112,141 research outputs found
TRANSONIC AFTERBODY SIMULATION
No full textOne challenge of numerical investigations of unsteady super- and hypersonic flow fields is the study of turbulent wake flow and the interaction with nozzle sections at modern launcher configurations. Unsteady side-loads, induced by the interaction of flow separation inside of the nozzle and the launcher wake will strongly influence the design of future main stage propulsion systems. This interaction phenomenon, called buffeting coupling, is one of the main challenges during ascent. The purpose of the presented study is to simulate a combined generic base-flow nozzle configuration under fully turbulent conditions. It is intended as a generic model of the central stage of a launcher, including central body and nozzle area. Experimental data under transonic conditions is available from wind tunnel tests in the scope of the ATAC program. Simulations are carried out with recent turbulence models like detached-eddy simulation (DES). DES is a hybrid technique proposed by Spalart et.al. for the simulation of this kind of turbulent unsteady flows. The idea is to combine the best features of Reynolds-averaged Navier-Stokes (RANS) and the large eddy simulation (LES) for the computation of realistic configurations at high Reynolds numbers.
The study was carried out by means of unstructured grids in the whole area including jet- and nozzle flow. Special care was taken on the influence of the time step size on the unsteady results and on grid influences. Comparisons with experimental pressure data, RMS distributions and power spectra have shown good agreement with the predicted DES results
Interpreting motives and barriers of cinema attendance: a behavioural and contextual approach
No full textNo abstract availabl
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
UNSTEADY INVESTIGATION OF THE DLR TIC NOZZLE BY DIFFERENT TURBULENCE MODELS
No full textAfterbodys of launchers and re-entry vehicles are characterized by large base regions submitted to intense back flow, aerodynamic instabilities and pressure fluctuations on the afterbody and on the nozzle region. Consequently in addition to experimental investigations a necessary capability of numerical tools is the capability to simulate unsteady super- and hypersonic flow fields of such configuration and to resolve turbulent wake flows, interacting with nozzle sections, on realistic launcher configurations.
One of the experimental activities in this scope was performed by DLR at the P6.2 facility in Lampoldshausen, Germany, providing an experimental data base for the DLR TIC nozzle under overexpanded cold gas conditions. Key objectives of this test case are the correct prediction of the separation location and the assessment of the resulting unsteady side load torque. The geometry was specified by DLR, including nozzle inner and outer wall and the inflow geometry upstream the nozzle throat.
The present computations were performed as a feasibility study, end preliminary results are presented here.Different computations on unstructured grids were carried out with grid adaptation at the shock structures. The test case was investigated by different descriptions of the turbulent flow field such as one equation URANS models and a DES (Detached Eddy Simulation) type simulation as well as laminar conditions. It has to be pointed out that the investigated grids are too coarse for a realistic DES and the resulting turbulence is only insufficiently resolved. Nevertheless the behaviour of the model under these conditions had to be investigated to earn experience for further simulations
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Авторскре свидетельство 1613795 SU
No full textSeveryanin, Vitaly Stepanovich; Veruleishvili, Filimon Avtandilovich; Katsevich, V. K. Steam generato
Авторское свидетельство 1490384 SU
No full textSeveryanin, Vitaly Stepanovich; Katsevich, V. K.; Veruleishvili, Filimon Avtandilovich. Pulsating combustion devic
Авторское свидетельство 1314195 SU
No full textBerezin, S. E.; Vasin, N. V.; Severyanin, Vitaly Stepanovich; Dmukhaylo, Evgeny Ivanovich; Katsevich, V. K.; Veruleishvili, Filimon Avtandilovich. Installation for thermal treatment of liquid wast
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