water droplets. This study investigates the effect of changing the bend angle on the resultant evaporative cooling of steadily flowing airstream. The experiments were conducted with an average air velocity range from (2.5 to 5 m/s) through (50) cm square duct. The study considered three bend angles of (45°, 90° and 135°) along with three sets of nozzle tilt angles of (- 45o, 0° and 45° ) to the axial flow direction. The results reveal that best evaporative cooling was achieved at a bend angle of (135°) when the water is axially injected, i.e., at (0o) to flow direction. These conditions were obtained at the velocity of (2.5 m/s), giving enough residence time for the injected droplets to evaporate and cool the airstream.

An Evaluation of the Effects of Water Injection on Compressor Performance

2003 ◽  
Author(s):  
A. J. White ◽  
A. J. Meacock
Keyword(s):  
Gas Turbines ◽  
Evaporative Cooling ◽  
Water Injection ◽  
Compression Process ◽  
Compressor Inlet ◽  
Design Behaviour ◽  
Industrial Gas Turbines ◽  
Compressor Performance ◽  
Compressor Work ◽  
The Impact

The injection of water droplets into compressor inlet ducting is now commonly used as a means of boosting the output from industrial gas turbines. The chief mechanisms responsible for the increase in power are the reduction in compressor work per unit flow and the increase in mass flow rate, both of which are achieved by evaporative cooling upstream of and within the compressor. This paper examines the impact of such evaporative processes on compressor operation, focussing particular attention on cases with substantial over-spray — i.e., for which significant evaporation takes place within the compressor itself, rather than in the inlet. A simple numerical method is described for the computation of wet compression processes, based on a combination of droplet evaporation and mean-line calculations. The method is applied to a “generic” compressor geometry in order to investigate the nature of the off-design behaviour that results from evaporative cooling. Consideration is also given to the efficiency of the compression process, the implications for choking and stall, and the magnitude of the thermodynamic loss resulting from irreversible phase change.

An Evaluation of the Effects of Water Injection on Compressor Performance

2004 ◽  
Vol 126 (4) ◽  
pp. 748-754 ◽  
Author(s):  
A. J. White ◽  
A. J. Meacock
Keyword(s):  
Gas Turbines ◽  
Evaporative Cooling ◽  
Water Injection ◽  
Droplet Evaporation ◽  
Compression Process ◽  
Compressor Inlet ◽  
Industrial Gas Turbines ◽  
Compressor Performance ◽  
Compressor Work ◽  
The Impact

The injection of water droplets into compressor inlet ducting is now commonly used as a means of boosting the output from industrial gas turbines. The chief mechanisms responsible for the increase in power are the reduction in compressor work per unit flow and the increase in mass flow rate, both of which are achieved by evaporative cooling upstream of and within the compressor. This paper examines the impact of such evaporative processes on compressor operation, focussing particular attention on cases with substantial overspray—i.e., for which significant evaporation takes place within the compressor itself, rather than in the inlet. A simple numerical method is described for the computation of wet compression processes, based on a combination of droplet evaporation and mean-line calculations. The method is applied to a “generic” compressor geometry in order to investigate the nature of the off-design behavior that results from evaporative cooling. Consideration is also given to the efficiency of the compression process, the implications for choking and stall, and the magnitude of the thermodynamic loss resulting from irreversible phase change.

Flow through axial-flow-turbomachinery blading

2018 ◽  
Author(s):  
Marcel Escudier
Keyword(s):  
Flow Velocity ◽  
Compressible Flow ◽  
Dimensional Analysis ◽  
Incompressible Flow ◽  
Compressible Fluid ◽  
Axial Flow ◽  
Linear Cascade ◽  
Dimensional Parameters ◽  
Flow Through

This chapter is concerned primarily with the flow of a compressible fluid through stationary and moving blading, for the most part using the analysis introduced in Chapter 11. The principles of dimensional analysis are applied to determine the appropriate non-dimensional parameters to characterise the performance of a turbomachine. The analysis of incompressible flow through a linear cascade of aerofoil-like blades is followed by the analysis of compressible flow. Velocity triangles for flow relative to blades, and Euler’s turbomachinery equation, are introduced to analyse flow through a rotor. The concepts introduced are applied to the analysis of an axial-turbomachine stage comprising a stator and a rotor, which applies to either a compressor or a turbine.

Effect of structural deformations and bend angle on the collapse load of pipe bends subjected to in-plane closing bending moment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Silambarasan R. ◽  
Veerappan A.R. ◽  
Shanmugam S.
Keyword(s):  
Plastic Material ◽  
Large Strain ◽  
Bending Moment ◽  
Bend Angle ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Content Type ◽  
Structural Deformations ◽  
Bend Angles

Purpose The purpose of this study is to investigate the effect of structural deformations and bend angle on plastic collapse load of pipe bends under an in-plane closing bending moment (IPCM). A large strain formulation of three-dimensional non-linear finite element analysis was performed using an elastic perfectly plastic material. A unified mathematical solution was proposed to estimate the collapse load of pipe bends subjected to IPCM for the considered range of bend characteristics. Design/methodology/approach ABAQUS was used to create one half of the pipe bend model due to its symmetry on the longitudinal axis. Structural deformations, i.e. ovality (Co) and thinning (Ct) varied from 0% to 20% in 5% steps while the bend angle (ø) varied from 30° to 180° in steps of 30°. Findings The plastic collapse load decreases as the bend angle increase for all pipe bend models. A remarkable effect on the collapse load was observed for bend angles between 30° and 120° beyond which a decline was noticed. Ovality had a significant effect on the collapse load with this effect decreasing as the bend angle increased. The combined effect of thinning and bend angle was minimal for the considered models and the maximum per cent variation in collapse load was 5.76% for small bend angles and bend radius pipe bends and less than 2% for other cases. Originality/value The effect of structural deformations and bend angle on collapse load of pipe bends exposed to IPCM has been not studied in the existing literature.

Performance prediction of axial flow compressors using stage characteristics and simultaneous calculation of interstage parameters

2001 ◽  
Vol 215 (1) ◽  
pp. 89-98 ◽  
Author(s):  
T. W. Song ◽  
T. S. Kim ◽  
J. H. Kim ◽  
S. T. Ro
Keyword(s):  
Gas Turbine ◽  
System Analysis ◽  
Axial Flow ◽  
Performance Estimation ◽  
Predicting Performance ◽  
Functional Formulation ◽  
Compressor Inlet ◽  
Multistage Compressors ◽  
And Performance ◽  
Axial Flow Compressors

A new method for predicting performance of multistage axial flow compressors is proposed that utilizes stage performance curves. The method differs from the conventional sequential stage-stacking method in that it employs simultaneous calculation of all interstage variables (temperature, pressure and flow velocity). A consistent functional formulation of governing equations enables this simultaneous calculation. The method is found to be effective, i.e. fast and stable, in obtaining solutions for compressor inlet and outlet boundary conditions encountered in gas turbine analyses. Another advantage of the method is that the effect of changing the angles of movable stator vanes on the compressor's operating behaviour can be simulated easily. Accordingly, the proposed method is very suitable for complicated gas turbine system analysis. This paper presents the methodology and performance estimation results for various multistage compressors employing both fixed and variable vane setting angles. The effect of interstage air bleeding on compressor performance is also demonstrated.

Numerical Study on the Effect of Bend Angle on Turbulent Flow through Oscillating Bend

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Elham Ameri ◽  
M Nasr Esfahany
Keyword(s):  
Numerical Study ◽  
Bend Angle ◽  
Curvature Radius ◽  
Primary Flow ◽  
Mean Velocity ◽  
Contour Map ◽  
Curved Pipes ◽  
Flow Through ◽  
The Mean ◽  
Turbulent Air Flow

The effect of the bend angle on the unsteady developing turbulent air flow through oscillating circular-sectioned curved pipes with the various angles of 180°, 135° and 90° was investigated numerically. The bends had a diameter of 106 mm and a curvature radius ratio of 6.0 with long, straight upstream and downstream sections. Results of the mean velocity and static pressure were obtained at a Reynolds number of 31200 and at various longitudinal stations. The velocity of the primary flow was illustrated in the form of contour map and vector diagram. From the inlet plane of the three oscillating bends to the angle of 45°, the velocity fields in 180°, 90° and 135° bends are similar. The high velocity regions, however, occur near the upper and lower parts in 90° and 180° bends, respectively.

scholarly journals Assessment of Mercury-Polluted Soils Adjacent to an Old Mercury-Fulminate Production Plant

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
M. Camps Arbestain ◽  
L. Rodríguez-Lado ◽  
M. Bao ◽  
F. Macías
Keyword(s):  
Surface Waters ◽  
Contaminated Soils ◽  
Flow Direction ◽  
Surface Flow ◽  
Mercury Contamination ◽  
Production Plant ◽  
Polluted Soils ◽  
Flow Through ◽  
Contamination Of Soils ◽  
Surrounding Soil

Mercury contamination of soils and vegetation close to an abandoned Hg-fulminate production plant was investigated. Maximum concentrations of Hg (>6.5 gkg−1soil) were found in the soils located in the area where the wastewater produced during the washing procedures carried out at the production plant used to be discharged. A few meters away from the discharge area, Hg concentrations decreased to levels ranging between 1 and 5 gkg−1, whereas about 0.5 ha of the surrounding soil to the NE (following the dominant surface flow direction) contained between 0.1 and 1 gkg−1. Mercury contamination of soils was attributed (in addition to spills from Hg containers) to (i) Hg volatilization with subsequent condensation in cooler areas of the production plant and in the surrounding forest stands, and (ii) movement of water either by lateral subsurface flow through the contaminated soils or by heavy runoff to surface waters.

Effect of Bend Angle on Gross Plastic Deformation of Pipe Bends: A Finite Element Based Study

2015 ◽  
Author(s):  
Anindya Bhattacharya ◽  
Sachin Bapat ◽  
Hardik Patel ◽  
Shailan Patel
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Failure Mechanisms ◽  
Bending Moment ◽  
Bend Angle ◽  
Piping System ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Bend Angles

Bends are an integral part of a piping system. Because of the ability to ovalize and warp they offer more flexibility when compared to straight pipes. Piping Code ASME B31.3 [1] provides flexibility factors and stress intensification factors for the pipe bends. Like any other piping component, one of the failure mechanisms of a pipe bend is gross plastic deformation. In this paper, plastic collapse load of pipe bends have been analyzed for various bend parameters (bend parameter = tRbrm2) under internal pressure and in-plane bending moment for various bend angles using both small and large deformation theories. FE code ABAQUS version 6.9EF-1 has been used for the analyses.

scholarly journals Development of Inlet for an Axial Compressor

1968 ◽  
Author(s):  
R. C. Reisweber
Keyword(s):  
Axial Compressor ◽  
Axial Flow ◽  
Test Program ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Compressor Inlet ◽  
Three Stages ◽  
Overall Performance

In development of an axial-flow boiler supercharger, a test program on the compressor inlet was carried out. Tests were run using a test compressor aerodynamically identical to the first three stages of the supercharger compressor. Prototype compressor inlet was compared to an axial inlet, and also to several modified inlets. While the prototype inlet showed considerably more distortion ahead of the inlet guide vanes than the axial inlet, the inlet guide vanes removed most of the distortion. As a result, overall performance of all inlet configurations was essentially the same.

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