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Статті в журналах з теми "Meridional shape"
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Wang, Yan, Quanlin Dong, and Yulian Zhang. "Meridional shape design and the internal flow investigation of centrifugal impeller." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 23 (August 30, 2016): 4319–30. http://dx.doi.org/10.1177/0954406216667407.
Повний текст джерелаАнотація:
This paper describes an inverse design method for calculating the shape of meridional plane of centrifugal impeller. This design method permits the shroud and hub contours to be indirectly calculated by medial axis contour and constraint equations. The design process is computationally inexpensive and can conveniently modify the shroud and hub shapes as the design’s demand. Based on this design method, new constraint equations are used for a new shape design of meridional plane that lead to a uniform velocity distribution in the inlet of impeller. Numerical simulations are employed to investigate the fluid flows of centrifugal fan. After validation of the numerical strategy, the pressure and velocity distributions in centrifugal fan are illustrated. The numerical results show that the inlet performance is improved and the velocity distribution is more uniform. Furthermore, in order to understand the flow mechanism inside the centrifugal fan, the secondary flow in the blade passage and velocity distribution at the shroud and hub have been carried out a detailed investigation and study.
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Ragen, Sarah, Kyle C. Armour, LuAnne Thompson, Andrew Shao, and David Darr. "The Role of Atlantic Basin Geometry in Meridional Overturning Circulation." Journal of Physical Oceanography 52, no. 3 (March 2022): 475–92. http://dx.doi.org/10.1175/jpo-d-21-0036.1.
Повний текст джерелаАнотація:
Abstract We present idealized simulations to explore how the shape of eastern and western continental boundaries along the Atlantic Ocean influences the Atlantic meridional overturning circulation (AMOC). We use a state-of-the art ocean–sea ice model (MOM6 and SIS2) with idealized, zonally symmetric surface forcing and a range of idealized continental configurations with a large, Pacific-like basin and a small, Atlantic-like basin. We perform simulations with five coastline geometries along the Atlantic-like basin that range from coastlines that are straight to coastlines that are shaped like the coasts of the American and African continents. Changing the Atlantic basin coastline shape influences AMOC strength in a manner distinct from simply increasing basin width: widening the basin while maintaining straight coastlines leads to a 10-Sv (1 Sv ≡ 106 m3 s−1) increase in AMOC strength, whereas widening the basin with the geometry of the American and African continents leads to a 6-Sv increase in AMOC strength, despite both cases representing the same average basin-width increase relative to a control case. The structure of AMOC changes are different between these two cases as well: a more realistic basin geometry results in a shoaled AMOC while widening the basin with straight boundaries deepens AMOC. We test the influence of the shape of the both boundaries independently and find that AMOC is more sensitive to the American coastline while the African coastline impacts the abyssal circulation. We also find that AMOC strength and depth scales well with basin-scale meridional density difference, even with different Atlantic basin geometries, illuminating a robust physical link between AMOC and the North Atlantic western boundary density gradient.
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Miyauchi, Sunao, Hironori Horiguchi, Jun-ichirou Fukutomi, and Akihiro Takahashi. "K-1102 Optimization of Meridional Shape Design of Pump Impeller." Proceedings of the JSME annual meeting II.01.1 (2001): 25–26. http://dx.doi.org/10.1299/jsmemecjo.ii.01.1.0_25.
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Chen, Xin, Linlin Cao, Peng Yan, Peng Wu, and Dazhuan Wu. "Effect of meridional shape on performance of axial-flow fan." Journal of Mechanical Science and Technology 31, no. 11 (November 2017): 5141–51. http://dx.doi.org/10.1007/s12206-017-1008-1.
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Talon, Suzanne, Georges Michaud, and Alain Vincent. "On meridional Circulation in Stars." Symposium - International Astronomical Union 198 (2000): 498–99. http://dx.doi.org/10.1017/s0074180900167154.
Повний текст джерелаАнотація:
Even though the existence of meridional currents in stars has been known for quite a long time (Eddington 1925, Vogt 1925), its exact structure as well as its influence on stellar evolution is still unclear. Some authors concentrated on finding the exact shape of meridional circulation in a rotating star, while others tried to model its effect on the chemical distribution in the interior. In all studies performed so far however, meridional circulation is considered in an asymptotic regime in which the advection of entropy by the meridional currents is supposed to balance exactly the source term of the non-zero radiative flux divergence. Other terms could however be added to that asymptotic regime which could turn out to dominate the transport of chemicals. We wish to present here preliminary results of 3D numerical simulation attempted to tackle this problem.
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Miyauchi, Sunao, Hironori Horiguchi, Jun-ichirou Fukutomi, and Akihiro Takahashi. "Optimization of Meridional Flow Channel Design of Pump Impeller." International Journal of Rotating Machinery 10, no. 2 (2004): 115–19. http://dx.doi.org/10.1155/s1023621x04000120.
Повний текст джерелаАнотація:
The meridional flow channel design of a pump impeller affects its performance. However, since so many design parameters exist, a new design method is proposed in which a meridional and blade-to-blade flow channel is designed by the parallel use of the circulation distribution provided by the designer. Thus, an optimization method was used to design an axis-symmetrical meridional flow channel from the circulation distribution. In addition, the inverse design method proposed by Zangeneh et al. (1996) was employed to design a three-dimensional blade-to-blade flow channel from the circulation distribution and the optimized meridional shape. In this article, a few design examples and these Computational Fluid Dynamics (CFD) validations are also given.
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Kim, Sung, Young-Seok Choi, Kyoung-Yong Lee, and Jun-Ho Kim. "Design Optimization of Mixed-flow Pump in a Fixed Meridional Shape." International Journal of Fluid Machinery and Systems 4, no. 1 (March 31, 2011): 14–24. http://dx.doi.org/10.5293/ijfms.2011.4.1.014.
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Kvasha, Yu A., and N. A. Zinevych. "On the effect of the meridional contour shape on the power characteristics of a centrifugal compressor wheel." Technical mechanics 2020, no. 3 (October 15, 2020): 12–17. http://dx.doi.org/10.15407/itm2020.03.012.
Повний текст джерелаАнотація:
This work is concerned with the development of approaches to the optimal aerodynamic design of centrifugal compressor wheels, which is due to the use of centrifugal stages in compressors of modern aircraft gas turbine engines and power plants. The aim of this work is a computational study of the effect of the meridional contour shape of a centrifugal compressor wheel on its power characteristics. The basic method is a numerical simulation of 3D turbulent gas flows in centrifugal wheels on the basis of the complete averaged Navier¬–Stokes equations and a two-parameter turbulence model. The computational study features: varying the shape of the hub and tip part of the meridional contour over a wide range, formulating quality criteria as the mean integral values of the wheel power characteristics over the operating range of the air flow rate through the wheel, and a systematic scan of the independent variable range at points that form a uniformly distributed sequence. As a result of multiparameter calculations, it was shown that in the case of a flow without separation in the blade channels of a wheel with a given starting shape of the meridional contour, varying that shape has an insignificant effect on the wheel power characteristics. It is pointed out that in similar cases it seems to be advisable to aerodynamically improve centrifugal wheels by varying the shape of their blades in the circumferential direction rather than in the meridional plane. This conclusion was made using rather a “coarse” computational grid, which, however, retains the sensitivity of the computed results to a variation in the centrifugal wheel geometry. On the whole, this work clarifies ways of further aerodynamic improvement of centrifugal compressor impellers in cases where the starting centrifugal wheel is a well-designed wheel with a flow without separation in the blade channels. The results obtained may be used in the aerodynamic optimization of centrifugal stages of aircraft gas turbine engines.
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Lutsko, Nicholas J., and Isaac M. Held. "The Response of an Idealized Atmosphere to Orographic Forcing: Zonal versus Meridional Propagation." Journal of the Atmospheric Sciences 73, no. 9 (August 26, 2016): 3701–18. http://dx.doi.org/10.1175/jas-d-16-0021.1.
Повний текст джерелаАнотація:
Abstract A dry atmospheric general circulation model is forced with large-scale, Gaussian orography in an attempt to isolate a regime in which the model responds linearly to orographic forcing and then to study the departures from linearity as the orography is increased in amplitude. In contrast to previous results, which emphasized the meridional propagation of orographically forced stationary waves, using the standard Held–Suarez (H–S) control climate, it is found that the linear regime is characterized by a meridionally trapped, zonally propagating wave. Meridionally trapped waves of this kind have been seen in other contexts, where they have been termed “circumglobal waves.” As the height of the orography is increased, the circumglobal wave coexists with a meridionally propagating wave and for large-enough heights the meridionally propagating wave dominates the response. A barotropic model on a sphere reproduces this trapped wave in the linear regime and also reproduces the transition to meridional propagation with increasing amplitude. However, mean-flow modification by the stationary waves is very different in the two models, making it difficult to argue that the transitions have the same causes. When adding asymmetry across the equator to the H–S control climate and placing the orography in the cooler hemisphere, it becomes harder to generate trapped waves in the GCM and the trapping becomes sensitive to the shape of the orography. The barotropic model overestimates the trapping in this case. These results suggest that an improved understanding of the role of circumglobal waves will be needed to understand the stationary wave field and its sensitivity to the changes in the zonal-mean climate.
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Biggs, James D. "Meridional Compression of Radio Pulsar Beams." International Astronomical Union Colloquium 128 (1992): 22–25. http://dx.doi.org/10.1017/s0002731600154691.
Повний текст джерелаАнотація:
AbstractWe have studied the radio pulsar emission beam assuming a) a magnetic dipole field geometry and b) that the beam geometry is defined by the field lines that are not contained within the light cylinder. In general, the beam is compressed in the meridional direction. When the magnetic and rotation axes are aligned the beam is circular and as, the angle between these axes increases, the ratio of meridional to longitudinal dimension decreases monotonically to the minimum value 0.62 when the axes are orthogonal. This beam shape is thus consistent with that inferred from the study of circular polarization in average pulse profiles by Radhakrishnan and Rankin. Evidence for meridional compression is also found in the extensive observational study of Lyne and Manchester (1988).The beam evolution was determined using this data set, the beamwidth being found proportional to P–1/2, where P is the pulsar period. This relation implies that the more rapidly rotating pulsars should have larger beams, and this should aid in their detection. The more numerous, slower pulsars should have somewhat smaller beams than previously determined. This implies that the pulsar birthrate is probably close to the highest current estimates (1 in 25yr).
Дисертації з теми "Meridional shape"
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Баранник, Валентин Сергеевич. "Пространственная аэродинамическая оптимизация направляющей решетки осевой турбины". Thesis, НТУ "ХПИ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/22677.
Повний текст джерелаАнотація:
Диссертация на соискание ученой степени кандидата технических наук по специальности 05.05.16 – турбомашины и турбоустановки. – Национальный технический университет "Харьковский политехнический институт", Харьков, 2016. Диссертация посвящена разработке методики пространственной аэродинамической оптимизации направляющих решеток осевых турбин путем поиска оптимальных формы профилей и меридиональных обводов межлопаточных каналов. Использование данной методики позволяет при решении оптимизационной задачи учесть дополнительные резервы повышения эффективности. Поиск оптимального варианта осуществлялся с использованием теории планирования эксперимента и ЛПτ – последовательности. Для описания полимодальных целевых функций исходная формальная макромодель в виде полного квадратичного полинома была уточнена путем замены суперпозиции параболы на суперпозицию кубического интерполяционного сплайна. На основе разработанной методики проведена оптимизация направляющей решетки третьей степени мощной паровой турбины с постоянным по высоте профилем при построении его различными типами кривых. Анализ результатов оптимизации показал, что наибольшее снижение интегральных потерь составило 7% в относительных величинах. Снижение потерь было достигнуто, как в ядре потока, так и в области вторичных течений. Существенно влиять на структуру течения в турбинных решетках, а следовательно получать дополнительных выигрыш при постановке оптимизационной задачи позволяет меридиональное профилирование поверхностей межлопаточного канала. Оптимизация периферийного меридионального обвода с помощью разработанного метода позволила дополнительно снизить интегральные потери 1,4%. в относительных величинах. Построение формы меридионального обвода осуществляется с использованием кривых Безье 4-го порядка для решеток без раскрытия и 3-го порядка – для решеток с раскрытием. Использование лопатки переменного по высоте профиля при постановке оптимизационной задачи также позволяет снизить интегральные потери.Thesis for degree of Candidate of Sciences in Technique for speciality 05.05.16 – turbomachine and turbo-installation. – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2016. The thesis is devoted to development the methods of the three-dimensional aerodynamic optimization of axial turbine nozzle cascades by defining the optimal shape of profiles and nozzle channel meridional shape. The formulation of an optimization problem using this methods allows to consider the additional efficiency reserves.While implementing developed method design of the turbine profiles using different kinds of curves was carried out. For each of the curve types the control parameters that allow to widely vary the profile geometry were determined. The results reliability was confirmed by providing verification of the nozzle and blade cascade simulations with experimental data. Using developed methods the optimization of the third stage nozzle cascade with a constant height profile of the powerful steam turbine using different types of curves was conducted. As a result of optimization the largest reduction of the integral losses by 7% in relative values was shown. Further optimization of the shroud meridional shape using developed optimization method increased this value by 1.4%. Formulation optimization task Using variable nozzle height profile also reduces the integral loses.
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Бараннік, Валентин Сергійович. "Просторова аеродинамічна оптимізація направляючої решітки осьової турбіни". Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/22676.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.16 – турбомашини та турбоустановки. – національний технічний університет "Харківський політехнічний інститут", Харків, 2016. Дисертація присвячена розробці методики просторової аеродинамічної оптимізації напрямних решіток осьових турбін шляхом пошуку оптимальних форми профілів та меридіональних обводів міжлопаткових каналів. Використання даної методики дозволяє при постановці оптимізаційної задачі врахувати додаткові резерви підвищення ефективності. При реалізації цієї методики було виконано проектування турбінних профілів з використанням різного роду кривих. Для кожного типу кривої визначені її параметри управління, що дозволяють в широких межах варіювати геометрію профілю. Достовірність отриманих результатів підтверджується проведеною верифікацією на направляючій та робочій решітці. На основі розробленої методики проведено оптимізацію направляючої решітки третього ступеня потужної парової турбіни з постійним по висоті профілем при побудові його різними типами кривих. Аналіз результатів оптимізації показав, що найбільше зниження інтегральних втрат склало 7% у відносних величинах. Подальша оптимізація периферійного меридіонального обводу за допомогою розробленого методу дозволила збільшити цю величину на 1,4%. Використання лопатки перемінного по висоті профілю при постановці оптимізаційної задачі також дозволяє знизити інтегральні втрати.Thesis for degree of Candidate of Sciences in Technique for speciality 05.05.16 – turbomachine and turbo-installation. – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2016. The thesis is devoted to development the methods of the three-dimensional aerodynamic optimization of axial turbine nozzle cascades by defining the optimal shape of profiles and nozzle channel meridional shape. The formulation of an optimization problem using this methods allows to consider the additional efficiency reserves.While implementing developed method design of the turbine profiles using different kinds of curves was carried out. For each of the curve types the control parameters that allow to widely vary the profile geometry were determined. The results reliability was confirmed by providing verification of the nozzle and blade cascade simulations with experimental data. Using developed methods the optimization of the third stage nozzle cascade with a constant height profile of the powerful steam turbine using different types of curves was conducted. As a result of optimization the largest reduction of the integral losses by 7% in relative values was shown. Further optimization of the shroud meridional shape using developed optimization method increased this value by 1.4%. Formulation optimization task Using variable nozzle height profile also reduces the integral loses.
Частини книг з теми "Meridional shape"
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Rova, Elena. "Usi funerari nel Caucaso Meridionale nell'Età del Bronzo Antico: il caso di Shida Kartli (Georgia)." In Eurasiatica. Venice: Edizioni Ca' Foscari, 2019. http://dx.doi.org/10.30687/978-88-6969-340-3/001.
Повний текст джерелаАнотація:
Based on the results of recent investigations, the paper discusses the transformation of funerary customs from the 4th to the end of the 3rd millennium BC in the Shida Kartli region of Georgia. In contrast with both the previous and the following phase, the Kura-Araxes culture is characterised by a weak differentiation in burial goods. The transition to the following Early Kurgan period, when wealthy individual graves in the shape of large barrows become common, appears to have been less sharp in Shida Kartli than elsewhere, and possibly mediated by the appearance of large collective pit graves. Hybridisation phenomena between Kura-Araxes and Early Kurgan funerary customs can also be observed.
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Polyak, Ilya. "The GCM Validation." In Computational Statistics in Climatology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195099997.003.0009.
Повний текст джерелаАнотація:
In this chapter the observed and simulated (by the Hamburg GCM) Northern Hemisphere monthly surface air temperatures, averaged within different latitude bands, are statistically analyzed and compared. The objects used for the analysis are the two-dimensional spatial-temporal spectral and correlation characteristics, the multivariate autoregressive and linear regression model parameters, and the diffusion equation coefficients. A comparison shows that, generally, the shapes of the corresponding spectra and correlation functions are quite similar, but their numerical values and some features differ markedly, especially for the tropical regions. The spectra reveal a few randomly distributed maxima (along the frequency axis), the periods of which were not identical for both types of data. A comparative study of the estimates of the diffusion equation coefficients shows a significant distinction between the character of the meridional circulations of the observed and simulated systems. The approach developed gives approximate stochastic models and reasonable descriptions of the temperature processes and fields, thereby providing an opportunity for solving some of the vital problems of theoretical and practical aspects surrounding validation, diagnosis, and application of the GCM. The methodology and results presented make it clear that formalization of the statistical description of the surface air temperature fluctuations can be achieved by applying the standard techniques of multivariate modeling and multidimensional spectral and correlation analysis to the data which have been averaged spatially and temporally. The idea of the statistical approach to the problems of GCM variability validation is contained in the comparison (observed vs. modeled) of the probability distributions of the different atmospheric and ocean processes and fields. At first, such a statement sounds like a standard statistical approach, and its solution would be obvious and simple if the number of climate processes taking place jointly were not huge and if they did not present a tremendously complicated (in its interrelationships and feedbacks) deterministic-stochastic system. As is known, the Stochastic System Identification Theory (see Eikhoff, 1983) deals mostly with the methodology for identifying linear systems, The interdependences of climatic processes and fields are not linear, and the application of this theory can give only highly approximate results.
Тези доповідей конференцій з теми "Meridional shape"
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Xu, Cheng, and R. S. Amano. "Centrifugal Compressor Design Impacts: Lean and Meridional Shape." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94111.
Повний текст джерелаАнотація:
Optimization procedures are widely used in centrifugal compressor developments to enable high efficiency and wide operating ranges of compressors. It is very important to understand how to set the parameters and which parameter needs to be optimized. This paper demonstrates a case study on the importance of mechanical and structure combination optimization and also discusses the meridional impacts of compressor performance. Recently, the high pressure ratio and the efficiency of centrifugal compressors require impeller designs to pay attention to multi-disciplinary optimization. High efficiency and a wide operation range are always the design goal. The geometry of the blades and the meridional profile are very important contributors to compressor performance and structure reliability. Therefore, it is critical to consider all aspects of compressor optimization. The goal of currently used centrifugal compressors is to design a compressor with the same back-disc diameter with the best efficiency and the highest-pressure ratio.
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Zangeneh, M. "On the Inverse Design of Inter-Stage Ducts, Diffuser Walls and Meridional Geometry of Turbomachines." In ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-208.
Повний текст джерелаАнотація:
In this paper a method is presented for the design of diffuser walls, interstage ducts and meridional geometry of turbomachines. In this method the wall geometry is designed subject to a specified meridional velocity distribution. The effect of variations in inlet velocity (or inlet shear flow) to the duct is modelled by using a vorticity term related to spanwise variations in stagnation enthalpy and the drift function. The flow field is then solved by using a streamfunction and a kinematic condition based on the vorticity in the flow. A simple transpiration model is used to update the wall geometry. To design the meridional geometry of turbomachines a vorticity related to bound circulation is introduced. This vortex term together with the inviscid slip condition can be used to find the swirl distribution when blade shape is specified (blade analysis mode) or the blade shape when the swirl distribution is specified (blade design mode). The results of the application of the method to a converging duct, an S-shaped duct with non-uniform inlet flow and the meridional geometry of a centrifugal compressor impeller confirm the validity of this approach.
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Kim, Sung, Young-Seok Choi, Kyoung-Yong Lee, M. A. Wahid, S. Samion, N. A. C. Sidik, and J. M. Sheriff. "Design Optimization of Mixed-flow Pump Impellers and Diffusers in a Fixed Meridional Shape." In THE 10TH ASIAN INTERNATIONAL CONFERENCE ON FLUID MACHINERY. AIP, 2010. http://dx.doi.org/10.1063/1.3464868.
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Paßrucker, H., and R. A. Van den Braembussche. "Inverse Design of Centrifugal Impellers by Simultaneous Modification of Blade Shape and Meridional Contour." In ASME Turbo Expo 2000: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/2000-gt-0457.
Повний текст джерелаАнотація:
A numerical procedure for the design of a centrifugal compressor impeller with prescribed isentropic Mach number distribution along the blade suction and pressure side is described. Both the blade shape and the endwalls are defined at the same time. This method is a combination of a 3D and a quasi-3D flow analysis programs with a quasi-3D geometry modification algorithm. The 3D analysis program is used for a given impeller geometry to calculate the velocity distribution along the blade. The difference between the desired velocity at pressure and suction side and the one calculated by the 3D analysis program for the actual geometry, is used to calculate the required modification of the mean velocities and swirl in the flow. These values are added to the values given by the quasi-3D analysis program to define the new quasi-3D target used for the modification of the geometry. The endwalls are designed with the transpiration method so that a prescribed distribution of mean velocity at hub and shroud is reached. The blade shape is modified until a prescribed swirl distribution is obtained. An iterative use of these programs results in a geometry for which the calculated 3D velocity is equal or as close as possible to the desired one. The practical application of this procedure to the design of centrifugal compressor impellers is illustrated by an example.
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Pagar, Nitin D., and S. H. Gawande. "Experimental Investigations on Meridional and Circumferential Stresses of Bellows due to Internal Pressure." In ASME 2019 Gas Turbine India Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gtindia2019-2771.
Повний текст джерелаАнотація:
Abstract Bellows Expansion joints are mostly linked with the piping connections of turbines, heat exchangers, process equipment’s etc. Its primary function is to absorb expansion and contraction in pipelines on which it is fixed and fulfill its functioning through peculiar springy shaped convolutions. At design stage, it is very difficult to guess fatigue life cycles due to evolved stresses in convolutions. When it is subjected to purely axial load, stress generation per convolution acting along longitudinal line is same; however the behavior is different under very small angular rotation and axial shift due to misalignments in structural mountings. To understand it, preliminary investigations on axial case is necessary and also to identify the location of various stresses in convoluted section. This work aims to determine the meridional and circumferential stresses on the convoluted shape when it is subjected to an axi-symmetric internal pressure loading. Experimentation is carried out to determine the maximum stresses and verified it with the help of numerical simulation and analytically. 10 convolution bellows is used for the experiments. It is observed that the meridional stresses are highly dominating the circumferential stresses along the same longitudinal line. Meridional membrane stresses and meridional bending stresses due to pressure are evaluated on two different locations, one on perfectly meridional line and another at the top surface of convolution along the same longitudinal line. The stresses found higher on the top surface of convolutions. Meridional membrane and bending stresses due to deflection are higher than the meridional membrane and bending stresses due to pressure. Evaluation of the maximum stresses is very helpful for the designers to develop the fatigue analysis model and exact prediction of the cycle life of the bellows.
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Ratter, H., Ş. Çağlar, and M. Gabi. "A Coupled Blade Adjustment and Response Surface Method for the Optimization of Radial Fans Without Housing." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25564.
Повний текст джерелаАнотація:
The optimization process of a fan based on 3D viscous CFD calculations is time consuming, especially if many variables are taken into account. With the focus on computational cost efficiency and reliable CFD-results a specific optimization algorithm for radial fans based on CFD calculations is presented. The algorithm is derived from the classical knowledge of flow phenomena occurring in radial fans. The leading edge is adjusted in reference to the stagnation point caused by the incoming flow. The trailing edge is adjusted to achieve the required pressure rise. The 5 blades of the investigated fan are constructed as 3D free surface blades; each blade is separated into 5 profile sections. The optimization process regarding the blade includes 10 independent parameters of the leading and trailing edges. An additional potential to increase efficiency is obtained by changing the meridional shape of the impeller. To investigate the meridional shape, the blade adjustment algorithm is coupled with a response surface method using the Kriging approximation to find a highly efficient meridional shape.
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Shim, Hyeon-Seok, and Kwang-Yong Kim. "EFFECTS OF MERIDIONAL SHAPE ON HYDRAULIC AND SUCTION PERFORMANCE OF A HIGH SPECIFIC SPEED CENTRIFUGAL PUMP." In 3rd Thermal and Fluids Engineering Conference (TFEC). Connecticut: Begellhouse, 2018. http://dx.doi.org/10.1615/tfec2018.cmd.021436.
Повний текст джерела
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Afanasiev, I. V., A. V. Granovski, A. M. Karelin, and M. K. Kostege. "Effect of 3D Vane Shape on the Flow Capacity." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53095.
Повний текст джерелаАнотація:
The results of the numerical analysis of the flow capacity and other parameters at the different turbine vanes are presented in this paper. Two plane cascades with the same geometrical throat but with a different shape of suction surface have been investigated by means of the 2D Navier-Stokes code [1]. Stacked with these profiles two vane rows with tip meridional opening have been investigated by means of the 3D Euler code [2] and the 3D Navier-Stokes code [3]. The numerical investigation of two full-scale annular vane rows is confirmed by experimental mass flow performance, obtained in a range of exit isentropic Mach number on the mean diameter from Ma2 is = 0.7 to Ma2 is = 1.3.
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Tuccillo, Raffaele, and Adolfo Senatore. "A Study on the Blade Shape Influence on Flow Distribution and Performance in Centrifugal Compressor Rotors." 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-099.
Повний текст джерелаАнотація:
The authors present an analysis of the flow through a centrifugal compressor rotor. A quasi-3D flow model evaluates the interaction of the meridional and blade-to-blade solution, so as to determine the flow pattern inside an inviscid region. A further interaction is then considered between the non-viscous flow and the boundary layers which grow along the end-walls and the blade surfaces. This makes it possible both to determine a more realistic flow condition, because of the blockage effects exerted by the boundary layers, and to estimate the total pressure losses related to the momentum thickness. Examples are presented for a compressor of an aircraft engine. The influence of blade shape on the above described phenomena is analyzed, starting from the actual rotor geometry and making a parametric study of the alterations in flow pattern produced by changes in meridional blade shape, inlet and outlet flow areas, and splitter blades. The analysis will provide a basis for future activities involving the use of optimizing techniques for the final choice of the blade characteristics.
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Zhang, Jinya, Hongwu Zhu, and Huan Wei. "Three-Dimensional Blade Design of Helico-Axial Multiphase Pump Impeller Based on Numerical Solution of Meridian Flow Net and Blade Mean Camber Lines." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-06030.
Повний текст джерелаАнотація:
The three-dimensional blade design method is adopted to design the blades of the impeller of a helico-axial multiphase pump. In this design method, the flow field of the impeller is computed with the hypothesis of multiphase homogeneous flow on the basis that it is the practical flow regime in the multiphase pump. The shape of the blade is obtained from a numerical solution of the meridian flow net the on meridional plane and blade mean camber lines on stream-surfaces of revolution. First, the contour shape and size of the meridian flow channel of the impeller blade is determined by parameterization design. Second, according to the discrete data of the contour shape, the meridian streamlines are determined by iterative computation based on solving the gas-liquid two phase meridional velocity gradient equation and the two phase coupled equations with quasi-orthogonals, and the flow parameters of the meridian flow net are computed simultaneously in order that the characteristics of the meridian fluid flow can be determined. And then the distribution of velocity moments can be obtained further. Third, the blade mean camber line equation is integrated with the point-by-point integral method, and then the blade mean camber line on the stream-surface of revolution which corresponds to every meridian streamline is obtained in order to form the shape of the impeller blade surface. At last, the meridional blade elements, which are the intersecting curves of blade shape surface with several meridional planes at different angles, and the variation of blade thickness, are determined. After that, the solid modeling of the three-dimensional blade of the impeller is formed. In addition, the characteristics of the flow field of the impeller and the performance of the multiphase pump are computed by CFD numerical simulation. The position where air blocking is tends to occur was analyzed on the basis of the result of numerical simulation.