Effect of Interstage Injection on Compressor Flow Characteristic

2019 ◽  
Author(s):  
Inez Von Deschwanden ◽  
Stefan Braun ◽  
Dieter Brillert
Keyword(s):  
Gas Flow ◽  
Fluid Dynamic ◽  
Water Injection ◽  
Operating Conditions ◽  
Wake Flow ◽  
Water Evaporation ◽  
Water Spray ◽  
Trailing Edge ◽  
Wet Compression ◽  
The Impact

Abstract Wet compression is a widely used approach to enhance the compressor performance of gas turbine units. For wet compression, a water-spray consisting of tiny droplets is injected into the air inlet duct of the compressor. A multi-phase flow of humid air and water droplets enters the compressor. The continued water evaporation inside the compressor stages causes further cooling during the compression process. Water injection between the compressor stages is called interstage injection. An advantage of interstage injection compared to wet compression is the optimized injection of water at specific positions inside the compressor. The amount of injected water can be adopted to the specific operating conditions of the different injection positions with the ideal of isothermal compression. Interstage injection can be realized by several techniques. This paper focuses on interstage injection of water from the trailing edge of stator blades. The water spray is generated in the complex wake flow of the airfoil. This leads to strong interaction between the water spray and the carrier gas flow. In this paper, especially the impact of water injection on the air flow and the spread of the spray is investigated. Phase Doppler Anemometry (PDA) measurements enable two dimensional velocity measurements linked with the droplet size. The comparison of PDA measurements and Computational Fluid Dynamic (CFD) calculations of the dry gas flow allows for the identification of flow instabilities due to interstage injection. Within this publication, a significant influence of the water injection from the trailing edge on the carrier flow is identified. Furthermore, the ability of the spray to spread widely into the flow demonstrates that water injection from the trailing edge is a promising technique for interstage injection.

Experimental Investigation of the Aerodynamic Performance of a Linear Axial Compressor Cascade With Water Droplet Loading

2010 ◽  
Author(s):  
Tjark Eisfeld ◽  
Franz Joos
Keyword(s):  
Water Injection ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Two Dimensional ◽  
Compressor Cascade ◽  
Compressor Rotor ◽  
Two Dimensional Flow ◽  
Wet Compression ◽  
The Impact

Wet compression operation is a commercially attractive way to increase power output and efficiency of a gas turbine cycle. In recent literature the impact of water loading on the aerodynamic performance of the blading has not been entirely clarified yet. The most significant issues of aerodynamics in wet compression are stage rematching and stability. Therefore, these subjects are investigated in a linear compressor rotor cascade. This setup allows an estimation of the aerodynamic performance of the blading from two-dimensional test data at various operating conditions. Moreover, the impact of droplet flow on the two-dimensional flow field of the blade passage is measured in detail in order to understand the deviation of performance parameters. The results indicate that the effect of water injection on compressor aerodynamics is strongly related to the operating condition. It appears that droplet loading has a beneficial effect on the flow at high blade loading.

Flow Assessment on the Effects of Water Droplets on Rotor Region of Wet Compression

2017 ◽  
Vol 374 ◽  
pp. 131-147
Author(s):  
Gambo Kofar Bai Dayyabu ◽  
Hai Zhang ◽  
Qun Zheng ◽  
Salman Abdu
Keyword(s):  
Gas Turbine ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Water Droplets ◽  
Compression Process ◽  
Transonic Compressor ◽  
Depth Analysis ◽  
Wet Compression

Wet compression process has been widely accepted as a measure of increasing the performance of industrial gas turbine, in the present work, in-depth analysis on the principle aspects of wet compression, more specifically, the influence of injected water droplets diameter, surface temperature, and their effects on the behavior of axial flow transonic compressor and gas turbine performance were analyzed using computational fluid dynamic. Injected water droplets and gas flow phase change was most intense in the area adjacent to shockwaves and were the slip velocity of the droplet is highest. Water injection in to the compressor rotor is a little perturbation to the flow field due to the formation of flow separation, evaporation rate, increasing weber number, reduction in the inlet temperature, and velocity vortex pattern relatively different from that of the dry case. The effects of water droplets on the rotor region at injection rate of 1%, shows decrease in the inlet temperature of 11%, outlet temperature 5% and uplift the efficiency to 1.5%.

scholarly journals CO₂ STRIPPING FROM DIETHANOLAMINE USING MEMBRANE CONTACTORS: MODEL VALIDATION AND MEMBRANE WETTABILITY

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
H. N. Mohammed ◽  
Omar S. Lateef ◽  
Ghassan H. Abdullah ◽  
A. L. Ahmad
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
Polyvinylidene Fluoride ◽  
Gas Flow ◽  
Hollow Fiber Membrane ◽  
Operating Conditions ◽  
Co Stripping ◽  
Sweeping Gas ◽  
Membrane Contactors ◽  
The Impact

In the present work, CO2 desorption (stripping) from diethanolamine (DEA) solution using polyvinylidene fluoride hollow fiber membrane contactor is theoretically investigated. A comprehensive two dimensional mathematical model is developed to evaluate the membrane wettability when DEA solution is used at different operating conditions such as sweeping gas flow rate, initial CO2 loading and liquid phase temperature. In addition, the impact of flow rate of liquid phase on the CO2 stripping performance was theoretically investigated. The simulated results were compared with the experimental data obtained from literature. The results revealed that the PVDF membrane was suffered from wetting at studied operating conditions.

Wet Compression Effects on Axial Compressor Performance Using Pitch-Line Models

2010 ◽  
Author(s):  
Arathi K. Gopinath ◽  
Giridhar Jothiprasad ◽  
Trevor Wood ◽  
Le Tran
Keyword(s):  
Axial Compressor ◽  
Water Evaporation ◽  
Performance Predictions ◽  
Blade Row ◽  
Compressor Inlet ◽  
Droplet Sizes ◽  
Compressor Performance ◽  
Wet Compression ◽  
Compression Effects ◽  
The Impact

The impact of wet compression technology on compressor performance is studied using a coupled water-evaporation-pitch-line numerical model. The model uses an iterative approach to compute the modified flow conditions at blade-row stations due to inter-stage evaporation of water droplets introduced at the compressor inlet. The evaporation rate predicted by the model is compared with experimental data for stationary droplets in a duct. Performance predictions are compared with data for a GE-proprietary compressor. Study of various water droplet sizes and various water-to-air mass ratios is discussed.

Experimental Determination of a Four Stage Axial Compressor Map Operating in Wet Compression

2014 ◽  
Author(s):  
J. P. Schnitzler ◽  
I. von Deschwanden ◽  
S. Clauss ◽  
F. K. Benra ◽  
H. J. Dohmen ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Flow Behavior ◽  
Water Injection ◽  
Axial Compressor ◽  
Evaporation Process ◽  
Water Droplets ◽  
Test Rig ◽  
Measurement Results ◽  
Wet Compression ◽  
The Impact

Injecting water in the air upstream of an axial compressor intake is an effective method to increase the efficiency and the power output of a gas turbine application especially at hot days. Reasoned by their complex two phase flow axial compressors which operate in wet compression mode are in the focus of present thermodynamic analysis, numerical investigations and experimental research. Recently the evaporation process of water droplets, especially at high temperature and pressure levels has been investigated with the laser based measurement technique Phase Doppler Particle Analyzer (PDPA) in detail in a stationary test rig at the University of Duisburg-Essen. The focus of these investigations has been laid on the analysis of the evaporation process in a free stream or cross flow behavior without droplet wall interaction. In this paper the first results of the novel four stage axial compressor test rig are published. This test rig is arranged for high amount of water injection with special optical access for laser based measurements. The first part of the paper outlines the general design, geometric facts and aerodynamic reference parameters of the test rig and gives an introduction to the installed conventional measurement technique. Discrete measurement results from dry runs are compared with CFD results to validate the gathered experimental data. In the second part of the paper the previously discussed dry runs are compared with measurement results of runs with water injection. The amount of water to air ratio is varied and the effects on the operating behavior of the four stage axial compressor are pointed out in detail. Furthermore results from the laser based PDPA measurements at the inlet and at the outlet of the compressor outline the impact on the water droplets moving through the compressor in wet compression mode.

Multiphase CFD Model Development for a Rotating Centrifugal Separator

2012 ◽  
Author(s):  
Daniel DeMore ◽  
William Maier
Keyword(s):  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Model Development ◽  
Modeling Method ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Separation Performance ◽  
Centrifugal Separator ◽  
Wide Range ◽  
The Impact

The present paper describes the development of a Computational Fluid Dynamic (CFD) modeling approach suitable for the analysis, design, and optimization of rotating centrifugal separator stage geometries. The Homogeneous Multiple Size Group (MUSIG) model implemented in the commercial code CFX V13.0 was utilized as a basis for the CFD modeling method. The model was developed through a series of studies to understand the impact of droplet size distribution, particle coalescence, rotor/stator interface treatment, and mesh resolution on the prediction of separation efficiency for a given rotating separator geometry. This model was then validated against the OEM’s extensive in-house experimental separation testing database. The resulting CFD modeling method is shown to adequately reproduce observed trends in separation performance over a wide range of operating conditions.

scholarly journals Effect of the Extended Rigid Flapping Trailing Edge Fringe on an S833 Airfoil

2022 ◽  
Vol 12 (1) ◽  
pp. 444
Author(s):  
Hongtao Yu ◽  
Zifeng Yang
Keyword(s):  
Flow Field ◽  
Flow Characteristics ◽  
Aerodynamic Performance ◽  
Substantial Effect ◽  
Wake Flow ◽  
Trailing Edge ◽  
Large Vortex ◽  
2D Numerical Simulation ◽  
Angular Amplitude ◽  
The Impact

A 2D numerical simulation was conducted to investigate the effect of an extended rigid trailing edge fringe with a flapping motion on the S833 airfoil and its wake flow field, as an analogy of an owl’s wing. This study aims to characterize the influence of the extended flapping fringe on the aerodynamic performance and the wake flow characteristics downstream of the airfoil. The length (Le) and flapping frequencies (fe) of the fringe are the key parameters that dominate the impact on the airfoil and the flow field, given that the oscillation angular amplitude is fixed at 5°. The simulation results demonstrated that the airfoil with an extended fringe of 10% of the chord at a flapping frequency of fe = 110 Hz showed a substantial effect on the pressure distribution on the airfoil and the flow characteristics downstream of the airfoil. An irregular vortex street was predicted downstream, thus causing attenuations of the vorticities, and shorter streamwise gaps between each pair of vortices. The extended flapping fringe at a lower frequency than the natural shedding vortex frequency can effectively break the large vortex structure up into smaller scales, thus leading to an accelerated attenuation of vorticities in the wake.

Unsteady Computational Fluid Dynamic Analysis of the Behavior of Guide Vane Trailing‐Edge Injection and Its Effects on Downstream Rotor Performance in a Francis Hydroturbine

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Bryan J. Lewis ◽  
John M. Cimbala
Keyword(s):  
Guide Vane ◽  
Flow Direction ◽  
Fluid Dynamic ◽  
Water Injection ◽  
Cfd Simulations ◽  
Trailing Edge ◽  
Computational Fluid Dynamic Analysis ◽  
Flow Angle ◽  
Turbine Efficiency ◽  
Francis Hydroturbine

A unique guide vane design, which includes trailing-edge jets, is presented for a mixed-flow Francis hydroturbine. The water injection causes a change in bulk flow direction at the inlet of the rotor. When properly tuned, altering the flow angle results in a significant improvement in turbine efficiency during off-design operation. Unsteady CFD simulations show nearly 1% improvement in overall turbine efficiency with the use of injection. This revolutionary concept also has the ability to reduce the intensity of the rotor–stator interactions (RSI) by compensating for the momentum deficit of the wicket gate wakes. This technology may be equally applied to other turbomachinery devices with problematic rotor–stator flow misalignments.

Experimental and Numerical Investigation of the Unsteady Flow Field in a Vaned Diffuser of a High-Speed Centrifugal Compressor

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Klemens Vogel ◽  
Reza S. Abhari ◽  
Armin Zemp
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Fluctuations ◽  
Leading Edge ◽  
Fast Response ◽  
Operating Conditions ◽  
Wake Flow ◽  
Vaned Diffuser ◽  
Wide Range ◽  
The Impact

Vaned diffusers in centrifugal compressor stages are used to achieve higher stage pressure ratios, higher stage efficiencies, and more compact designs. The interaction of the stationary diffuser with the impeller can lead to resonant vibration with potentially devastating effects. This paper presents unsteady diffuser vane surface pressure measurements using in-house developed, flush mounted, fast response piezoresistive pressure transducers. The unsteady pressures were recorded for nine operating conditions, covering a wide range of the compressor map. Experimental work was complemented by 3D unsteady computational fluid dynamics (CFD) simulations using ansys cfx V12.1 to detail the unsteady diffuser aerodynamics. Pressure fluctuations of up to 34.4% of the inlet pressure were found. High pressure variations are present all along the vane and are not restricted to the leading edge region. Frequency analysis of the measured vane surface pressures show that reduced impeller loading, and the corresponding reduction of tip leakage fluid changes the characteristics of the fluctuations from a main blade count to a total blade count. The unsteady pressure fluctuations in the diffuser originate from three distinct locations. The impact of the jet-wake flow leaving the impeller results in high variation close to the leading edge. It was observed that CFD results overpredicted the amplitude of the pressure fluctuation on average by 62%.

scholarly journals Methodological Approach for 1D Simulation of Port Water Injection for Knock Mitigation in a Turbocharged DISI Engine

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4297
Author(s):  
Federico Millo ◽  
Fabrizio Gullino ◽  
Luciano Rolando
Keyword(s):  
Film Formation ◽  
Methodological Approach ◽  
Direct Injection ◽  
Water Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Transient Phenomena ◽  
Wall Film ◽  
The Impact

In the upcoming years, more challenging CO2 emission targets along with the introduction of more severe Real Driving Emissions limits are expected to foster the development and the exploitation of innovative technologies to further improve the efficiency of automotive Spark Ignition (SI) engines. Among these technologies, Water Injection (WI), thanks to its knock mitigation capabilities, can represent a valuable solution, although it may significantly increase the complexity of engine design and calibration. Since, to tackle such a complexity, reliable virtual development tools seem to be mandatory, this paper aims to describe a quasi-dimensional approach to model a Port Water Injection (PWI) system integrated in a Turbocharged Direct Injection Spark Ignition (T-DISI) engine. Through a port-puddling model calibrated with 3D-CFD data, the proposed methodology was proven to be able to properly replicate transient phenomena of water wall film formation, catching cycle by cycle the amount of water that enters into the cylinder and is therefore available for knock mitigation. Moreover, when compared with experimental measurements under steady state operating conditions, this method showed good capabilities to predict the impact of the water content on the combustion process and on the knock occurrence likelihood.

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