A Theoretical Study of the Performance of an Axial Flow Turbine for a Microhydro Installation

1996 ◽  
Vol 210 (2) ◽  
pp. 121-129 ◽  
Author(s):  
G J Parker
Keyword(s):  
Theoretical Study ◽  
Draft Tube ◽  
Guide Vane ◽  
Turbine Blades ◽  
Axial Flow ◽  
Prototype System ◽  
Blade Angle ◽  
Flow Through ◽  
Loss Coefficients ◽  
Vane Angle

The Bernoulli-with-loss equation, with the losses represented by a constant times the velocity head, has been applied to each section of the flow through a small turbine system consisting of inlet guide vanes, axial flow turbine and draft tube. Using experimental data and the sets of equations, the flow angles around the turbine blades and the loss coefficients in the turbine and in the draft tube were determined. These were used to predict the effect of varying the guide vane angle and the turbine blade angle on performance. They were also used to predict the effects on the performance of a geometrically similar prototype system.

Interactional Effects of Inlet Guide Vane and Blade Angle on Hydraulic Performance Characteristics of a Submersible Axial-Flow Pump

2018 ◽  
Author(s):  
Youn-Sung Kim ◽  
Hyeon-Seok Shim ◽  
Kwang-Yong Kim
Keyword(s):  
Stokes Equations ◽  
Guide Vane ◽  
Incidence Angle ◽  
Axial Flow ◽  
Performance Characteristics ◽  
Inlet Guide Vane ◽  
Computational Domain ◽  
Blade Angle ◽  
Axial Flow Pump ◽  
Flow Pump

This study aims to evaluate effects of blade pitch and inlet guide vane (IGV) angle on the performance characteristics of a submersible axial-flow pump. According to the results of the previous study, the efficiency at the design and over-load conditions were significantly affected by the angle of IGV due to change in the incidence angle. To investigate the interactional effects of IGV and blade angle are analyzed using three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model. The hexahedral grids are used in the computational domain and a grid-dependency test is performed to obtain an optimal number of the grids. In this study, combinations of three different blade angles and two different IGV angles are tested. Adjusting angle of IGV increases the total pressure of the pump with a blade pitch increase, which can increase the efficiency of the pump in operating range.

Performance Study of a 1 MW Gas Turbine Using Variable Geometry Compressor and Turbine Blade Cooling

2010 ◽  
Author(s):  
Cleverson Bringhenti ◽  
Jesuino Takachi Tomita ◽  
Joa˜o Roberto Barbosa
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Turbine Blades ◽  
Axial Flow ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Performance Study ◽  
Turbine Blade Cooling ◽  
Blade Cooling

This work presents the performance study of a 1 MW gas turbine including the effects of blade cooling and compressor variable geometry. The axial flow compressor, with Variable Inlet Guide Vane (VIGV), was designed for this application and its performance maps synthesized using own high technological contents computer programs. The performance study was performed using a specially developed computer program, which is able to numerically simulate gas turbine engines performance with high confidence, in all possible operating conditions. The effects of turbine blades cooling were calculated for different turbine inlet temperatures (TIT) and the influence of the amount of compressor-bled cooling air was studied, aiming at efficiency maximization, for a specified blade life and cooling technology. Details of compressor maps generation, cycle analysis and blade cooling are discussed.

Development of a Cost-Efficient Test Rig for Turbine Loss Education

2014 ◽  
Author(s):  
Stefan aus der Wiesche ◽  
Steffen Wulff ◽  
Felix Reinker ◽  
Karsten Hasselmann
Keyword(s):  
Turbine Blades ◽  
Test Rig ◽  
Flow Angle ◽  
Efficient Test ◽  
Academic Courses ◽  
Flow Deviation ◽  
Flow Through ◽  
Loss Coefficients ◽  
Turbine Cascades ◽  
Cost Efficient

A large number of approaches have been made to predict the total pressure loss coefficients and flow deviation angles to the geometry of turbine cascades and the incoming flow. Students feel typically uncomfortable when faced with turbine loss coefficients during their education, and it is challenging to fully understand turbine losses only by means of theory. The integration of a turbine cascade facility into academic courses might be useful but such test facilities are expensive or not available for a large number of engineering schools. To overcome this issue, a cost-efficient test rig for measurements of the flow through a two-dimensional cascade of turbine blades was designed. This test rig enabled the measurement of the flow through a blade cascade and the formation of wakes. The effect of the inlet flow angle on the cascade performance was investigated easily by students. Based on own measurements, the students were able to apply the most prominent approaches for determining loss coefficients. Furthermore, they compared their results with literature data and predictions of available correlations. By doing that, the importance of blade spacing and Reynolds number level on profile loss coefficients became more transparent and invited to further studies.

The Use of Circumferentially Varying Stagger Guide Vanes in an Axial Flow Pump or Compressor

1990 ◽  
Vol 112 (2) ◽  
pp. 294-297 ◽  
Author(s):  
J. H. Horlock
Keyword(s):  
Total Pressure ◽  
Guide Vane ◽  
Axial Flow ◽  
Guide Vanes ◽  
Actuator Disk ◽  
Outlet Angle ◽  
Flow Through ◽  
Axial Flow Pump ◽  
Flow Pump

An actuator disk analysis is given of the flow through a guide vane and rotor combination. It is shown that changes in total pressure across the rotor are in general related to circumferential variations in guide vane outlet angle. In particular known variations in inlet total pressure may be eliminated by suitable circumferential changes in guide vane stagger.

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.

scholarly journals Mathematical study on two-fluid model for flow of K–L fluid in a stenosed artery with porous wall

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
R. Ponalagusamy ◽  
Ramakrishna Manchi
Keyword(s):  
Theoretical Study ◽  
Fluid Model ◽  
Porous Wall ◽  
Governing Equations ◽  
Rate Of Increase ◽  
Special Cases ◽  
Stenosed Artery ◽  
Flow Through ◽  
Two Fluid Model ◽  
Two Fluid

AbstractThe present communication presents a theoretical study of blood flow through a stenotic artery with a porous wall comprising Brinkman and Darcy layers. The governing equations describing the flow subjected to the boundary conditions have been solved analytically under the low Reynolds number and mild stenosis assumptions. Some special cases of the problem are also presented mathematically. The significant effects of the rheology of blood and porous wall of the artery on physiological flow quantities have been investigated. The results reveal that the wall shear stress at the stenotic throat increases dramatically for the thinner porous wall (i.e. smaller values of the Brinkman and Darcy regions) and the rate of increase is found to be 18.46% while it decreases for the thicker porous wall (i.e. higher values of the Brinkman and Darcy regions) and the rate of decrease is found to be 10.21%. Further, the streamline pattern in the stenotic region has been plotted and discussed.

Validating Numerical CFD Simulations With Experimental Data for Turbulence Phenomena in Axial Flow Gas Turbine Diffusers

2009 ◽  
Author(s):  
Farrokh Zarifi-Rad ◽  
Hamid Vajihollahi ◽  
James O’Brien
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Axial Flow ◽  
Experimental Results ◽  
Scale Model ◽  
Data Set ◽  
Pressure Profiles ◽  
Scale Models ◽  
Inlet Conditions

Scale models give engineers an excellent understanding of the aerodynamic behavior behind their design; nevertheless, scale models are time consuming and expensive. Therefore computer simulations such as Computational Fluid Dynamics (CFD) are an excellent alternative to scale models. One must ask the question, how close are the CFD results to the actual fluid behavior of the scale model? In order to answer this question the engineering team investigated the performance of a large industrial Gas Turbine (GT) exhaust diffuser scale model with performance predicted by commercially available CFD software. The experimental results were obtained from a 1:12 scale model of a GT exhaust diffuser with a fixed row of blades to simulate the swirl generated by the last row of turbine blades five blade configurations. This work is to validate the effect of the turbulent inlet conditions on an axial diffuser, both on the experimental front and on the numerical analysis approach. The object of this work is to bring forward a better understanding of velocity and static pressure profiles along the gas turbine diffusers and to provide an accurate experimental data set to validate the CFD prediction. For the CFD aspect, ANSYS CFX software was chosen as the solver. Two different types of mesh (hexagonal and tetrahedral) will be compared to the experimental results. It is understood that hexagonal (HEX) meshes are more time consuming and more computationally demanding, they are less prone to mesh sensitivity and have the tendancy to converge at a faster rate than the tetrahedral (TET) mesh. It was found that the HEX mesh was able to generate more consistent results and had less error than TET mesh.

Influence of Leading Edge Fillet and Nonaxisymmetric Contoured Endwall on Turbine NGV Exit Flow Structure and Interactions With the Rim Seal Flow

2013 ◽  
Author(s):  
Özhan H. Turgut ◽  
Cengiz Camcı
Keyword(s):  
Flow Structure ◽  
Total Pressure ◽  
Guide Vane ◽  
Axial Flow ◽  
Leading Edge ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Constant Thickness ◽  
Computational Evaluation ◽  
Nozzle Guide

Three different ways are employed in the present paper to reduce the secondary flow related total pressure loss. These are nonaxisymmetric endwall contouring, leading edge (LE) fillet, and the combination of these two approaches. Experimental investigation and computational simulations are applied for the performance assessments. The experiments are carried out in the Axial Flow Turbine Research Facility (AFTRF) having a diameter of 91.66cm. The NGV exit flow structure was examined under the influence of a 29 bladed high pressure turbine rotor assembly operating at 1300 rpm. For the experimental measurement comparison, a reference Flat Insert endwall is installed in the nozzle guide vane (NGV) passage. It has a constant thickness with a cylindrical surface and is manufactured by a stereolithography (SLA) method. Four different LE fillets are designed, and they are attached to both cylindrical Flat Insert and the contoured endwall. Total pressure measurements are taken at rotor inlet plane with Kiel probe. The probe traversing is completed with one vane pitch and from 8% to 38% span. For one of the designs, area averaged loss is reduced by 15.06%. The simulation estimated this reduction as 7.11%. Computational evaluation is performed with the rotating domain and the rim seal flow between the NGV and the rotor blades. The most effective design reduced the mass averaged loss by 1.28% over the whole passage at the NGV exit.

Development of a New Front Stage for an Industrial Axial Flow Compressor

1994 ◽  
Vol 116 (4) ◽  
pp. 597-604 ◽  
Author(s):  
B. Eisenberg
Keyword(s):  
Design Method ◽  
Guide Vane ◽  
Theoretical Calculations ◽  
Axial Flow ◽  
Operating Range ◽  
Performance Curves ◽  
Front Stage ◽  
Inverse Design Method ◽  
Flow Compressor ◽  
High Degree

Industrial axial flow compressors are specially designed to achieve a wide operating range. The analysis of an existing six-stage axial flow research compressor indicated that the front stage could be improved significantly using modern design technique. To demonstrate the advantages of such a technique a redesign of the current front stage was conducted. By controlling the diffusion inside the blade sections with an inverse design method, loading was enlarged. Higher loading normally results in a reduction of profile incidence range. For compensation a wide chord application was chosen. Compared to the original compressor version, experiments resulted in steeper characteristic curves together with larger usable operating range. Keeping the same outer and inner diameter, mass flow was increased by 6 percent. Measurements of performance curves with variable speed and for guide vane control are presented. Theoretical calculations achieve a high degree of agreement with measured performance.

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