Discussion: “A Comparison of the Matrix and Streamline Curvature Methods of Axial Flow Turbomachinery Analysis, From a User’s Point of View” (Davis, W. R., and Millar, D. A. J., 1975, ASME J. Eng. Power, 97, pp. 549–558)

1975 ◽  
Vol 97 (4) ◽  
pp. 558-559
Author(s):  
D. Japikse
1975 ◽  
Vol 97 (4) ◽  
pp. 549-558 ◽  
Author(s):  
W. R. Davis ◽  
D. A. J. Millar

In recent years two general methods for flow analysis in turbomachinery have been developed, one generally called the Streamline Curvature Method, the other the Matrix Through-Flow Method. Both methods solve the same flow equations but the differences in technique introduce different operational constraints and difficulties. A comparative assessment of the relative merits of the two methods has been difficult because the various authors did not use similar cascade models to represent cascade loss and deviation, a necessary adjunct to each technique. This paper outlines the two methods, and a common cascade model for both, and compares two programs written to implement the two techniques for ease of use, computer time and storage requirements, flexibility and inherent limitations. The programs are used to compute the flow field in three axial flow compressor applications: an interconnecting duct, a transonic fan, and three stage axial compressor. The predicted performance for the above machines was fairly good, although no attempt was made to “tune” the cascade model for the specific type of machine, as the relative merits of each method were of interest. It is concluded that there is a small operational advantage to the matrix method.


Author(s):  
D. J. L. Smith ◽  
J. F. Barnes

In the last few years considerable progress has been made in calculating the three-dimensional flows through turbomachines. The two methods which appear to be widely used are what have come to be known as the “Streamline Curvature” and the “Matrix Through Flow” methods. At the National Gas Turbine Establishment, these advanced methods have been applied to existing turbomachines and this paper presents some of the calculated and experimental results for four axial flow machines. By making use of fairly simple loss distributions it has been found that these methods can assist towards the understanding of observed phenomena and, in the case of the axial compressor, they offer some prospect of being able to calculate the onset of surge. Also included is a brief report of work in progress to generate a computer program for the solution of the compressible velocity distribution around the surfaces of turbomachine blades, together with an indication of possible future experimental work.


Author(s):  
J. P. Gostelow ◽  
J. H. Horlock ◽  
H. Marsh

Work on subsonic compressors is reviewed and traditional British and American methods of design are compared. Transonic compressors are now well established and recent progress, demonstrating the necessity for properly shaped blades in machines having high tip speeds, is examined. Advances in the computer-aided design of turbomachinery are described: these include the ‘Matrix through-flow’ and ‘Streamline curvature’ methods of calculating the meridional flow. Experimental results give preliminary confirmation of a method of annulus wall boundary layer prediction. Finally, current and future developments are discussed and an attempt is made to describe how an axial flow compressor may be designed a decade hence.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Dionysios Anninos ◽  
Beatrix Mühlmann

Abstract We explore the conjectured duality between a class of large N matrix integrals, known as multicritical matrix integrals (MMI), and the series (2m − 1, 2) of non-unitary minimal models on a fluctuating background. We match the critical exponents of the leading order planar expansion of MMI, to those of the continuum theory on an S2 topology. From the MMI perspective this is done both through a multi-vertex diagrammatic expansion, thereby revealing novel combinatorial expressions, as well as through a systematic saddle point evaluation of the matrix integral as a function of its parameters. From the continuum point of view the corresponding critical exponents are obtained upon computing the partition function in the presence of a given conformal primary. Further to this, we elaborate on a Hilbert space of the continuum theory, and the putative finiteness thereof, on both an S2 and a T2 topology using BRST cohomology considerations. Matrix integrals support this finiteness.


2013 ◽  
Vol 592-593 ◽  
pp. 401-404
Author(s):  
Zdeněk Chlup ◽  
Martin Černý ◽  
Adam Strachota ◽  
Martina Halasova ◽  
Ivo Dlouhý

The fracture behaviour of long fibre reinforced composites is predetermined mainly by properties of fibre-matrix interface. The matrix prepared by pyrolysis of polysiloxane resin possesses ability to resist high temperatures without significant damage under oxidising atmosphere. The application is therefore limited by fibres and possible changes in the fibre matrix interface. The study of development of interface during high temperature exposition is the main aim of this contribution. Application of various techniques as FIB, GIS, TEM, XRD allowed to monitor microstructural changes in the interface of selected places without additional damage caused by preparation. Additionally, it was possible to obtain information about damage, the crack formation, caused by the heat treatment from the fracture mechanics point of view.


Author(s):  
K. Oliinyk

The article examines the specificity of existence of the renewed mystery genre as a meta genre in the twentieth century. The main literary study views on the definition of ancient and medieval / Christian ritual mystery are analyzed. The beginning of the twentieth century was full of a general feeling of catastrophe and tragic hopelessness. In artistic terms, the consequence of this was the activation of Christian issues, motives, plots, religious genres (miracles, morality and mystery). The most universal from the point of view of the ideological message and content for the writers of the twentieth century. was the matrix of the medieval mystery, which retained the ritual basis in its primary structure. This made it possible for the multilevel organization of the action and the space for it. The genre of medieval mystery is being modified, it ceases to be a purely form of religious action and acquires the quality of a meta genre. There is a transition from the religious sphere to the secular one, and the aesthetic one is replacing the didactic load. Mystery begins to exist on the edge of genres as a synthetic formation, showing intentions to “help” other genres. A large number of dramatic works of the twentieth century. ("Forest Song" by Lesia Ukrainka, "Iconostasis of Ukraine" by Vіra Vovk) comes close to the mystery, using its archetypal components: the ideas of faith in the absolute beginning, governing the eternal rotation of life and death, world order and harmony, death and rebirth, transformations of the human soul, chosenness and initiation associated with trials, sacrifice, deepening into mysticism. Such works are a certain imitation with elements of mythological or religious subjects. So, the twentieth century, actualizes a certain involvement of the semantic content of dramas to the mysteries, bringing the mystery to the level of the meta genre.


2015 ◽  
Vol 5 (1) ◽  
pp. 110-138
Author(s):  
Dmitry Ganenkov

The article investigates diachronic changes in infinitival complementation from Caucasian Albanian to modern Udi dialects. It describes the syntactic structure of infinitival complements in Caucasian Albanian, 19th century Vartashen Udi and two modern dialects, and concentrates on case marking of overt subjects in constructions with the matrix verbs ‘can, be able’, ‘begin’ and ‘want’. From a diachronic point of view, the data presented in the article allow us to conclude that historical changes in both the lexical form of complement-taking predicates and the morphology of their complements obey Cristofaro’s (2003) Complement Deranking Hierarchy.


Zootaxa ◽  
2018 ◽  
Vol 4457 (1) ◽  
pp. 179 ◽  
Author(s):  
LEIDYS MURILLO-RAMOS ◽  
RENZO HERNÁNDEZ TORRES ◽  
RAYNER NÚÑEZ ÁGUILA ◽  
ROGER AYAZO

Phoebis Hübner (1819) is a genus of the Neotropical subfamily Coliadinae (Lepidoptera: Pieridae). The highest diversity is found in the Greater Antilles islands in the Caribbean region. Although from the taxonomic point of view, Phoebis seems to be a stable genus, there is no phylogenetic hypothesis corroborating the monophyly of the genus. In this study, we used both morphological characters and a genetic dataset consisting of one mitochondrial (COI) and three nuclear markers (RpS5, MDH, Wingless). The matrix was concatenated and analysed with parsimony under implied weights (IW). Also, the concatenated data set was analysed using maximum likelihood and Bayesian inference evolutionary methods, and ancestral states reconstruction with characters traditionally used for classification of Phoebis was carried out. The same topology was recovered by Parsimony, ML and BI analysis, and suggest that Phoebis is not a monophyletic genus, with Aphrissa and Rhabdodryas nested within it. Our findings allow us to consider the genera Rhabdodryas syn.rev. and Aphrissa syn.rev. to be synonyms of Phoebis. These results have implications for the systematics of Phoebis and the genera that should be accepted in Coliadinae.


2011 ◽  
Vol 187 ◽  
pp. 251-256
Author(s):  
Lei Wang ◽  
Tian Rui Li ◽  
Jun Ye

The essence of the rough set theory (RST) is to deal with the inconsistent problems by two definable subsets which are called the lower and upper approximations respectively. Asymmetric Similarity relation based Rough Sets (ASRS) model is one kind of extensions of the classical rough set model in incomplete information systems. In this paper, we propose a new matrix view of ASRS model and give the matrix representation of the lower and upper approximations of a concept under ASRS model. According to this matrix view, a new method is obtained for calculation of the lower and upper approximations under ASRS model. An example is given to illustrate processes of calculating the approximations of a concept based on the matrix point of view.


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