Closure to “Discussion of ‘A Length-Scale Model for Developing Turbulent Flow in a Rectangular Duct’” (1977, ASME J. Fluids Eng., 99, p. 784)

1977 ◽  
Vol 99 (4) ◽  
pp. 784-784 ◽  
Author(s):  
F. B. Gessner ◽  
A. F. Emery
1999 ◽  
Vol 125 (7) ◽  
pp. 780-788 ◽  
Author(s):  
Wihel Altai ◽  
Jian-bo Zhang ◽  
Vincent H. Chu

1977 ◽  
Vol 99 (2) ◽  
pp. 347-356 ◽  
Author(s):  
F. B. Gessner ◽  
A. F. Emery

A three-dimensional mixing length model is proposed for modeling local Reynolds stress behavior in rectangular ducts of arbitrary aspect ratio. The model is applicable to both developing and fully-developed flows, and can be applied to other 90-degree corner flows with mild streamwise pressure gradients. Comparisons between theory and experiment show that all components of the Reynolds stress tensor are modeled reasonably well, both in the vicinity of a corner and in two-dimensional regions away from the corner.


1981 ◽  
Vol 103 (3) ◽  
pp. 445-453 ◽  
Author(s):  
F. B. Gessner ◽  
A. F. Emery

Comparisons are made between experimental data and numerical predictions based on a three-dimensional length-scale model applicable to developing turbulent flow in rectangular ducts of arbitrary aspect ratio. The numerical method utilizes an explicit (Dufort-Frankel) differencing scheme for the axial momentum equation and involves no iterative procedures. Although the basic technique has been applied previously to another class of three-dimensional flows, it has not been applied until now to slender shear flows dominated by secondary flow of the second kind. The merits of the length-scale model and the computational procedure are assessed by means of comparisons with results referred to both k–ε and full Reynolds stress closure models which have been applied in recent years.


Ultrasonics ◽  
2021 ◽  
Vol 114 ◽  
pp. 106366
Author(s):  
Korpong Viriyananon ◽  
Jirachai Mingbunjerdsuk ◽  
Teerapat Thungthong ◽  
Weerachai Chaiworapuek

Author(s):  
N Kharoua ◽  
L Khezzar

Large eddy simulation of turbulent flow around smooth and rough hemispherical domes was conducted. The roughness of the rough dome was generated by a special approach using quadrilateral solid blocks placed alternately on the dome surface. It was shown that this approach is capable of generating the roughness effect with a relative success. The subgrid-scale model based on the transport of the subgrid turbulent kinetic energy was used to account for the small scales effect not resolved by large eddy simulation. The turbulent flow was simulated at a subcritical Reynolds number based on the approach free stream velocity, air properties, and dome diameter of 1.4 × 105. Profiles of mean pressure coefficient, mean velocity, and its root mean square were predicted with good accuracy. The comparison between the two domes showed different flow behavior around them. A flattened horseshoe vortex was observed to develop around the rough dome at larger distance compared with the smooth dome. The separation phenomenon occurs before the apex of the rough dome while for the smooth dome it is shifted forward. The turbulence-affected region in the wake was larger for the rough dome.


2021 ◽  
Vol 2116 (1) ◽  
pp. 012036
Author(s):  
A Blishchik ◽  
S Kenjereš

Abstract The current study is focused on the magnetohydrodynamics and demonstrates how electrical conductivity of the wall can affect the turbulent flow in the square duct. Different variations of the boundary walls have been considered including arbitrary conductive walls. The Large Eddy Simulations method with the dynamic Smagorinsky sub-grid scale model have been used for the turbulent structures resolving. Results show the significant impact of the wall conductance parameters for both Hartmann and side walls.


1988 ◽  
Vol 54 (504) ◽  
pp. 2002-2009
Author(s):  
Hideomi FUJITA ◽  
Masafumi HlROTA ◽  
Hajime YOKOSAWA ◽  
Masao HASEGAWA

2003 ◽  
Vol 125 (2) ◽  
pp. 228-232 ◽  
Author(s):  
F. L. Eisinger ◽  
R. E. Sullivan ◽  
P. Feenstra ◽  
D. S. Weaver

Acoustic vibration in two stack liners located inside a stack downstream of two induced draft fans occurred at high loads. Measurements confirmed that an acoustic wave developed in the fundamental diametral mode of the cylindrical stack liners. It manifested itself as a pure tone traveling through the stack to surrounding residential areas. It was suspected that turbulent flow in the pipe bends upstream of the stack and downstream of the fans was the source of the excitation. Laboratory scale model tests confirmed that the bends indeed acted as the source. Two guide vane configurations placed inside the bends were tested experimentally. The tests showed that properly placed guide vanes would reduce the acoustic levels in the stack. The paper gives a description and evaluation of the problem.


Sign in / Sign up

Export Citation Format

Share Document