230 Wind Tunnel Experiments of Exhaust Gas Dispersed in a Street Canyon : Comparison between Large-Scale Turbulence and Grid Turbulence

2014 ◽  
Vol 2014.63 (0) ◽  
pp. _230-1_-_230-2_
Author(s):  
Nobumasa SEKISHITA ◽  
Yasuhiro MASUDA
Keyword(s):  
Wind Tunnel ◽  
Street Canyon ◽  
Large Scale ◽  
Grid Turbulence ◽  
Exhaust Gas ◽  
Wind Tunnel Experiments ◽  
Scale Turbulence

Wind Tunnel Experiments of Large Scale turbulence generated on Roughness Surface

2002 ◽  
Vol 2002.3 (0) ◽  
pp. 69-70
Author(s):  
Nobumasa SEKISHITA ◽  
Hideharu MAKITA ◽  
Shirohisa KOBAYASHI
Keyword(s):  
Wind Tunnel ◽  
Large Scale ◽  
Wind Tunnel Experiments ◽  
Roughness Surface ◽  
Scale Turbulence

The Influence of Large-Scale High-Intensity Turbulence on Vane Heat Transfer

1997 ◽  
Vol 119 (1) ◽  
pp. 23-30 ◽  
Author(s):  
F. E. Ames
Keyword(s):  
Heat Transfer ◽  
High Intensity ◽  
Large Scale ◽  
Reynolds Numbers ◽  
Surface Heat ◽  
Grid Turbulence ◽  
Stagnation Region ◽  
Linear Cascade ◽  
Pressure Surface ◽  
Scale Turbulence

An experimental research program was undertaken to examine the influence of large-scale high-intensity turbulence on vane heat transfer. The experiment was conducted in a four-vane linear cascade at exit Reynolds numbers of 500,000 and 800,000 based on chord length. Heat transfer measurements were made for four inlet turbulence conditions including a low turbulence case (Tu ≅ 1 percent), a grid turbulence case (Tu ≅ 7.5 percent), and two levels of large-scale turbulence generated with a mock combustor at two upstream locations (Tu ≅ 12 percent and 8 percent). The heat transfer data demonstrated that the length scale, Lu, has a significant effect on stagnation region and pressure surface heat transfer.

Evolution of the turbulence structure in the surf and swash zones

2010 ◽  
Vol 644 ◽  
pp. 193-216 ◽  
Author(s):  
IN MEI SOU ◽  
EDWIN A. COWEN ◽  
PHILIP L.-F. LIU
Keyword(s):  
Large Scale ◽  
Surf Zone ◽  
Early Stage ◽  
Vertical Plane ◽  
Turbulence Energy ◽  
Breaking Wave ◽  
Turbulence Structure ◽  
Grid Turbulence ◽  
Mean Flow ◽  
Scale Turbulence

The velocity field and turbulence structure within the surf and swash zones forced by a laboratory-generated plunging breaking wave were investigated using a particle image velocimetry measurement technique. Two-dimensional velocity fields in the vertical plane from 200 consecutive monochromatic waves were measured at four cross-shore locations, shoreward of the breaker line. The phase-averaged mean flow fields indicate that a shear layer occurs when the uprush of the bore front interacts with the downwash flow. The turbulence characteristics were examined via spectral analysis. The larger-scale turbulence structure is closely associated with the breaking-wave- and the bore-generated turbulence in the surf zone; then, the large-scale turbulence energy cascades to smaller scales, as the turbulent kinetic energy (TKE) evolves from the outer surf zone to the swash zone. Smaller-scale energy injection during the latter stage of the downwash phase is associated with the bed-generated turbulence, yielding a −1 slope in the upper inertial range in the spatial spectra. Depth-integrated TKE budget components indicate that a local TKE equilibrium exists during the bore-front phases and the latter stage of the downwash phases in the outer surf zone. The TKE decay resembles the decay of grid turbulence during the latter stage of the uprush and the early stage of the downwash, as the production rate is small because of the absence of strong mean shear during this stage of the wave cycle as well as the relatively short time available for the growth of the bed boundary layer.

Sign in / Sign up

Export Citation Format

Share Document