scholarly journals Investigation of methods for equalizing the flow parameters in the axial compressor intake flare

2020 ◽  
Vol 21 (6) ◽  
pp. 72-83
Author(s):  
A. E. Zaryankin ◽  
T. Padashmoghanlo ◽  
M. S. Postnikova
Keyword(s):  
Axial Compressor ◽  
Velocity Fields ◽  
Maximum Speed ◽  
Stable Operation ◽  
Average Flow Rate ◽  
Air Inlet ◽  
Flow Parameters ◽  
Compressor Inlet ◽  
Flow Part ◽  
Gas Turbine Compressor

The problem of ensuring a uniform velocity field at the air inlet to the first stage of the gas turbine compressor SGT5-2000E with an angular inlet path, that contains an inlet filter, a silencer and an angular intake flare, is considered. Based on the mathematical modeling of the flow in this flare, it was found that the maximum speed at the compressor inlet is 36% higher than the average flow rate. It leads to the fact that the range of stable operation of the compressor seriously narrows. To solve this problem, it is proposed to change the intake flare design so that a newly developed effective damper of uneven velocity fields is installed in its flow part. Studies have shown that in this way the nonuniformity coefficient was reduced from the above 36% to 6%.

Characteristics of Stable Rotating Stall Cells in an Axial Compressor

2017 ◽  
Author(s):  
Adam R. Hickman ◽  
Scott C. Morris
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Pressure Ratio ◽  
Pressure Sensors ◽  
Axial Compressor ◽  
Field Measurements ◽  
Rotating Stall ◽  
Flow Coefficient ◽  
Stable Operation ◽  
Double Phase

Flow field measurements of a high-speed axial compressor are presented during pre-stall and post-stall conditions. The paper provides an analysis of measurements from a circumferential array of unsteady shroud static pressure sensors during stall cell development. At low-speed, the stall cell approached a stable size in approximately two rotor revolutions. At higher speeds, the stall cell developed within a short amount of time after stall inception, but then fluctuated in circumferential extent as the compressor transiently approached a stable post-stall operating point. The size of the stall cell was found to be related to the annulus average flow coefficient. A discussion of Phase-Locked Average (PLA) statistics on flow field measurements during stable operation is also included. In conditions where rotating stall is present, flow field measurements can be Double Phase-Locked Averaged (DPLA) using a once-per-revolution (1/Rev) pulse and the period of the stall cell. The DPLA method provides greater detail and understanding into the structure of the stall cell. DPLA data indicated that a stalled compressor annulus can be considered to contained three main regions: over-pressurized passages, stalled passages, and recovering passages. Within the over-pressured region, rotor passages exhibited increased blade loading and pressure ratio compared to pre-stall values.

Ported Shroud Flow Processes and Their Effect on Turbocharger Compressor Operation

2017 ◽  
Author(s):  
Sidharath Sharma ◽  
Martyn L. Jupp ◽  
Ambrose K. Nickson ◽  
John M. Allport
Keyword(s):  
Entropy Generation ◽  
Primary Source ◽  
Navier Stokes ◽  
Stable Operation ◽  
Casing Treatment ◽  
Flow Processes ◽  
Compressor Inlet ◽  
Flow Mechanisms ◽  
Sst Turbulence Model ◽  
Ported Shroud

The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of the surge by enhancing the aerodynamic stability of the turbocharger compressor. The increase in the stable operation region of the turbocharger compressor is achieved by recirculating the low momentum fluid that blocks the blade passage to the compressor inlet through a ported shroud cavity. While the ported shroud design delays surge, it comes with a small penalty in efficiency. This work presents an investigation of the flow processes associated with a ported shroud compressor and quantifies the effect of these flow mechanisms on the compressor operation. The full compressor stage is numerically modelled using a Reynolds Averaged Navier-Stokes (RANS) approach employing the shear stress transport (SST) turbulence model for steady state simulations at the design and near surge conditions. The wheel rotation is modelled using a multiple reference frame (MRF) approach. The results show that the flow exits the PS cavity at the near surge condition in the form of three jet-like structures of varying velocity amplitudes. Net entropy generation in the compressor model is used to assess the influence of the ported shroud design on the compressor losses, and the results indicate a small Inlet-PS mixing region is the primary source of entropy generation in the near surge conditions. The analysis also explores the trends of entropy generation at the design and the near surge condition across the different speed lines. The results show that the primary source of entropy generation is the impeller region for the design condition and the inlet-PS cavity region for the near surge condition.

A New Loss and Deviation Model for Axial Compressor Inlet Guide Vanes

2013 ◽  
Author(s):  
Milan Banjac ◽  
Milan V. Petrovic ◽  
Alexander Wiedermann
Keyword(s):  
Guide Vane ◽  
Thickness Distribution ◽  
Axial Compressor ◽  
Algebraic Model ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Viscous Effects ◽  
Through Flow ◽  
Trailing Vortices ◽  
Compressor Inlet

This paper describes a new universal algebraic model for the estimation of flow deflection and losses in axial compressor inlet guide vane devices. The model deals with nominal flow and far-off-design operating conditions in connection with large stagger angle adjustments. The first part of the model considers deflection and losses in 2D cascades, taking into account the main cascade geometry parameters and operating conditions, such as Mach number and stagger adjustment. The second part of the model deals with additional deviation and losses due to secondary flow caused by the endwall viscous effects and by the trailing vortices. The model is developed for NACA65 airfoils, NACA63-A4K6 airfoils and airfoils having an NACA65 thickness distribution on a circular-arc camber line. It is suitable for application in 1D or 2D through-flow calculations for design and analysis cases. The development of the method is based on systematic CFD flow calculations for various cascade geometries and operating parameters. The comparison of correlation results with experimental data for several test cases shows good agreement.

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.

scholarly journals Heat Transfer Analysis for Viscous Fluid Flow with the Newtonian Heating and Effect of Magnetic Force in a Rotating Regime

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Rashid Ayub ◽  
Shahzad Ahmad ◽  
Muhammad Imran Asjad ◽  
Mushtaq Ahmad
Keyword(s):  
Viscous Fluid ◽  
Fluid Motion ◽  
Velocity Fields ◽  
Heat Transfer Analysis ◽  
Convection Flow ◽  
Newtonian Heating ◽  
Flow Parameters ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Temperature And Velocity Fields

In this article, an unsteady free convection flow of MHD viscous fluid over a vertical rotating plate with Newtonian heating and heat generation is analyzed. The dimensionless governing equations for temperature and velocity fields are solved using the Laplace transform technique. Analytical solutions are obtained for the temperature and components of velocity fields. The obtained solutions satisfy the initial and boundary conditions. Some physical aspects of flow parameters on the fluid motion are presented graphically.

Full-Scale Demonstration of Surface-Stabilized Fuel Injectors for Sub-Three ppm NOx Emissions

2004 ◽  
Author(s):  
Steven J. Greenberg ◽  
Neil K. McDougald ◽  
Leonel O. Arellano
Keyword(s):  
Pressure Ratio ◽  
Full Scale ◽  
Low Flow ◽  
Stable Operation ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Fuel Injectors ◽  
Air Inlet ◽  
Radial Profiles ◽  
Developed Surface

ALZETA Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOx emission performance. These injectors use a patented technique to form interacting high-flow and low-flow flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. This technology has been given the product name nanoSTAR™. Previous work involved the development of nanoSTAR technology from the proof-of-concept stage to prototype testing. Rig testing of single injectors and of two injectors simulating a sector of an annular combustion liner have been completed for pressure ratios up to 17 and combustion air inlet temperatures up to 700 K (800°F). This paper presents results from the first ever full-scale demonstration of surface-stabilized fuel injectors. An annular combustion liner, fitted with twelve nanoSTAR injectors was successfully tested up to a pressure ratio of 12 and combustion air inlet temperature of 700 K (800°F). NOx emissions were 2 ppm with CO emissions of 3 ppm both corrected to 15% O2. The combustion system exhibited excellent temperature uniformity around the annular combustor outlet with a maximum pattern factor of 0.16 and engine-appropriate radial profiles.

Alleviation of Shock-Wave Effects on a Highly Loaded Axial Compressor Through Novel Blade Shaping

2016 ◽  
Author(s):  
Alistair John ◽  
Shahrokh Shahpar ◽  
Ning Qin
Keyword(s):  
Axial Compressor ◽  
Free Form ◽  
Stable Operation ◽  
The Novel ◽  
Negative Effects ◽  
3D Design ◽  
Free Form Deformation ◽  
Wave Effects ◽  
Simulation Optimisation ◽  
Highly Loaded

This paper describes the use of the Free-Form-Deformation [1] parameterisation method to create a novel blade shape for a highly loaded, transonic axial compressor. The novel geometry makes use of pre-compression (via an S-shaping of the blade around mid-span) to weaken the shock and improve the aerodynamic performance. It has been known for some time that reducing the pre-shock Mach number of transonic compressors (via pre-compression) can improve their efficiency [2]. However, early attempts at this in the 60s [3] showed undesirable results (such as bi-stable operation), leading the design community to shy away from using pre-compression [4]. This issue is re-addressed here. It is shown that using modern simulation, optimisation and a 3D design, large amounts of pre-compression may be employed without the negative effects that plagued early attempts. This paper shows how Free-Form-Deformation offers superior flexibility over traditionally used parameterisation methods. The novel design (produced via an efficient optimisation method) is presented and the resulting flow analysed in detail. The efficiency benefit is over 2%, surpassing other results in the literature for the same geometry. The pre-compression effect of the S-shape is analysed and explained, and the entropy increase across the shock (along the mid-blade line) is shown to be reduced by almost 80%. Adjoint surface sensitivity analysis of the datum and optimised designs is presented, showing that the S-shape is located in the region predicted to be most significant for changes in efficiency. Finally the off-design performance of the blade is analysed across the rotor characteristics at various speeds.

CTV: A New Method for Mapping a Full Scale Prototype of an Axial Compressor

1996 ◽  
Author(s):  
Vasco Mezzedimi ◽  
Pierluigi Nava ◽  
Dave Hamilla
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Theoretical Basis ◽  
Axial Compressor ◽  
Heavy Duty ◽  
Test Vehicle ◽  
Testing Method ◽  
Area Reduction ◽  
Speed Range ◽  
Compressor Inlet

The full mapping of a new gas turbine axial compressor at different speeds, IGV settings and pressure ratios (from choking to surge) has been performed utilizing a complete gas turbine with a suitable set of modifications. The main additions and modifications, necessary to transform the turbine into the Compressor Test Vehicle (CTV), are: - Compressor inlet throttling valve addition - Compressor discharge bleed valve addition - Turbine 1st stage nozzle area reduction - Starting engine change (increase in output and speed range). This method has been successfully employed on two different single shaft heavy-duty gas turbines (with a power rating of 11MW and 170 MW respectively). The paper describes the theoretical basis of this testing method and a specific application with the above mentioned 170 MW machine.

Numerical Investigation on the Effect of Bleed Port With Self-Recirculating Casing Treatment on the Stability of a 1.5-Stage Transonic Compressor

2019 ◽  
Author(s):  
Yiming Zhong ◽  
WuLi Chu ◽  
HaoGuang Zhang
Keyword(s):  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Stability Margin ◽  
Axial Position ◽  
Stable Operation ◽  
Stall Margin ◽  
Casing Treatment ◽  
Transonic Compressor ◽  
Compressor Efficiency

Abstract Compared to the traditional casing treatment, the self-recirculating casing treatment (SCT) can improve or not decrease the compressor efficiency while achieving the stall margin improvement. For the bleed port, the main design indicator is to reduce the flow loss caused by suction, while providing sufficient jet flow and jet pressure to the injector. In order to gain a better study of the bleed port stabilization mechanisms, the bleed configuration was parameterized with the bleed port inlet width and the bleed port axial position. Five kinds of recirculating casing treatments were applied to a 1.5-stage transonic axial compressor with the method of three-dimensional unsteady numerical simulation. Fifteen identical self-recirculating devices are uniformly mounted around the annulus. The numerical results show that the SCT can improve compressor total pressure ratio and stability, shift the stall margin towards lower mass flows. Furthermore, it has no impact on compressor efficiency. The optimal case presents that stability margin is improved by 6.7% employing 3.1% of the annulus mass flow. Expanding bleed port inlet width to an intermediate level can further enhance compressor stability, but excessive bleed port inlet width will reduce the stabilization effect. The optimal bleed port position is located in the blocked area of the low energy group at the top of the rotor. In the case of solid casing, stall inception was the tip blockage, which was mainly triggered by the interaction of the tip leakage vortex and passage shock. From radial distribution, the casing treatment predominantly affects the above 70% span. The reduction of tip reflux region by suction effect is the main reason for the extension of stable operation range. The SCT also has an obvious stability improvement in tip blockage stall, while delaying the occurrence of compressor stall.

Gas Turbine Compressor Interstage Cooling Using Methanol

1983 ◽  
Vol 105 (4) ◽  
pp. 859-864 ◽  
Author(s):  
J. A. C. Fortin ◽  
M. F. Bardon
Keyword(s):  
Gas Turbine ◽  
Computer Analysis ◽  
Thermal Efficiency ◽  
Full Potential ◽  
Liquid Equilibrium ◽  
Air Temperatures ◽  
Compressor Inlet ◽  
Gas Turbine Compressor

An earlier study demonstrated the theoretical potential of the concept of injecting methanol into a gas turbine compressor inlet as a means of increasing cycle thermal efficiency. To attain the full potential of such a system, continuous shifting vapour/liquid equilibrium is required which would pose formidable difficulties in practice due to the presence of liquid in the compressor blading. This study evaluates a more practicable configuration in which the alcohol is injected between stages of a multistage machine so that, due to the higher air temperatures, evaporation is complete before the mixture enters subsequent stages. Through a computer analysis, it is shown that this arrangement would retain most of the potential of the concept while greatly reducing the design and operating problems.

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