CFD investigation of flow through a centrifugal compressor diffuser with splitter blades

The aerodynamic losses in centrifugal compressors are mainly associated with the separated flow on the suction sides of impeller and diffuser vanes. The overall performance of such compressors can be improved by adding splitter vanes. The present work examines the effect of varying the geometrical location of the splitter vanes in the diffuser on the overall performance of a high-speed centrifugal compressor stage of a small gas turbine. To increase the pressure recovery through the diffuser, two radial sets of vanes are used. The first set of vanes (diffuser-1) is equipped with splitter vanes, placed mid-distance between the main vanes, while the vanes of the second set (diffuser-2) are conventional vanes. Flow through the compressor was simulated using the ANSYS 19 workbench program. Flow characteristics and compressor performance were obtained and analyzed for different circumferential positions of the splitting vanes relative to the main vanes of diffuser-1. The study covered seven positions of the splitter vanes including the original design of the diffuser where the splitter vanes were located at mid-distance between the main vanes. The analysis shows that, at design conditions, selecting the position of the splitter vanes to be nearer to the pressure side of the main vanes improves the stage performance. In the present study, locating the splitters at 33% of the angular distance between the main vanes leads to the best performance, and a significant improvement in the overall stage performance is recorded. The pressure recovery coefficient is raised by about 17%, the pressure ratio is increased by about 1.13%, and the stage efficiency is increased by about 2.01%, compared to the original splitter position. Performance improvement is related to the suppression of the flow separation and the more uniformity of flow. On the contrary, further moving the splitter closer to the main blade, the pressure recovery coefficient is decreased by about 2% than the position of 33% of the angular distance, but still higher than the original position by about 15% and a limited improvement in the compressor performance is noticed. Moving the splitter far out the main blade annihilates the static pressure recovery of the diffuser by about 2:7% compared with the original position. So, for the investigated compressor, the best position of the splitter blade in the circumferential direction, which provides the best stage performance in our parametric analysis, is not necessary to be at the mid-angular distance between the diffuser’s main blades, but it is achieved by moving the splitter to about 33% of the angular distance where the diminished loss from the suppressed flow separation is more prevailing and the instigated friction losses from splitter surfaces are less critical.

ON THE IMPLEMENTATION OF THE A. BLOK’S POETRY IN THE SYMPHONIC SCORE OF B. TISHCHENKO'S BALLET THE TWELVE

The article examines the relationship between music and poetry in the ballet The Twelve by the outstanding Russian symphonist of the second half of the XX century Boris Ivanovich Tishchenko (1939–2010). The performance by the famous choreographer L. Yakobson, staged at the Kirov Theater in Leningrad in 1964, became one of the first avant-garde ballets in the Soviet Union. The study focuses on the different approaches of the composer and choreographer to the stage performance of A. Blok's poetry, which led to serious creative disagreements and even conflicts during the preparation of the premiere. Tishchenko in his reading relied on Blok's verse, its rhythm, size and complex, sometimes unexpected semantics. The speech beginning in The Twelve is quite tangible, the composer often follows Blok's lines literally. They now and then emerge in the flow of music, controlling it not only in the figurative-semantic and plot plans, but also in the rhythmic-intonation. The article concludes that Tishchenko's work has led to an impressive artistic result: the ballet score is written in a fresh, original and modern language. Tishchenko's music became the basis of the first avant-garde Soviet ballet performance and, in this context, firmly entered the history of Russian art

Stage Performance and Musical Analysis of Haacaaluu Hundeessaa Works by using Sentiment Analysis Techniques

This research is initiated to analysis the stage performance and musical analysis of Haacaaluu Hundeessaa works on Afaan oromoo reviews text collected from social Medias by applying the concept of sentiment analysis techniques. The data (reviews) were collected manually from social media on Haacaaluu Hundeessaa musical works. Haacaaluu Hundeessaa is Oromo singer, songwriter, civil rights activist and his being a voice his people. He is the most famous young singer, hero and icon of Oromo musician. From his musical works Sanyii Mootii(Race of the King), Waa'ee Keenyaa(Our Plight), Maalan Jira(What existence is mine), JIRTUU? are the most popular known in Oromo peoples as well as nation and nationality of Ethiopia. From Hacaaluu musical works, the researcher considered reviews (opinions) afaan oromoo text data on his single sang “JIRTUU?” to analysis stage performance of Haacaaluu Hundeessaa’s. The researcher inspires to use this single sang because; reviews (comments) are easier to access, available on you tube channel, extensive in size relatively from other his songs from social media. Additionally this song was broadcast live by Oromia Broadcasting Network and other Medias on different stage. Opinion lexicon approach with contextual valence shifter is used for analyzing opinions (comments) given on stage performance of Haacaaluu Hundeessaa works. Totally 18,687 reviews opinions or sentences were collected for experimentations to analysis stage performance and musical works of Haacaaluu Hundeessaa. Accordingly our result indicates around 99.52 percents peoples likes the stage performance and musical works of Hacaaluu Hundeessaa. From the results researcher observed Haacaaluu Hundeessaa has good performer with sing emotional and physically when he sing on the stages. In future works, further research needs to study others musical works of Hacaaluu Hundeessaa.

”Dette skulle bli et dikt som noen skulle huske en stund”

”This was supposed to become a poem which someone would remember for a while”: Stage Art as Poetry for Children in the Theatre Performance Snutebiller, stankelben Abstract: Norwegian author Rolf Jacobsen’s (1907–1994) modernist poetry, originally published for adults, has been celebrated for its boldness and innovativeness. In the stage performance Snutebiller, stankelben (Snout Beetle, Crane Fly) by the Norwegian theatre group Fleece & Rouge, four poems by Jacobsen are performed on stage with children as the target audience. This article studies the realization of Jacobsen’s poetry as stage art for children. Transferring the poems from book to stage involves several obvious medial transformations due to the theatre’s specific devices. By drawing theoretical inspiration from Jonathan Culler’s theory of the lyric poem’s ritualistic and fictional qualities, we ask to what degree the performance preserves the poetic qualities in the poems for the child audience. Or rather, does the theatre frame impose dramatic effects on the poems by expanding their element of fiction? The inquiry is also inspired by Margaret Meek’s and Kornej Tjukovskij’s perspectives on the relationship between children and poetic language. There is an amount of risk involved in the task of transferring poetry to the stage. In order to succeed, the actors must embrace the expressive possibilities of the theatre, which in one sense means replacing one genre with another and thus leaving the poetry behind. However, as the analysis of Snutebiller, stankelben demonstrates, the poetic may resurrect in the scenic expression, given that the performance’s embeddedness in and obligation towards the poems are strong enough.

Lipid Profiling in Cancer Diagnosis with Hand-Held Ambient Mass Spectrometry Probes: Addressing the Late-Stage Performance Concerns

Untargeted lipid fingerprinting with hand-held ambient mass spectrometry (MS) probes without chromatographic separation has shown promise in the rapid characterization of cancers. As human cancers present significant molecular heterogeneities, careful molecular modeling and data validation strategies are required to minimize late-stage performance variations of these models across a large population. This review utilizes parallels from the pitfalls of conventional protein biomarkers in reaching bedside utility and provides recommendations for robust modeling as well as validation strategies that could enable the next logical steps in large scale assessment of the utility of ambient MS profiling for cancer diagnosis. Six recommendations are provided that range from careful initial determination of clinical added value to moving beyond just statistical associations to validate lipid involvements in disease processes mechanistically. Further guidelines for careful selection of suitable samples to capture expected and unexpected intragroup variance are provided and discussed in the context of demographic heterogeneities in the lipidome, further influenced by lifestyle factors, diet, and potential intersect with cancer lipid pathways probed in ambient mass spectrometry profiling studies.

Effects of geometric and operational uncertainties on aerodynamic performance of centrifugal compressor stage

No real centrifugal compressor can exactly conform to its design geometry and expected operating conditions due to the uncertainties existing in the manufacturing and operational processes. Such uncertainties have been increasingly recognised to be detrimental to compressor performance. However, quite few studies have focused on the combined effects of geometric and operational uncertainties on compressor performance, and the underlying flow mechanism even remains unclear. In this context, we here present an uncertainty analysis of a centrifugal compressor stage, with both geometric and operational uncertainties taken into account. With the combination of CFD simulation and nonintrusive sparse grid based stochastic collocation methods, the combined and individual effects of total inlet temperature, total inlet pressure, outlet mass flow, impeller tip clearance and hub fillet radius on the stage/impeller performance are quantified and analysed. Particular attention is paid to elucidating the compressor performance variations through flow field and energy decomposition analyses. Results show that the considered uncertainties exert more influence on the compressor stage performance rather than on the impeller performance. Amongst the examined uncertainties, the impeller tip clearance contributes the most to the stage performance. The underlying mechanism lies in that the wake of impeller tip clearance produces distorted flow downstream towards the diffuser, which causes complicated vortex structures and less conversion of kinetic energy to pressure rise in the diffuser passage. The present study lays a theoretical foundation for the further uncertainty quantification and robust design of centrifugal compressors against various sources of uncertainties.

Dychotomy of the phenomenal and semiotic bodies of the performer in the context of a theater without an actor

modern theatrical art and to reveal the features of the phenomenal and semiotic body of the performer in theater performances without an actor. Research methodology. A synergetic method is applied, due to which the essence of the dichotomy of the phenomenal and semiotic body of the performer and the mechanism of its transformation in the process of transition from traditional theater to the theater without an actor is considered; a systemic method for analyzing the phenomenal and semiotic body of the performer as a manifestation of integrity in the unity of all connections and relationships; the method of comparative analysis, which contributed to the comparison of the ways of perception and understanding by the spectator of the semantic content of the stage performance in the traditional, puppet theater and theater without an actor, etc. Scientific novelty. The problems of theater without an actor are considered in the context of the theory of body dichotomy by B.S. Turner and the model of the alternation of the phenomenal and semiotic body of the performer in the post-dramatic theater E. Fischer-Lichte; the absence of actors as traditional components of the stage production of the play is theoretically substantiated; it was found that, despite the absence of performers, a theater without an actor is a unique phenomenon of modern theatrical art, realized due to the dichotomy of the phenomenal-semiotic nature of the actor's corporeality. Conclusions. The study revealed that the dichotomy of the phenomenal and semiotic body of an actor is a meaningful tool for studying the interpretation of various types of modern theater. Based on the analysis of theater performances without an actor ("Feng Shui in a theater without an actor" B. Bulatovic, A. Mustar and J. Šimenc, Slovenia, Ljubljana, Cultural Center "Španski borci", 2011, etc.) it was found that in the absence of the phenomenal body of the actor in the stage action, scenography and props become the material vehicle of the semiotic body. Destroying traditions and moving away from the "actor - spectator" attitude, depriving the viewer of an actor of a person, theatrical figures strive for contemplation, open new horizons for the theater, which can cause unusual sensations and feelings.

The locus of the house and images of the main characters in the play “Moscow” by Andrey Bely: towards a problem statement

The relevance of the article is based on the fact that over the past decades of the XXI century it has become the urgent need in philology to examine innovative methods, stylistic decisions, new narrative strategies used by the poet, writer, publicist, aesthete and philosopher Andrey Bely (1880–1934) in his last (Soviet) working period. The article considers the issue how in the 30s of the XX century Andrey Bely, being under the great influence of V. Meyerhold’s experimental theater, turned the first and second chapters of the novel “Moscow” (“The Moscow Eccentric” and “Moscow under Siege”) into the drama “Moscow” which wasn’t on the stage. A question is raised about Andrey Bely’s innovation as a playwright and some methods of the stage performance of the play “Moscow” are identified in the article. Special attention is paid to the locus of the house in the novel and drama, the question of transformation is raised: from the closed, protected, inner and personal space to the opened, hostile, unlocked one where hostile and mystic forces invade. The fight between two main antagonists — Korobkin, a scientist, and Mandro, a spy — is given in a wide mythological, christian and antroposophical context. The author of the article presents her many years experience on various approaches to understanding of not fully researched works (novel and play “Moscow”) by Andrey Bely.