Internal Flow Analysis in a Two-Channel Pump Used for Salt Transportation

2018 ◽  
Author(s):  
Jiaqi Wang ◽  
Xianwu Luo ◽  
Wanming Li ◽  
Bin Ji
Keyword(s):  
Particle Concentration ◽  
Flow Analysis ◽  
Internal Flow ◽  
Leading Edge ◽  
Pressure Side ◽  
Operation Condition ◽  
Static State ◽  
Erosion Risk ◽  
Salt Particle ◽  
Blade Leading Edge

Two-channel pumps usually have very complicated flow field due to the special impeller geometry. The present paper treats the internal flow analysis based on numerical simulation so as to investigate the pumping performance and passage erosion for a two-channel centrifugal pump used for transporting salt particles. The static state flows are calculated by applying RANS method and k-omega SST turbulence model. The numerical results indicate that there are strong circulation flows near the impeller inlet and blade pressure side, and zones with high turbulent kinetic energy near impeller exit when the pump is operated under the designed flow rate i.e. Qd. Pressure decay is also found at the rear part of blade pressure side. At the operation condition of 1.3Qd, the internal flow becomes better. Further, the numerical analysis based on Eulerian-Lagrangian method shows the trajectory of salt particle, salt particle concentration and erosion rate in the pump. It is noted that the salt particles go smoothly in the flow passage due to the large section size of the pump, and there is severe erosion at the blade leading edge and the wall of volute casing due to strong impingement and high particle concentration. Thus, these areas such as blade leading edge and the wall of volute casing are the zones with high erosion risk in the two-channel pump.

Flow Field Analysis and Nearfield Acoustic Signature Reduction of a Stationary Fan Blade Array

2020 ◽  
Author(s):  
Syed Qasim Zaheer ◽  
Peter Disimile
Keyword(s):  
Flow Field ◽  
Vortex Shedding ◽  
Leading Edge ◽  
Pressure Side ◽  
Validation Data ◽  
Array Configuration ◽  
Blade Cascade ◽  
Fan Blade ◽  
The Impact ◽  
Blade Leading Edge

Abstract A highly cambered and loaded stationary fan blade cascade of an in-service centrifugal fan is analyzed in this research work at flow conditions corresponding to design point operation of subject fan. The configuration of enclosed blade cascade includes upstream and downstream ducts. A preliminary analysis of flow variables and nearfield acoustic spectra is carried out experimentally which then provided boundary conditions and validation data for an extensive numerical analysis using Embedded Large Eddy Simulation turbulence model in ANSYS Fluent 19.0 ® environment. The comprehensive analysis of flow field and nearfield aeroacoustics of blade array configuration reveals vortex shedding from blade leading edge and its interaction with pressure side surface of adjacent blade becomes one of major source in the aeroacoustics signature of blade array. The vortex shedding frequency and the frequency of upstream turbulence interaction with blade leading edge are identified. A novel method of placing rectangular cavity on pressure side of blade array to suppress the impact of impingement of leading-edge vortex via cavity acoustic wave is explored. The numerical results reveal a reduction in noise by 6dB encouraging the efficacy of this method as a passive technique to reduce aeroacoustics signature of researched blade array configuration.

On Line Compressor Washing on Large Frame 9-FA Gas Turbines: Erosion on R0 Compressor Blade Leading Edge — Field Performance With a Novel On Line Wash System

2007 ◽  
Author(s):  
Jos Oosting ◽  
Klaas Boonstra ◽  
Annemarie de Haan ◽  
Dick van der Vecht ◽  
Jean-Pierre Stalder ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Leading Edge ◽  
Compressor Blade ◽  
Cleaning Efficiency ◽  
Compressor Blades ◽  
Erosion Risk ◽  
Plant Operator ◽  
On Line ◽  
Blade Leading Edge

On line compressor washing is an established practice amid gas turbine operators. Among these operators is the Netherlands Division of Electrabel who is operating at Eemshaven 5 x GE Frame 9-FA units since 1995. The plant operator used to perform routinely a daily on line wash and a single off line wash every year at shut down of the units for the annual inspection or maintenance outage. The on line water wash (OLWW) systems installed on these 5 engines are of the Turbotect Mk1 nozzle design and were originally procured and supplied by the OEM. To our knowledge, all other manufactured gas turbines in the 7/9-FA fleet are equipped with the OEMs’ own engineered OLWW nozzle systems. The OLWW regime of washing was reduced in June 2001 upon receipt of a recommendation by the OEM to inspect the first stages of the compressor for erosion marks. This recommendation was issued because some events have lead to investigation on erosion issues which materialized in the R0 (first stage rotor) compressor blades in some engines of the 7/9-FA fleet operating with the OEM OLWW system and resulting from frequent compressor wash routine, and/or from water ingestion used in power augmentation. Likewise, during the same time, some gas turbines at Eemscentrale had undergone their first major overhaul which allowed the compressor first row blading to be examined for signs of erosion. It was found that only minor erosion at the R0 blade leading edge had occurred over more than seven years of operation, during which period a daily on line wash had been performed. However, because of the erosion concerns among the 7/9-FA fleet and the OEM-recommended frequent inspections and measures to mitigate the rate of erosion due to droplet impingement, Electrabel investigated independently for a way of further reducing the erosion rate while maintaining on line washing over the lifetime of the gas turbine and improving the cleaning efficiency. To this effect, the OLWW system on unit EC-6 was upgraded in June 2004 with a new on line nozzle system specifically developed for use in large gas turbines. This paper presents the investigation results after some 24 months of operation and routine on line compressor washing. The Turbotect Mk3 OLWW nozzle system demonstrated and confirmed that it is contributing to mitigate the erosion risk on the R0 compressor blade leading edge, and in turn to decrease the number of blending operations over the life time of the R0 compressor blades. This nozzle designed for on line compressor cleaning of large gas turbines achieved a substantially improved cleaning effectiveness, respectively a lower rate in power degradation, by approx. 30 to 40% as compared to the current in use Mk1 OLWW nozzle system.

Computation and Experimental Results of Wear in a Slurry Pump Impeller

1986 ◽  
Vol 200 (6) ◽  
pp. 439-445 ◽  
Author(s):  
K Ahmad ◽  
R C Baker ◽  
A Goulas
Keyword(s):  
Computer Program ◽  
Calculation Method ◽  
Prediction Method ◽  
Internal Flow ◽  
Leading Edge ◽  
Solid Particles ◽  
Experimental Results ◽  
Pressure Side ◽  
Pump Impeller ◽  
Good Agreement

Using a computer program to obtain the internal flow in a pump impeller, the trajectories of solid particles were found and used to predict the regions of wear within the pump. In order to assess the validity of this prediction method tests were undertaken to obtain the erosion-prone areas of the pump by observing the erosion of layers of paint on the pump impeller. There was good agreement but the level of erosion was underestimated by the predictions. The calculation method and the use of paint to obtain wear patterns were both promising methods. Maximum wear in this case was near the leading edge on the pressure side and on the back shroud in the eye of the impeller.

Internal Flow Analysis on Sweeping Jet Actuator

2019 ◽  
Author(s):  
Sushanth Gowda B C ◽  
Vinuth N ◽  
Poornananda T ◽  
Dhanush G J, ◽  
T Paramesh
Keyword(s):  
Flow Analysis ◽  
Internal Flow

Overall Effectiveness for a Film Cooled Turbine Blade Leading Edge With Varying Hole Pitch

2010 ◽  
Author(s):  
Thomas E. Dyson ◽  
Dave G. Bogard ◽  
Justin D. Piggush ◽  
Atul Kohli
Keyword(s):  
Turbine Blade ◽  
Hot Spots ◽  
Leading Edge ◽  
Stagnation Line ◽  
Convective Cooling ◽  
Impingement Cooling ◽  
Blowing Ratio ◽  
Cylindrical Holes ◽  
Overall Effectiveness ◽  
Blade Leading Edge

Overall effectiveness, φ, for a simulated turbine blade leading edge was experimentally measured using a model constructed with a relatively high conductivity material selected so that the Biot number of the model matched engine conditions. The model incorporated three rows of cylindrical holes with the center row positioned on the stagnation line. Internally the model used an impingement cooling configuration. Overall effectiveness was measured for pitch variation from 7.6d to 9.6d for blowing ratios ranging from 0.5 to 3.0, and angle of attack from −7.7° to +7.7°. Performance was evaluated for operation with a constant overall mass flow rate of coolant. Consequently when increasing the pitch, the blowing ratio was increased proportionally. The increased blowing ratio resulted in increased impingement cooling internally and increased convective cooling through the holes. The increased internal and convective cooling compensated, to a degree, for the decreased coolant coverage with increased pitch. Performance was evaluated in terms of laterally averaged φ, but also in terms of the minimum φ. The minimum φ evaluation revealed localized hot spots which are arguably more critical to turbine blade durability than the laterally averaged results. For small increases in pitch there was negligible decrease in performance.

scholarly journals Aerothermal Investigations of Mixing Flow Phenomena in Case of Radially Inclined Ejection Holes at the Leading Edge

1999 ◽  
Author(s):  
Dieter E. Bohn ◽  
Karsten A. Kusterer
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Gas Turbines ◽  
Leading Edge ◽  
Suction Side ◽  
Pressure Side ◽  
Blade Surface ◽  
Cooling Fluid ◽  
Flow Phenomena ◽  
Vortex Systems

A leading edge cooling configuration is investigated numerically by application of a 3-D conjugate fluid flow and heat transfer solver, CHT-Flow. The code has been developed at the Institute of Steam and Gas Turbines, Aachen University of Technology. It works on the basis of an implicit finite volume method combined with a multi-block technique. The cooling configuration is an axial turbine blade cascade with leading edge ejection through two rows of cooling holes. The rows are located in the vicinity of the stagnation line, one row is on the suction side, the other row is on the pressure side. The cooling holes have a radial ejection angle of 45°. This configuration has been investigated experimentally by other authors and the results have been documented as a test case for numerical calculations of ejection flow phenomena. The numerical domain includes the internal cooling fluid supply, the radially inclined holes and the complete external flow field of the turbine vane in a high resolution grid. Periodic boundary conditions have been used in the radial direction. Thus, end wall effects have been excluded. The numerical investigations focus on the aerothermal mixing process in the cooling jets and the impact on the temperature distribution on the blade surface. The radial ejection angles lead to a fully three dimensional and asymmetric jet flow field. Within a secondary flow analysis it can be shown that complex vortex systems are formed in the ejection holes and in the cooling fluid jets. The secondary flow fields include asymmetric kidney vortex systems with one dominating vortex on the back side of the jets. The numerical and experimental data show a good agreement concerning the vortex development. The phenomena on the suction side and the pressure side are principally the same. It can be found that the jets are barely touching the blade surface as the dominating vortex transports hot gas under the jets. Thus, the cooling efficiency is reduced.

EFFECT OF AXIAL CASING GROOVE GEOMETRY ON ROTOR-GROOVE INTERACTIONS IN THE TIP REGION OF A COMPRESSOR

2021 ◽  
pp. 1-54
Author(s):  
Subhra Shankha Koley ◽  
Huang Chen ◽  
Ayush Saraswat ◽  
Joseph Katz
Keyword(s):  
Rotor Blade ◽  
Leading Edge ◽  
Secondary Flows ◽  
Low Flow ◽  
Flow Angle ◽  
Flow Rates ◽  
Piv Measurements ◽  
Tip Leakage ◽  
Large Vortex ◽  
Blade Leading Edge

Abstract This experimental study characterizes the interactions of axial casing grooves with the flow in the tip region of an axial turbomachine. The tests involve grooves with the same inlet overlapping with the rotor blade leading edge, but with different exit directions located upstream. Among them, U grooves, whose circumferential outflow opposes the blade motion, achieve a 60% reduction in stall flowrate, but degrade the efficiency around the best efficiency point (BEP) by 2%. The S grooves, whose outlets are parallel to the blade rotation, improve the stall flowrate by only 36%, but do not degrade the BEP performance. To elucidate the mechanisms involved, stereo-PIV measurements covering the tip region and interior of grooves are performed in a refractive index matched facility. At low flow rates, the inflow into both grooves, which peaks when they are aligned with the blade pressure side, rolls up into a large vortex that lingers within the groove. By design, the outflow from S grooves is circumferentially positive. For the U grooves, fast circumferentially negative outflow peaks at the base of each groove, causing substantial periodic variations in the flow angle near the blade leading edge. At BEP, interactions with both grooves become milder, and most of the tip leakage vortex remains in the passage. Interactions with the S grooves are limited hence they do not degrade the efficiency. In contrast, the inflow into and outflow from the U grooves reverses direction, causing entrainment of secondary flows, which likely contribute to the reduced BEP efficiency.

Influence of Turbine Blade Leading Edge Profile on Film Cooling With Shaped Holes

2017 ◽  
Author(s):  
Mingjie Zhang ◽  
Nian Wang ◽  
Andrew F. Chen ◽  
Je-Chin Han
Keyword(s):  
Turbine Blade ◽  
Film Cooling ◽  
Density Ratio ◽  
Leading Edge ◽  
Stagnation Line ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Edge Profile ◽  
Elliptical Cylinders ◽  
Blade Leading Edge

This paper presents the turbine blade leading edge model film cooling effectiveness with shaped holes, using the pressure sensitive paint (PSP) mass transfer analogy method. The effects of leading edge profile, coolant to mainstream density ratio and blowing ratio are studied. Computational simulations are performed using the realizable k-ε turbulence model. Effectiveness obtained by CFD simulations are compared with experiments. Three leading edge profiles, including one semi-cylinder and two semi-elliptical cylinders with an after body, are investigated. The ratios of major to minor axis of two semi-elliptical cylinders are 1.5 and 2.0, respectively. The leading edge has three rows of shaped holes. For the semi-cylinder model, shaped holes are located at 0 degrees (stagnation line) and ± 30 degrees. Row spacing between cooling holes and the distance between impingement plate and stagnation line are the same for three leading edge models. The coolant to mainstream density ratio varies from 1.0 to 1.5 and 2.0, and the blowing ratio varies from 0.5 to 1.0 and 1.5. Mainstream Reynolds number is about 100,900 based on the diameter of the leading edge cylinder, and the mainstream turbulence intensity is about 7%. The results provide an understanding of the effects of leading edge profile and on turbine blade leading edge region film cooling with shaped-hole designs.

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