Magnetization diffusion in duct flow: The magnetic entrance length and the interplay between hydrodynamic and magnetic timescales

2020 ◽  
Vol 32 (7) ◽  
pp. 072007
Author(s):  
Douglas Daniel de Carvalho ◽  
Rafael Gabler Gontijo
Keyword(s):  
Duct Flow ◽  
Entrance Length

Investigation of the Effect of Inlet Turbulence on Transitional Wall-Bounded Flows

2017 ◽  
Author(s):  
Burak Ahmet Tuna ◽  
Xianguo Li ◽  
Serhiy Yarusevych
Keyword(s):  
Boundary Layer ◽  
Turbulence Intensity ◽  
Initial Conditions ◽  
Hydraulic Diameter ◽  
Transition To Turbulence ◽  
Duct Flow ◽  
Entrance Length ◽  
Hot Wire ◽  
Boundary Layer Development ◽  
Layer Development

The present work investigates experimentally the effects of grid-generated turbulence on the transition and the hydrodynamic entrance length in a developing duct flow. Particle Image Velocimetry (PIV) and hot-wire anemometry are used to characterize the flow in a rectangular duct with a length of 1m (∼40Dh) and an aspect ratio of 2 (20mm × 40mm). The inlet turbulence intensity is controlled using different grids, and experiments are performed for a Reynolds number based on hydraulic diameter ReDh = 17,750. Hot-wire and PIV results show that the inlet turbulence intensity has a substantial effect on the flow evolution in the duct, as it substantially changes the boundary layer characteristics in the hydrodynamic entrance region. Analysis shows that, as expected, transition to turbulence advances upstream as the inlet turbulence intensity increases, leading to the decrease in the entrance length. The primary effect is confined to boundary layer development, as the turbulence intensity decays rapidly in the core flow, becoming independent of the initial conditions after about 10 hydraulic diameter (Dh) downstream from the grid. Thus, the analysis is focused on characterizing the boundary layer development and quantifying the associated changes in the flow development along the duct.

PREDICTION OF A TURBULENT REACTING DUCT FLOW WITH SIGNIFICANT RADIATION

1971 ◽  
Vol 32 (C5) ◽  
pp. C5b-27-C5b-31 ◽  
Author(s):  
F. C. Lockwood ◽  
D. B. Spalding
Keyword(s):  
Duct Flow

PIV MEASUREMENTS OF DUCT FLOW WITH A DETACHED TURBULATOR ARRAY

2001 ◽  
Vol 8 (2-3) ◽  
pp. 11
Author(s):  
Tong-Miin Liou ◽  
Shun-Nan Liou ◽  
K. H. Chang
Keyword(s):  
Duct Flow ◽  
Piv Measurements

Predicting S-duct flow using a composite algebraic stress model

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 327-335
Author(s):  
T. Jongen ◽  
G. Mompean ◽  
T. B. Gatski
Keyword(s):  
Stress Model ◽  
Duct Flow ◽  
Algebraic Stress Model

Thermal Performance Analysis of a Rectangular Longitudinal Finned Solar Air Heater With Semicircular Absorber Plate

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman
Keyword(s):  
Thermal Performance ◽  
Numerical Solutions ◽  
Solar Air Heater ◽  
Duct Flow ◽  
Balance Equations ◽  
Absorber Plate ◽  
Ansys Fluent ◽  
Air Heater ◽  
Glass Cover ◽  
Good Agreement

Thermal performance of a single-pass single-glass cover solar air heater consisting of semicircular absorber plate finned with rectangular longitudinal fins is investigated. The analysis is carried out for different hydraulic diameters, which were obtained by varying the diameter of the duct from 0.3–0.5 m. One to five numbers of fins are considered. Reynolds number ranges from 1600–4300. Analytical solutions for energy balance equations of different elements and duct flow of the solar air heater are presented; results are compared with finite-volume methodology based numerical solutions obtained from ansys fluent commercial software, and a fairly good agreement is achieved. Moreover, analysis is extended to check the effect of double-glass cover and the recycle of the exiting air. Results revealed that the use of double-glass cover and recycle operation improves the thermal performance of solar air heater.

Time varying control of magnetohydrodynamic duct flow

2021 ◽  
Author(s):  
Cansu Evcin ◽  
Ömür Uğur ◽  
Münevver Tezer-Sezgin
Keyword(s):  
Time Varying ◽  
Duct Flow
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