Academic literature on the topic 'Axial flow impeller blades'
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Journal articles on the topic "Axial flow impeller blades"
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Fořt, Ivan, Pavel Seichter, Luboš Pešl, František Rieger, and Tomáš Jirout. "BLENDING CHARACTERISTICS OF HIGH-SPEED ROTARY IMPELLERS." Chemical and Process Engineering 34, no. 4 (December 1, 2013): 427–34. http://dx.doi.org/10.2478/cpe-2013-0035.
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Abstract This paper presents a comparison of the blending efficiency of eight high-speed rotary impellers in a fully baffled cylindrical vessel under the turbulent flow regime of agitated charge. Results of carried out experiments (blending time and impeller power input) confirm that the down pumping axial flow impellers exhibit better blending efficiency than the high-speed rotary impellers with prevailing radial discharge flow. It follows from presented results that, especially for large scale industrial realisations, the axial flow impellers with profiled blades bring maximum energy savings in comparison with the standard impellers with inclined flat blades (pitched blade impellers).
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Mandryka, A., A. P. Majid, Оleksandr Ratushnyi, Oleksandr Kulikov, and D. Sukhostavets. "Ways for Improvement of Reverse Axial Pumps." Journal of Engineering Sciences 9, no. 1 (2022): D14—D19. http://dx.doi.org/10.21272/jes.2022.9(1).d3.
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The article is devoted to a pilot study of the reverse-bladed pump. The characteristics of the reverse bladed pump are the identical parameters on flow, the head, power, energy efficiency on direct and the return operating modes (at rotation of a rotor of the pump both in one and to the opposite side). The model reversible axial pump with two impeller versions was tested on an experimental bench. The impellers were distinguished by the shape of the profile in the blade sections. The model reversible pump was structurally a reversible axial impeller placed in a cylindrical chamber. Studies were carried out at different angles of rotation of the impeller blades. The power characteristics of tested versions of the pump (impeller) at the design and under loading (unstable operation) modes are given. Low efficiency of the tested versions of the reversible pump compared to the conventional axial pumps is noted, primarily due to the strong influence of the secondary gradients of the pressure factor. The second reason is the profile separation of the flow from the blade surface, to which the tested reverse pump screens are predisposed.
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Fořt, Ivan, Miloslav Hošťálek, and Jaroslav Medek. "Liquid circulation in a cylindrical vessel with radial baffles and inclined blade impeller." Collection of Czechoslovak Chemical Communications 54, no. 6 (1989): 1599–611. http://dx.doi.org/10.1135/cccc19891599.
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Liquid circulation was studied in a cylindrical vessel with radial baffles under the turbulent flow regime of liquid agitated gradually with the following types of four inclined blade impellers: impeller with plane blades inclined at the angle of 25°; impeller with asymmetrically profiled blades at the angle of 30°-17°; impeller with strength-profiled blades. By solving the turbulent (vortex) analogy of the Stokes equations for the creeping (non-inertial) laminar flow, the streamline distribution (the Stokes stream function) in the bulk of agitated charge was obtained for each of impellers studied (relative size d/D = 1/3, relative distance from the bottom H2/D = 1/3, relative vessel filling H/D = 1), placed axisymmetrically in the vessel and pumping the liquid towards its flat bottom. The zero values of the Stokes stream function at the bottom, walls, and charge liquid level, and further the radial profiles of axial and radial component of mean velocity in the cross sections under and above the impeller obtained experimentally by the laser-doppler anemometry on the assumption of axial symmetry of the agitated system studied were set as the boundary conditions for the solution of the partial differential equation considered. It follows from the results obtained that the homogenous circulation of agitated charge at the relatively lowest value of the impeller power input is reached when agitating with the asymmetrically profiled blade impeller which therefore can successfully replace the propeller mixer with airfoil profiled blades.
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Chen, Qian, Yang Lihuan, Qi Zhipeng, and Yang Congxin. "Analysis of the axial force distribution characteristics of multistage pumps and its correlation with hydraulic property." Advances in Mechanical Engineering 14, no. 10 (October 2022): 168781322211305. http://dx.doi.org/10.1177/16878132221130565.
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As the centrifugal pump is running, the fluid usually flows into the impeller along pump shaft, and the fluid flows out radially by the force of the impeller. The force is mutual, so the impeller is also subjected to the reaction force of the fluid, but the distribution of this force on the blades is uneven. In addition, the front and rear shrouds of the impeller are asymmetric, which are the main causes of axial force. This paper adopts numerical calculation method studying the mechanism of axial force of impeller at all stages of multistage pump at various working conditions, and exploring the formation mechanism of shroud pressure differential force and blade twisting axial force and its variation laws of similarities and differences, analyzing the steady state and transient characteristics between axial force and hydraulic property of double-casing multistage pump. The results show that the rotational angular velocity of the fluid in the front and rear pump chamber at each stage impeller is distributed along the axial direction in three regions, the regions are pump body boundary layer, core region, and impeller boundary layer. The working surface and back surface of the blade twist have the high and low axial force area, and its distribution is staggered, at the same number of stages, the greater the flow rate, the smaller the blade twisting axial force. The shroud pressure differential force with the increase of impeller stages presents a linear increasing trend, conforms to the principle of linear superposition of cover pressure differential force. The total axial force pulsation of multi-stage pump is related to the number of secondary impeller blades, its primary frequency coincides with the secondary impeller blade frequency, increasing the flow rate can reduce the multi-stage pump axial force pulsation amplitude. The pulsation period of single-stage impeller head and efficiency are related to the number of impeller blades, the smaller the number of impeller stages, the stronger the pressure dynamic, and static interference effect of the impeller inlet and outlet. Rotation of the secondary impeller causes dynamic and static interference, which is the main reason for the pulsation of the axial force coefficient in double-casing multistage pumps, the pulsation intensity is related to the periodic generation and shedding of the blade vortex. The results of the study can be used as a reference for optimizing the axial force of double-casing multistage pumps.
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Foukrach, Mohammed, and Houari Ameur. "Effect of impeller blade curvature on the hydrodynamics and power consumption in a stirred tank." Chemical Industry and Chemical Engineering Quarterly 26, no. 3 (2020): 259–66. http://dx.doi.org/10.2298/ciceq190804003f.
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The performance of curved bladed turbines (CBTs) for the agitation of Newtonian fluids in cylindrical tanks is investigated. The efficiency of CBT is compared with that of the standard Rushton turbine. Also, effects of the blade height of the new designed impeller are highlighted. The computational fluid dynamics (CFD) study is performed to observe the axial, radial and tangential components of velocities, flow patterns and power consumption. The obtained results revealed that the increase of blade curvature reduces the power consumption. Also, a slight decrease of power number is observed in the turbulent flow regime within unbaffled tanks. In a comparison between the cases studied, the best axial circulation of fluid is given by the impeller with flat blades. The increase of the height of curved blades has generated a stronger tangential flow and enhanced the axial movement of fluid particles, but with further penalty in power input.
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Shen, Simin, Bensheng Huang, Si Huang, Shun Xu, and Shufeng Liu. "Research on Cavitation Flow Dynamics and Entropy Generation Analysis in an Axial Flow Pump." Journal of Sensors 2022 (June 22, 2022): 1–18. http://dx.doi.org/10.1155/2022/7087679.
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The entropy generation theory is introduced to investigate the effects of different NPSH and tip clearance size on the cavitation flow dynamics and mechanical energy dissipation intuitively and quantitatively within an axial flow pump through numerical simulations. The results indicate that main mechanical energy dissipation of the pump gathers in part impeller and diffuser, and most are turbulent dissipation. Meanwhile, the impeller is the largest place of mechanical energy dissipation of the pump under cavitation conditions, accounting for more than 50%. NPSH has significant effects on the cavitation pattern, which reflects on the field that the areas of attached sheet cavitation and tip leakage vortex cavitation around blades increase obviously with NPSH reducing under the tip clearance of 0.1% span. With NPSH decreasing, high regions of turbulent dissipation in the impeller mainly expands along blades and move downstream, with span S0.98 near the shroud having larger turbulent dissipation. Besides, high regions of turbulent dissipation are mainly distributed at the rear part of the cavity for every corresponding span of the impeller, which indicates that the turbulent dissipation has a strong relation with the cavitation pattern. In the impeller, the unstable flows cause cavity shedding at the rear of the cavity and wake flows near the blade trail induce higher turbulent kinetic energy, finally resulting in higher turbulent dissipation there. Under the same NPSH, areas of tip leakage vortex cavitation and areas of tip clearance cavitation around the tip both expand with the tip clearance increasing from 0.1% span to 0.8% span. And high areas of turbulent dissipation also are distributed at the rear of the cavity and moving downstream along the blade suction side, especially at span S0.98. Therefore, the tip clearance width mainly affects the cavitation development and turbulent dissipation distribution near the impeller’s shroud under same NPSH.
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Shen, Simin, Zhongdong Qian, and Bin Ji. "Numerical Analysis of Mechanical Energy Dissipation for an Axial-Flow Pump Based on Entropy Generation Theory." Energies 12, no. 21 (October 31, 2019): 4162. http://dx.doi.org/10.3390/en12214162.
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Mechanical energy dissipation is a major problem affecting hydraulic machinery especially under partial-load conditions. Owing to limitations of traditional methods in evaluating mechanical energy dissipation, entropy generation theory is introduced to study mechanical energy dissipation with varying discharge and tip clearance intuitively through numerical simulations in an axial-flow pump. Results show that the impeller and diffuser are the main domains of mechanical energy dissipation, respectively accounting for 35.32%–55.51% and 32.61%–20.42% of mechanical energy dissipation throughout the flow passage. The mechanical energy dissipation of the impeller has a strong relation with the hump characteristic and becomes increasingly important with decreasing discharge. Areas of high turbulent dissipation in the impeller are mainly concentrated near the blades’ suction sides, and these regions, especially areas near the shroud, extend with decreasing discharge. When the pump enters the hump region, the distributions of turbulent dissipation near the shroud become disordered and expand towards the impeller’s inlet side. Unstable flows, like flow separation and vortices, near the blades’ suction sides lead to the high turbulent dissipation in the impeller and hump characteristic. Turbulent dissipation at the tip decreases from the blade leading edge to trailing edge, and regions of high dissipation distribute near the leading edge of the blade tip side. An increase in tip clearance for the same discharge mainly increases areas of high turbulent dissipation near the shroud and at the tip of the impeller, finally reducing pump performance.
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Shi, Xiaobing, Jinling Lu, and Lianming Zhao. "Investigations on the influence of tandem blades on inner flow and performance characteristics of centrifugal pump." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 234, no. 1 (October 23, 2019): 46–55. http://dx.doi.org/10.1177/0954408919883730.
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Although significant advances have been made in tandem-blade technology for axial and centrifugal compressors, little attention has been paid to its application in centrifugal pumps. In this study, we propose a new tandem-blade design method for improving inner flow characteristics and overall performance of a centrifugal pump. With the SST k − ω turbulence model, three-dimensional turbulent flow fields in the centrifugal pump with tandem blades are simulated and analyzed. The effects of tandem blades on the inner flow and performance characteristics of the centrifugal pump are investigated. The predicted velocity and pressure distributions and flow behavior of the tandem-blade impeller are compared with those of a conventional single row blade impeller. It is indicated that the centrifugal tandem-blade impeller exhibits a significant advantage in terms of the uniformity of the impeller discharge flow. The tandem blades improve the jet-wake structure and uniformity of velocity and pressure distributions at the impeller outlet, and thus reduce the pressure fluctuation and hydraulic loss. Moreover, the hump phenomenon is eliminated or alleviated under low flow rate conditions, and the tandem-blade impeller has better hydraulic performance within a wider operating range as well as high reliability. This study provides a basis for the further development of the centrifugal pump with tandem blades.
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Zhang, Hong-li, Fan-yu Kong, Ai-xia Zhu, Fei Zhao, and Zhen-fa Xu. "Effect of Blade Outlet Angle on Radial Force of Marine Magnetic Drive Pump." Shock and Vibration 2020 (September 11, 2020): 1–18. http://dx.doi.org/10.1155/2020/8827333.
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To research the effects of the blade outlet angle on the performance and the radial force of the marine pump, the unsteady numerical simulation of the four different models is carried out. The radial forces on the impeller and the blades are obtained under different flow rate conditions. The time and frequency domain characteristics of radial resultant force on the impeller and the blades are analyzed and those of the impeller torque are researched. The results show that the radial forces of the impeller and the blades increase with the increase of the blade outlet angle at the same flow rate. With the same blade outlet angle, the radial forces decrease with the increase of the flow rate. The roundness of radial force vector diagram becomes more obvious with the decrease of the blade outlet angle. The root mean square (RMS) of radial force on the blades is about 30% of that on the impeller. The main frequency of radial force on the impeller and the blades is the axial passing frequency (APF), and that of impeller torque is the blade passing frequency (BPF), and there are peaks at the blade frequency multiplier. At the same flow rate, the main frequency and maximum fluctuation amplitudes on the impeller and the blades increase with the increase of the blade outlet angle. Meanwhile, the impeller torque increases with the increase of the blade outlet angle. With the same blade outlet angle, the main frequency, maximum fluctuation amplitudes, and the impeller torque decrease with the increase of the flow rate. The amplitude difference decreases with the increase of the flow rate. The blade outlet angle has an obvious greater influence on the radial forces and fluctuation at the small flow rate. The vibration test shows that the vibration intensities of model 25 and model 35 are less than 2.5 mm/s, and the vibration intensity of model 25 is about 0.2 mm/s less than that of model 35.
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Fang, Peng, Jianjun Du, and Shunzhou Yu. "Impeller (straight blade) design variations and their influence on the performance of a centrifugal blood pump." International Journal of Artificial Organs 43, no. 12 (April 20, 2020): 782–95. http://dx.doi.org/10.1177/0391398820913559.
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Introduction: The miniaturization of blood pumps has become a trend due to the advantage of easier transplantation, especially for pediatric patients. In small-scale pumps, it is much easier and more cost-efficient to manufacture the impeller with straight blades compared to spiral-profile blades. Methods: Straight-blade impeller designs with different blade angles, blade numbers, and impeller flow passage positions are evaluated using the computational fluid dynamics method. Blade angles (θ = 0°, 20°, 30°, and 40°), blade numbers ( N = 5, 6, 7, and 8), and three positions of impeller flow passage (referred to as top, middle, and bottom) are selected as the studied parametric values. Results: The numerical results reveal that with increasing blade angle, the pressure head and the hydraulic efficiency increase, and the average scalar shear stress and the normalized index of hemolysis decrease. The minimum radial force and axial thrust are obtained when θ equals 20°. In addition, the minimum average scalar shear stress and normalized index of hemolysis values are obtained when N = 6, and the maximum values are obtained when N = 5. Regarding the impeller flow passage position, the axial thrust and the stagnation area forming in the impeller eye are reduced as the flow passage height declines. Conclusion: The consideration of a blade angle can greatly improve the performance of blood pumps, although the influence of the blade number is not very easily determined. The bottom position of the impeller flow passage is the best design.
Dissertations / Theses on the topic "Axial flow impeller blades"
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Wong, Vui-Hong, and n/a. "Finite Element Analysis and Improvement of Impeller Blade Geometry." Griffith University. School of Engineering, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030825.150853.
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Stratification of water in large reservoirs occurs in summer, or at anytime in hot climates where the water surface is exposed long-term to sunlight and the water surface is heated. Natural mixing will not occur due to the cooler and denser water always staying at the lower levels. Therefore, mechanical circulators are designed to prevent water quality problems related to stratification and depletion of dissolved oxygen. Impellers that produce the flow in mechanical circulators are available in different sizes and these impellers are designed to produce different flow rates. Due to hydraulic loadings, impellers have to be strong and durable. Loadings on impellers depend on their geometries and therefore, a durable impeller is a good combination of the use of correct materials and good geometry. Long and slender impellers are prone to failure when subjected to high hydrodynamic loadings. Nowadays, designers have very limited information on predicting the stresses on impellers and the deflection patterns of impellers because there are no design rules in designing these impeller blades and there is no such thing as "best geometry". A good impeller blade design is by guesswork and experience. In order to design the geometry that suits this application, trial-and-error finite element analyses have been conducted in this project to minimize stress levels on the blades. This research involves the use of finite element analysis (FEA) to predict stress and deflection of impeller blades used on large (5m diameter) ducted axial flow impellers as the first step in the design process. Then, based on the results, improvements have been done to the models until the final design was made. As far as the author has been able to determine, this has not been researched before. Finite Element Analysis has been used on wind turbine blades, rudders and hulls of boats but not on axial flow impeller blades of the type used in this project. For the purpose of this project, commercial finite element computer program packages STRAND6 and STRAND7 were used as the main analysis tools. A static line load increasing linearly with radius along the blade has been used to simulate the assumed hydrodynamic loading, and applied to all FEA blade models. The analysis results proved the stresses on blades are largely dependant on the blade geometry. From the analysis results, the author modified the stacking arrangement of the FEA elements in order to minimize both the tensile stresses and the displacements of the blades at the tip. Parametric studies have been done in order to obtain the best FEA impeller blade model.
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Wong, Vui-Hong. "Finite Element Analysis and Improvement of Impeller Blade Geomtery." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367302.
Full textAbstract:
Stratification of water in large reservoirs occurs in summer, or at anytime in hot climates where the water surface is exposed long-term to sunlight and the water surface is heated. Natural mixing will not occur due to the cooler and denser water always staying at the lower levels. Therefore, mechanical circulators are designed to prevent water quality problems related to stratification and depletion of dissolved oxygen. Impellers that produce the flow in mechanical circulators are available in different sizes and these impellers are designed to produce different flow rates. Due to hydraulic loadings, impellers have to be strong and durable. Loadings on impellers depend on their geometries and therefore, a durable impeller is a good combination of the use of correct materials and good geometry. Long and slender impellers are prone to failure when subjected to high hydrodynamic loadings. Nowadays, designers have very limited information on predicting the stresses on impellers and the deflection patterns of impellers because there are no design rules in designing these impeller blades and there is no such thing as "best geometry". A good impeller blade design is by guesswork and experience. In order to design the geometry that suits this application, trial-and-error finite element analyses have been conducted in this project to minimize stress levels on the blades. This research involves the use of finite element analysis (FEA) to predict stress and deflection of impeller blades used on large (5m diameter) ducted axial flow impellers as the first step in the design process. Then, based on the results, improvements have been done to the models until the final design was made. As far as the author has been able to determine, this has not been researched before. Finite Element Analysis has been used on wind turbine blades, rudders and hulls of boats but not on axial flow impeller blades of the type used in this project. For the purpose of this project, commercial finite element computer program packages STRAND6 and STRAND7 were used as the main analysis tools. A static line load increasing linearly with radius along the blade has been used to simulate the assumed hydrodynamic loading, and applied to all FEA blade models. The analysis results proved the stresses on blades are largely dependant on the blade geometry. From the analysis results, the author modified the stacking arrangement of the FEA elements in order to minimize both the tensile stresses and the displacements of the blades at the tip. Parametric studies have been done in order to obtain the best FEA impeller blade model.Thesis (Masters)
Master of Philosophy (MPhil)
School of Engineering
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Li, Yiguang. "Three-Dimensional Flow and Performance Simulation of Multistage Axial Flow Compressors." Thesis, Cranfield University, 2000. http://dspace.lib.cranfield.ac.uk/handle/1826/4591.
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\Yith the current develop111ent in computer technology and Computational
Fluid D)"n<'tlllics techniques, t.he si11utlation within axial flow compressors becomes
1110re and 1110re pract.ical and beneficial to the compressor designs. Due to the
insufficient capabilit)" of today's COll1put.ers for three-dimensional unsteady flow
1110delling of 111Ult i~Llg(' axial flow compressors, sophisticated models of steady
state flow and perfor111ance 1110delling of the C0111prcssors deserve to be thoroughly
investigated.
In l1utltistage C0111pressor sinlulations with steady state methods, frame of reference
is fixed on blades and the c0111putational domains for rotors and stators
haye relati\"e rotation. One of the difficulties in such simulations is how to pass
information across the interfaces between blade rows without losing continuity.
Two 111ajor stead)" state modelling approaches, a mixing plane approach based
on Denton's circu111ferentially non-uniform mixing plane model and a deterministic
stress approach based on Adamczyk's average passage model, are investigated
and compared with each other through the flow predictions of the third stage of
Cranfield Low Speed Research Compressor at peak efficiency operating condition.
In the deterministic stress approach, overlapped solution domains are introduced
to calculate deterministic stresses in order to "close" the time-averaged
governing equation system and the influence of the downstream blade row of the
blade row under investigation has to be imposed through the simulation of bodyforce
and blade blockage effect of the downstream blade row. An effective method
of simulating bodyforce and blade blockage effect has been developed and proven
to be simple in programming.
ConYentionally, boundary conditions are specified in CFD calculations based
on experimental data or other empirical calculations. By taking advantage of the
special flow features in rear stages of multistage axial flow compressors where each
rear stage behaves like a repeating stage of its neighbouring stages in terms of
flow pattern at the inlet and the exit of these stages, a repeating stage model has
been developed aiming at significantly simplifying the boundary conditions when
simulating rear stages of a multistage axial flow compressor with only mass flow
rate and stage exit average static pressure required as global input.
A computer simulation system 1'/ STurbo3D has been developed to investigate
a11d assess different steady state simulation models within multistage compressor
environment. It has been proven that with the mixing plane model M STurbo3D is
able to predict flows in multistage low speed axial flow compressors with acceptable
accuracy. Application of the repeating stage model to the third stage of LS RC
shows that the prediction with this model has equivalent accuracy to the prediction
with the conventional boundary setting, and proves that the repeating stage
model is an effective alternative to the expensive complete compressor simulation.
The deterministic stress model provides more information of rotor-stator interaction
and slightly better performance prediction than the mixing plane model, but
the benefits of the model is not significant when applied to low speed axial flow
compressors.
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Karikh, A. "Interaction of impeller and guide vane in a series-designed axial-flow pump." Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/34873.
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Axial-flow pumps or propeller pumps allow fluid to enter the impeller axially. The impeller can be driven directly by a sealed motor in the pipe or mounted to the pipe from the outside, or by a right angle drive shaft that pierces the pipe. These pumps discharge fluid nearly axially, pumping the liquid in a direction that is parallel to the pump shaft. Axial-flow pumps are typically used in high-flow rate, low-head applications.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34873
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Champhekar, Omkar G. "Inverse Design of Two-Dimensional Centrifugal Pump Impeller Blades using Inviscid Analysis and OpenFOAM." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342544389.
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Kazi, Sheila K. "Numerical study of simulated low Reynolds number axial turbine blades with flow transition." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490816.
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Two main sources of high losses in small axial turbines are the tip leakage loss and the Reynolds number related loss. The extents of these losses are directly related to blade geometry. Due to limitation in manufacturing capabilities and the prohibitive cost of precision engineering often the manufactured blade is very different from the design or the ideal blade shape and as a result the component efficiency degrades. Reynolds number effect plays a very important role in the low efficiency of small axial turbines. The effect of low Reynolds number is essentially separation of the flow resulting in high losses. Unlike in large turbines, where the Reynolds number is above 10e5, depending on size the Reynolds number over which a small turbine operates can be as low as 10e4. At this range the flow is laminar over a large extent of the blade and is very susceptible to laminar separation resulting in high losses. Since due to the aerodynamics this is inevitable, the only resort for an engineer is to design a blade that will delay separation to a point which will either result in turbulent separation or a transitional-laminar separation resulting in a smaller separation bubble. The design of such blades requires in depth knowledge on the field of flow transitional methods. An existing flow transition model has been implemented with simple modifications for separated flow in an in-house CFD code. Once validated against available experimental data, a parametric study has been conducted, where the effects of Reynolds number, velocity ratio, the turbulence levels and the location of maximum loading has been tested on a simulated turbine flow. Two different velocity distributions were tested. The combined results provided an understanding of the aerodynamic behaviour of small low Reynolds number axial turbine blades and provided a basis of better blade design.
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Cobian, Marcela Ivonne. "Investigation on the flow dynamics of mesoscale inlet guide vanes." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Venter, Sarel Jacobus, and D. G. Kroger. "The effectiveness of axial flow fans in a-frame plenums." Thesis, Stellenbosch : University of Stellenbosch, 1990. http://hdl.handle.net/10019.1/15625.
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Thesis (PhD (Mechanical and Mechatronic Engineering)--University of Stellenbosch, 1990.260 leaves printed single pages, preliminary pages i-xxi and numbered pages Chapter 1/1.1-1.3, Chapter 2/2.1-2.17, Chapter 3/3.1.1-3.10, Chapter 4/4.1-4.18, Chapter 5/5.1-5.3, References pages R.1-R.7, Appendix A pages A.1-A.34, Appendix B pages B.1-B.34, Appendix C pages C.1-C.26, Appendix D pages D.1-D.16, Appendix E pages E.1-E.30, Appendix F pages F.1-F.39. Includes bibliography, list of tables, figures and symbols.
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ENGLISH ABSTRACT: The ultimate goal of this project is to ensure a better understanding of the governing mechanisms present when flow distorting components are installed in close proximity of an axial flow fan. The effect of different parameters on the operation of axial flow fans is investigated. These parameters are divided into flow enhancing and flow reduction effects. The performance of an axial flow fan can be enhanced by changing the tip clearance, by adding a solid disc to the hub of the fan or by varying the number of fan blades. Flow reductions are caused by components such as inlet grids, walkways and their supporting structures, heat exchangers and windwalls. The effects of flow enhancing components are measured and compared to the results of other authors. The sensitivity of these effects to parameters such as the type of fan rotor and the specific system in which the rotor is installed is highlighted. The system effect (the interaction between the fan rotor and flow resistances in close proximity of each other) of individual components, as well as the combination of different components, is predicted both theoretically and experimentally. These predictions are compared to measured data relevant to the components in an installation where the system effects are present. The results are correlated to the kinetic energy flux coefficient of the flow at different locations within the installation. Experimental data obtained from a full scale unit (inlet shroud diameter of 9,216 m) are used to compare to scaled data from the model (inlet shroud diameter of 1,542 m). The hub to tip ratio of the axial flow fans investigated is 0,15. The most important conclusions are that the performance of the type of axial flow fan under investigation can be improved by reducing its tip clearance and by installing a solid disc to the downstream side of the rotor. An increase in the number of blades of the fan leads to only marginal improvements in the fan performance. The overall performance of the system can also be improved by removing some of the flow resisting components, or by changing their relative positions. All these conclusions are based on the assumption that the power input to the fan rotor remains constant.
AFRIKAANSE OPSOMMING: Die uiteindelike doel van hierdie projek is om te verseker dat die beherende meganismes wat teenwoordig is wanneer vloeiversteurende komponente in die nabyheid van 'n aksiaalwaaier geinstalleer word, beter verstaan word. Die effek van verskillende parameters op die werkverrigting van aksiaalwaaiers word ondersoek. Hierdie parameters word verdeel in vloeiverbeterings- en vloeiverminderingseffekte. Die werkverrigting van 'n aksiaalwaaier kan verbeter word deur die lempuntspeling te verstel, deur 'n soliede skyf aan die naaf van die waaierrotor te installeer, of deur die aantal lemme te verander. Die vloeiverminderings word veroorsaak deur inlaatsiwwe, loopvlakke en hul ondersteuningsstrukture, warmteruilers en windwande. Die effekte van vloeiverbeteringskomponente word gemeet en vergelyk met die resultate van ander outeurs. Die sensitiwiteit van hierdie effekte op parameters soos die tipe rotor en die spesifieke stelsel waarin die rotor geinstalleer is, word uitgelig. Die stelseleffek (die interaksie tussen die rotor van die waaier en vloei weerstande wat naby mekaar geinstalleer is) van individuele, sowel as 'n kombinasie van verskillende komponente, word teoreties en eksperimenteel voorspel. Hierdie voorspellings word dan vergelyk met eksperimentele data wat van toepassing is op die komponente in 'n installasie waar stelseleffekte voorkom. Die resultate word gekoppel aan die kinetiese energievloedkoeffisient van die vloei by verskillende posisies binne die installasie. Eksperimentele data, verkry vanaf 'n volskaaleenheid (inlaatmondstukdiameter van 9,216 m), word met die geskaleerde data van die model (inlaatmondstukdiameter van 1,542 m) vcrgelyk. Die naaf- tot hulsverhouding van die aksiaalwaaiers wat ondersoek word is 0,15. Die belangrikste gevolgtrekkings is dat die werkverrigting van die tipe aksiaalwaaier wat ondersoek word verbeter kan word deur die lempuntspeling te verminder en deur 'n soliede skyf te installeer by die stroomaf kant van die rotor. 'n Toename in die aantal lemme van die waaier lei slegs tot marginale verbeterings in die werkverrigting van die waaier. Die totale werkverrigting van die stesel kan ook verbeter word deur sommige vloeiweerstandskomponente te verwyder, of deur hulle relatiewe posisies te verander. Al hierdie gevolgtrekkings is gebasseer op die aanname dat die drywingsinset na die waaierrotor konstant bly.
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Williams, David A. "A 3-d model for the operation of a radiation pyrometer in an axial flow turbine." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/80097.
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An accurate knowledge of turbine blade surface temperature is desired in order to obtain maximum performance from turbine engines. A limited spectrum radiation pyrometer can be used for blade temperature measurement. A model is presented which predicts the output signal from the detector unit of a pyrometer in a turbine engine application.
Six inputs are required for the model. The inputs are the turbine blade geometry, location of the pyrometer with respect to the blades being viewed, focusing parameters of the pyrometer, type of detector, transmission curve of the optical system, and an estimate of the blade surface temperature. The model uses Fortran 77 and IBM CADAM to create a three dimensional representation of the pyrometer path across the blades along with the intercepted target spots. Once the target spot areas are determined, the photocurrent output signal of the detector is predicted as a function of percent blade chord and time. Results are shown for different detectors and temperature distributions. Experimental data is also included, and a comparison is made between the data and the model.
Any of the model input parameters can be varied so that different pyrometer schemes can be evaluated at either the initial design phase or after installation.Master of Science
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Shaik, Muneeb Ur Rahman. "Gas Dispersion Using an Up-Pumping Maxflo W Impeller." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1398961959.
Full textBooks on the topic "Axial flow impeller blades"
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Arts, T. Three dimensional rotational inviscid flow calculation in axial turbine blade rows. Rhode Saint Genese, Belgium: Von Karman Institute, 1985.
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Neuhoff, F. Modifications to the inlet flow field of a transonic compressor rotor. Monterey, Calif: Naval Postgraduate School, 1985.
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Arasu, A. Valan. Turbo machines. New Delhi: Vikas Publishing House, 2008.
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Wasserbauer, Charles A. NASA low-speed axial compressor for fundamental research. Cleveland, Ohio: Lewis Research Center, 1995.
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Escudier, Marcel. Flow through axial-flow-turbomachinery blading. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198719878.003.0014.
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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.
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F, Weaver Harold, Senyitko Richard G, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., eds. NASA low-speed axial compressor for fundamental research. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1995.
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F, Weaver Harold, Senyitko Richard G, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., eds. NASA low-speed axial compressor for fundamental research. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1995.
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F, Weaver Harold, Senyitko Richard G, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., eds. NASA low-speed axial compressor for fundamental research. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1995.
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NASA low-speed axial compressor for fundamental research. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1995.
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NASA low-speed axial compressor for fundamental research. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1995.
Find full textBook chapters on the topic "Axial flow impeller blades"
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Bui, Ngoc Tuyen, and Duc Luong Ngo. "An Experimental Study of 3 Axes CNC Milling for a Blade of the Axial Flow Pump Impeller." In Proceedings of the 2nd Annual International Conference on Material, Machines and Methods for Sustainable Development (MMMS2020), 330–36. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69610-8_46.
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Bui, Ngoc-Tuyen, Duc-Luong Ngo, and Duc-Toan Nguyen. "Optimization of 3 Axes CNC Milling for Machining Freeform Surface of the Axial Flow Pump Impeller Blade." In Lecture Notes in Mechanical Engineering, 69–75. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99666-6_11.
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Yang, Minguan, Xiaolian Wu, and Can Kang. "Numerical Simulation of Air-Water Bubbly Flow in Axial Flow Pump Impeller." In IFIP Advances in Information and Communication Technology, 545–52. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-0209-2_56.
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Forstner, Martin, and Helmut Jaberg. "About the Onset of Partload Instability of Swept and Unswept Axial Pump Blades." In Modelling Fluid Flow, 347–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-08797-8_24.
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Greenblatt, David, Omer Pfeffermann, and David Keisar. "DBD Plasma Actuation on the Blades of Axial-Flow Turbomachinery." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 258–71. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-90727-3_16.
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Van den Braembussche, René A., and János Vad. "Challenges in Optimisation of Axial Flow Turbomachinery Blades for 3D Flow, Including Sweep and Dihedral Effects." In Modelling Fluid Flow, 99–103. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-08797-8_7.
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Park, H. S., and Fu-qing Miao. "Multi-objective Optimization by Using Modified PSO Algorithm for Axial Flow Pump Impeller." In Advances in Intelligent Systems and Computing, 223–37. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-11457-6_16.
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Felsch, K. O., and W. Stütz. "Effect of sickle shaped blades on sound generated by axial flow fans." In Fluid- and Gasdynamics, 189–97. Vienna: Springer Vienna, 1994. http://dx.doi.org/10.1007/978-3-7091-9310-5_22.
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Roy, Apurba Kumar, Supriyo Roy, and Kaushik Kumar. "Strategic Designing and Optimization of Mixed Flow Impeller Blades for Maritime Applications." In Handbook of Research on Military, Aeronautical, and Maritime Logistics and Operations, 470–508. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9779-9.ch025.
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Mixed flow impellers are extensively used in turbomachines either to convert mechanical energy to fluid energy or to convert fluid energy to mechanical energy. According to the geometry of flow passage, turbo machines can be classified as radial, axial and mixed flow. Mixed flow turbomachines are widely used for engineering applications like cooling water duties, water intake impellers for maritime applications, flood water draining, irrigation and other application fields. The design of mixed flow impellers of high specific speed is a direct extension of the well-established methods of the designing of radial flow impellers but the introduction of near diagonal flow layout at a still larger specific speed stimulated the incorporation of axial impeller design techniques in mixed flow impeller technology. Here, an attempt has been made to design a mixed flow turbo machine blade from the basic principle of turbomachinery and fluid mechanics. On the basis of stress analysis, the blade positioning in the meridional annulus was selected and validated using artificial neural network.
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Li, Chen. "Influence of Blade Tip Clearance on Performance of Axial-Flow Waterjet Pump." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220403.
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In this paper, the fine/turbo software of NUMECA was used. Based on the three-dimensional steady Reynolds averaged N-S equations, the S-A turbulence model was used to calculate the relationship between tip clearance and diameter of the impeller, which were δ = 0.1%, 0.3%, 0.5% and 0.7% respectively. The clearance flows of four water jet axial flow pumps with different tip clearances were numerically studied at different flow rates. The results indicate that the size of the clearance affects the cavitation performance of the blades, the efficiency and head of the pump, and has a great impact on the performance of the pump. It provides a useful exploration for the design improvement of axial-flow waterjet pump.
Conference papers on the topic "Axial flow impeller blades"
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Swienty, Andreas, Evgenii Palamarchuk, Raja Abou Ackl, and Paul Uwe Thamsen. "Noise Reduction Measures for an Axial Fan." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69287.
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The aim of this work is to investigate how a reduction of the noise emissions can be achieved by means of an irregular arrangement of the blades of the fan impeller and an additional blade skewing. For this purpose a fan impeller with a defined operating point is designed. Preliminary investigations have shown that a volumetric flow rate of 18 m3/h at a pressure of 200 Pa is required for cooling. Due to structural restrictions, only one axial impeller with a diameter of 68 mm can be used. The rotational speed of the electric motor is 10000 rpm. In a further step, the influences of the blade skewing and irregular arrangement of the blades are examined. These impellers are manufactured in a rapid prototyping process, which is a cost-effective and fast process. Thus, various variants can be examined to find the most suitable impeller. The study of the impellers is divided into two phases. Firstly, the fluid mechanical data of the impeller is measured. For this purpose, a chamber test stand is used to measure the characteristic curves of fan impellers. Thus, on the one hand, it can be examined whether the designed impeller reaches the operating point and, on the other hand, the influence of the noise reduction measures on the characteristic curves can also be evaluated. It is, of course, not desired that the noise reduction measures result in a deterioration of the pressure increase or in the volumetric flow rate. In the second phase, the noise generation of the impeller is measured in an installed state on an acoustic test stand. For this purpose, the impellers are installed in the electric motor and then acoustically examined in enveloping surface method according to DIN 45635. It can be seen that the sound load can be reduced by 5.6 dB by a sufficient design of the impeller compared to a reference impeller. The further measures taken, such as the irregular arrangement of the blades and the blade skewing, have shown a further improvement of 1.6 dB. The influence of the implemented measures on the characteristic curve lies in a small area. It is measured that the pressure increase has fallen due to the irregular arrangement of the blades and the blade skewing by 10 Pa with a constant remaining flow rate.
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Zhu, Honggeng, Rentian Zhang, Bin Xi, and Dapeng Hu. "Internal Flow Mechanism of Axial-Flow Pump With Adjustable Guide Vanes." In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16613.
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Axial-flow pumps are widely used in many fields where low pumping head and large flow rate are required such as irrigation and drainage, flood control, bio-environmental protection and inter-basin water diversion. Conventional axial-flow pump diffuser is designed with post fixed guide vanes to eliminate circulation, diffuse water and decrease flow velocity while converting dynamic energy to pressure energy. Under designed flow rate the inlet setting angle of the fixed guide vanes is designed to be equal to the outlet flow angle of the impeller blades which is regarded to be the best operating condition. Under off-design conditions the outlet flow angle of the impeller blades does not match the inlet setting angle of guide vanes any more. As a result hydraulic losses are increased, flow separation appeared and vortex generated inside the diffuser, the operation conditions of pump is deteriorated, bringing in bad cavitation characteristics, more energy consumption and lower pumping efficiency. The proposal of Axial-flow pumps with adjustable guide vanes are put forward in this paper, in which the inlet setting angle of guide vanes can be adjusted to coordinate with the change of flow rate and impeller blade setting angle and guarantee the outlet flow angle of impeller blades matching the inlet setting angle of guide vanes. The three-dimensional time-averaged N-S equations, closed by the standard κ–ε turbulence model, are adopted to simulate the internal flow fields of axial-flow pumps with fixed and adjustable guide vanes, and their performances are predicted. The internal flow mechanism of an axial-flow pump with adjustable guide vanes is investigated, and computational fluid dynamics is adopted to simulate and analyze the internal flow fields. Computation results indicate that the value of the highest pumping efficiency is slight changed while the vane setting angle is adjusted when the inlet setting angles of blades are fixed and the setting angles of guide vanes are regulated. Under off-design conditions the flow conditions inside the diffuser of axial-flow pump with adjustable guide vanes can be improved, the hydraulic loss reduced and the pumping efficiency can be raised effectively.
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Li, Yaojun, and Fujun Wang. "Computer-Aided Design and Numerical Flow Analysis of Axial-Flow Pump With Inducer." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95369.
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Axial-flow pump equipped with inducer are widely used in marine propulsion systems. The interaction of inducer and impeller has significant effect on the performance of pump. In this study, a special axial-flow pump is designed and analysed by CAD-CFD approaches to study the interaction of inducer and impeller. The pump includes two main elements, an inducer with 3 blades mounted on a conical hub and a 6-blade impeller. The blade angle of impeller is adjustable to generate different relative circumferential angles between the inducer blade trailing edge and the impeller blade leading edge. The 3D pump solid model is generated by taking the data file as interface between hydraulic-design and 3D modelling. A computational fluid dynamics code is used to investigate the flow characteristics and performance of the axial-flow pump. Numerical simulation is performed by adopting 3D RANS equations with RNG k-epsilon turbulence model. An unstructured grid system and the finite-volume method are used for the solution procedure of the discretized governing equations for this problem. The rotator-stator interaction is treated with a multiple reference frame (MRF) strategy. Computations are performed in different cases: 7 different relative circumferential angles (Δθ) between the inducer blade trailing edge and the impeller blade leading edge, 3 different axial gaps (G) between the inducer and the impeller. Variation of the hydraulic loss in the rotator is obtained with the change of delta theta. The numerical results show that the pressure generated is minimum in case of (G = 3%D). This indicates that the interference between inducer and impeller is strong if the axial gap is small. The pump performances are predicted and compared to the experimental measurements. The current investigation leads to a thorough enough understanding of the flow characteristics in axial-flow pumps with complex configurations. Recommendations for future modifications and improvements to the pump design are also given.
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Tang, Fang-Ping, Chao Liu, Ji-Ren Zhou, Hua Yang, and Li Cheng. "PIV Measurements and CFD Analysis in an Axial-Flow Pump." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37527.
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In this study, an axial flow pump impeller without guide vanes is experimentally investigated. The impeller used in the experiments consists of four blades. The particle image velocimetry technique and a five-hole probe have been used. Measurements of flow velocities in the outer part of the impeller have been made. PIV measurements have been realized in 12 meridian planes between blade-to-blade for design and off-design operating conditions. The meridian velocity is obtained with phase averaged method and the total circumferential mean velocity is obtained with an arithmetical average over the 12 circumferential data. The calculation is based on the CFX-TASC flow CFD code solving the three-dimensional Reynolds-averaged Navier-Stokes equation with RNG k–ε model of turbulence. The paper focuses on the comparisons of the results. Difference for the flow field between numerical and experimental results is small at large and design flow rate, while big difference occurs at small flow rate. It indicates that the numerical model is not suitable for separation flow.
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Shi, Lijian, Fangping Tang, Rongsheng Xie, Lilong Qi, and Zhengdong Yang. "Design Optimization of Axial-Flow Pump Blades Based on iSIGHT." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-02756.
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This paper research the influence of cascade dense degree and airfoil placed angle on hydralic performance of axial flow pump blades. Which combines the numerical optimization technology with the advanced CFD simulation technique, replaces designers’ experience by mathematical models for controlling of the blade design direction. Finally, a platform for of the optimization design of axial-flow pump blades is built in this paper. The platform which based on the multidisciplinary optimization software iSIGHT is to design and optimize the axial flow blades. The automatic optimization design platform for axial-flow blade was established, in which the parameterization modeling, mesh, flow computation and numerical optimization are combined together. The use of the numerical simulation software CFD for disciplinary analysis improved the reliability and accuracy of the results of the prediction model. Found the approximate geometric design parameters of the design conditions based on numerical simulation, and the technology of numerical optimization was used for constrained optimized analysis based on these parameters. Optimized impeller efficiency improved about 0.7% while satisfying the constraint condition, shows that the optimization method for axial flow blade base on iSIGHT platform is effective and feasible. Meanwhile, the optimization method can greatly shorten the design cycle, reduce design cost optimization.
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Li, Zhong, Minguan Yang, Can Kang, Bo Gao, and Kai Ji. "Experimental Study on Cavitating Flow in Impeller of Axial-Flow Pump." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-06070.
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Based on the external characteristic test, the performance of designed axial-flow model pump was determined. The cavitation performance of model pump at the best efficiency point was confirmed through the cavitation test. The cavitating flows in impeller at different NPSH values were shot by the high speed digital camera. MiVnt image analysis software was utilized to process the shooting images, track the cavitation region and outline of cavitation bubbles cluster. The experimental results show that the incipient cavitation regions are located in the inlet of blade suction surface near the tip and the leading edge of tip airfoil. With the decrease of NPSH values, the cavitation region at tip airfoil moves gradually from leading edge to trailing edge and the type of cavitation is vortex cavitation, its rotation axis direction is the same as circumferential direction. The cavitation region at blade suction surface indicates the same moving trend as at tip airfoil. The emerging of cloudy cavitation at the middle of blade suction surface indicates the beginning of pump cavitation. With the further increase of volume proportion of cavitation bubbles in impeller channel, the pump performance decreases severally. The experimental results reveal the preliminary laws of cavitating flow and provide an effective reference for the cavitation region and development process in impeller of axial-flow pump.
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Kang, Can, Qifeng Huang, and Yunxiao Li. "Influence of Vane Number on the Performance of Axial-Flow Pump Under Low-Flow-Rate Conditions." In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16331.
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In order to further probe the relations between hydraulic features and instantaneous vibration of impeller pump, an axial flow pump designed with different combination schemes of rotor and stator is numerically investigated. Vane numbers of 5, 7 and 9 are separately adopted to match the same impeller with 4 blades. Attentions are paid on the pump’s performance under low flow rates. Saddle-shaped performance curves are proved during the three pumps’ operation with the variation of flow rate. With pre-defined non-dimensional parameters, distributions of axial velocity near the impeller and vane are described. Pressure waves and wake in the region between impeller and vane influence significantly the turbulent flow patterns and energy dissipation. Typical frequencies achieved through fast Fourier transformation of fluctuating pressures also indicate that the emergence of low-frequency components and energy dissipation in the rotor-stator interaction (RSI) region arouse more non-deterministic factors of hydraulic excitation.
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Xiang, Hang, Jiang Chen, Jinxin Cheng, Han Niu, Yi Liu, and Xiancheng Song. "Aerodynamic Retrofit Design for a High Pressure Compressor Using a High Hub/Tip Ratio Mixed-Flow Compressor." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-15315.
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Abstract A high-load mixed-flow compressor with an extremely high inlet hub/tip ratio (0.889) is designed and analyzed for replacing the rear stages of a multistage high pressure axial compressor. The effects of blade number, splitter blades and dimensionless geometric parameters on the impeller performance are investigated by an improved loss model. A full-surface parameterization control method is adopted for blade optimizations of the mixed-flow impeller and the tandem stator. As a retrofit design of the multistage axial compressor, an unconventional type of axial-co-mixed-flow combined compressor scheme is proposed and discussed. Further, in order to minimize the axial dimension and maximize the load, this paper also proposed preliminary designs of the twin-stage mixed-flow compressor and the twin-stage counter-rotating mixed-flow compressor respectively equipped with the high hub/tip ratio mixed-flow compressor. The results indicate that the mixed-flow impeller configuration with 42 principal blades and splitter blades with a fifth of principal blade length has the maximum efficiency at design flow rate. Blade height/pitch ratio is a considerable parameter which demonstrates the interaction among hub/tip ratio, aspect ratio and solidity especially for high hub/tip ratio cascade designs. The mixed-flow compressor can greatly improve the load capacity of the high pressure compressor with slight impact on efficiency and surge margin. At low rotate speed, the mixed-flow impeller can maintain relatively high efficiency level and even carry a higher proportion of the load, while the tandem stator limits the overall efficiency improvement. Besides, structures with no return channel of the three unconventional combined compressors are beneficial to the reduction of dimension and cost, which shows the potential application prospects of high hub/tip ratio mixed-flow compressors.
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Senoo, Yasutoshi. "Mechanics on the Tip Clearance Loss of Impeller Blades." In ASME 1990 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1990. http://dx.doi.org/10.1115/90-gt-037.
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For predicting the tip clearance loss of turbomachines, different equations are published in the literatures based on differnt principles. In 1986 the present author posturated a new theory where the pressure loss consisted of two parts, one was the pressure loss induced by the drag force of the leaked flow and the other was the pressure loss to support the axial pressure difference without blades in the tip clearance zone. There were comments such as the two losses were the same loss looked from two different view points, or at least a part of the former was included in the latter or vice versa. In this paper the pressure loss due to the tip clearance is examined based on a macroscopic balance of forces and the two kinds of loss are derived. Furthermore, it is made clear that the former comes from the induced drag which is parallel to the blade while the latter comes from the missing blade force normal to the blade in the clearance zone. Because these two forces are mutually perpendicular, the two losses are entirely different in nature and they do not even partially overlap to each other. It is also made clear quantitatively, how the loss of the kinetic energy of leaked flow is related to the induced drag of the clearance flow.
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Shen, Xi, Desheng Zhang, Bin Xu, Yongxin Jin, and Xiongfa Gao. "Experimental and Numerical Investigation on Pressure Fluctuation of the Impeller in an Axial Flow Pump." In ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ajkfluids2019-5161.
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Abstract The Detached Eddy Simulation (DES) has been used to simulate the pressure fluctuation of the impeller in an axial flow pump. The results were combined with experiments including high-speed photography and transient pressure measurements to investigate the unstable flow induced by tip leakage vortex (TLV). Numerical results show that maximum predictive error values of head is 2.9%, compared with experimental results. The pressure fluctuation at different monitoring points present a certain regularity, with 3 peaks and 3 troughs in a period, corresponding to the number of blades. The amplitude of pressure fluctuation at P1 (impeller inlet) is the highest among those monitoring points, where the amplitude decreases with the flow rates. The dominant frequency of pressure fluctuation at impeller under cavitation condition is the blade passing frequency (BPF). Besides, there are also N* = 6, 9, 12 and other more harmonic frequencies. The cavitation flow was analyzed with the pressure fluctuation of the blade tip. For the existence of the pressure difference between pressure side and suction side, the pressure at monitoring points change alternately. The amplitude of the fluctuation near tip is affected seriously by the cavitation bubbles, as the cavitation could is a low pressure region with unstable fluctuation.