scholarly journals Flow and Bed Topography in a River Confluence by Three-Dimensional Unsteady Flow Analysis

1995 ◽  
Vol 39 ◽  
pp. 435-440
Author(s):  
Shoji FUKUOKA ◽  
Munehiro IGARASHI ◽  
Tatsuya NISHIMURA ◽  
Setsuo MIYAZAKI
1997 ◽  
Author(s):  
C. Hah ◽  
F.-L. Tsung ◽  
J. Loellbach ◽  
C. Hah ◽  
F.-L. Tsung ◽  
...  

Author(s):  
Fabien Bardoux ◽  
Francis Leboeuf ◽  
Cédric Dano ◽  
Clément Toussaint

The first part of this paper analysed the time-averaged flow in a transonic single stage turbine. In this second part, we analyse the three-dimensional unsteady flow and temporal correlations in the rotor frame of reference. Two main conclusions are deduced from the comparison of each correlation. First, all correlations have the same order of magnitude. This is an important conclusion for models that handle the interaction between blade rows, because the temporal correlations are usually neglected. Second, these correlations occur in complementary localizations. In particular, the largest values of spatial deterministic correlations is located between the nozzle trailing edge and the rotor leading edge, as a consequence of nozzle wakes. Conversely, temporal deterministic correlations are located within the rotor blade row. We also establish that entropy accumulations in the stator wake near the end-wall regions generate high fluctuations of the rotor passage vortices. Such a phenomenon may have great repercussions on the radial loss distribution in the stage.


2000 ◽  
Author(s):  
B. V. Rathish Kumar ◽  
T. Yamaguchi ◽  
H. Liu ◽  
R. Himeno

Abstract Unsteady flow dynamics in a doubly constricted vessel is analyzed by using a time accurate Finite Volume solution of three dimensional incompressible Navier-Stokes equations. Computational experiments are carried out for various values of Reynolds number in order to assess the criticality of multiple mild constrictions in series and also to bring out the subtle 3D features like vortex formation. Studies reveal that pressure drop across a series of mild constrictions can get physiologically critical. Further this pressure drop is found to be sensitive to the spacing between the constrictions and also to the oscillatory nature of the inflow profile.


2019 ◽  
Vol 25 (5) ◽  
pp. 2145-2154 ◽  
Author(s):  
Johannes Novotny ◽  
Joshua Tveite ◽  
Morgan L. Turner ◽  
Stephen Gatesy ◽  
Fritz Drury ◽  
...  

1977 ◽  
Vol 43 (366) ◽  
pp. 596-604
Author(s):  
Takeshi ADACHI ◽  
Harutaka TSUJIMURA ◽  
Masamichi IMAIZUMI

Author(s):  
Man-Woong Heo ◽  
Tae-Wan Seo ◽  
Chung-Suk Lee ◽  
Kwang-Yong Kim

This paper presents a parametric study to investigate the aerodynamic and aeroacoustic characteristics of a side channel regenerative blower. Flow analysis in the side channel blower was carried out by solving three-dimensional steady and unsteady Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence closure. Aeroacoustic analysis was conducted by solving the variational formulation of Lighthill’s analogy on the basis of the aerodynamic sources extracted from the unsteady flow analysis. The height and width of the blade and the angle between inlet and outlet ports were selected as three geometric parameters, and their effects on the aerodynamic and aeroacoustic performances of the blower have been investigated. The results showed that the aerodynamic and aeroacoustic performances were enhanced by decreasing height and width of blade. It was found that angle between inlet and outlet ports significantly influences the aerodynamic and aeroacoustic performances of the blower due to the stripper leakage flow.


2018 ◽  
Vol 32 (9) ◽  
pp. 3219-3232 ◽  
Author(s):  
Nicola Lamaddalena ◽  
Roula Khadra ◽  
Bilal Derardja ◽  
Umberto Fratino

2011 ◽  
Vol 361-363 ◽  
pp. 603-606
Author(s):  
Yu Qiang Dai ◽  
Jiu Peng Zou ◽  
Che Zhu ◽  
Jin Tao Wu ◽  
Da Peng Hu

The unsteady flow behaviors in devices like gas wave machines, wave rotor refrigerators and so on are complex due to real gas effect at high operational pressure and low temperature. In this work, a detail computational model for unsteady flow analysis of real natural gases is established. The real effect on unsteady behaviors of natural gases in shock tubes have been studied extensively. Results show that the non-classical flow of the gases will not exist. The discipline of reflection and refraction of various gas waves or discontinuities remain unchanged for natural gases. Attention should be paid only to the deviations between perfect gas model and real gas model for gasdynamic waves.


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