Computational Mechanics Research and Support for Aerodynamics ...
Computational Mechanics Research and Support for Aerodynamics ... Computational Mechanics Research and Support for Aerodynamics ...
Next, the air motion between the beams as the truck passes under the bridge is studied. Velocity vector plots with superimposed velocity isosurfaces are presented to understand the motion. A typical plot is shown in Figure 3.10 where the small arrows show the velocity at a specific instant of time. Because these vectors are difficult to see, a large red arrow is superimposed on the plots to show the general movement of the air in a given region. Figure 3.11 shows the middle cross section – i.e., the area perpendicular to the direction of truck motion -- through the air domain and velocity vectors together with the velocity isosurfaces. At 0.5 sec, the vehicle is approaching this cross section, and the air is starting to move up. At 1.0 sec, when the vehicle is passing under this cross section, the air on the top part of the domain behaves in a similar way. Increased velocities can be seen in the proximity of the vehicle wheels and around the trailer. At 1.5 sec, the vehicle is past this cross section, and the velocity vectors have changed directions. Now they are pointing downward, and as mentioned previously, the air is sucked down to the vacuum created behind the truck. With time, the vectors continuously change their directions. It is important to note that this mechanism could potentially cause transport of the air containing the water-salt spray from the road surface to the bridge beams. Figure 3.10: Close up view of the velocity vectors TRACC/TFHRC Y1Q3 Page 52
0.5 sec 1.0 sec 1.5 sec 2.0 sec 3.0 sec Figure 3.11: Velocity vectors in the middle cross section of the air domain TRACC/TFHRC Y1Q3 Page 53
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- Page 9 and 10: Figure 2.22: Velocity distribution
- Page 11 and 12: List of Tables Table 2.1: Boundary
- Page 13 and 14: experiments at TFHRC continued. A m
- Page 15 and 16: 2. Computational Fluid Dynamics for
- Page 17 and 18: ( ) ( ) (2.8) where A 0, A 1, and n
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- Page 29 and 30: Figure 2.13: Line probes created at
- Page 31 and 32: In Figure 2.15 the velocity and the
- Page 33 and 34: Mesh 1 Mesh 2 Mesh 3 Mesh 4 Mesh 5
- Page 35 and 36: Figure 2.20: Dimensional details of
- Page 37 and 38: Figure 2.22: Velocity distribution
- Page 39 and 40: Figure 2.25: CFD velocity contour p
- Page 41 and 42: Figure 2.27: CFD velocity contour p
- Page 43 and 44: Conclusions for Comparison with Exp
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- Page 67 and 68: Figure 3.17: FEM Model of a Ford F-
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Next, the air motion between the beams as the truck passes under the bridge is studied. Velocity vector<br />
plots with superimposed velocity isosurfaces are presented to underst<strong>and</strong> the motion. A typical plot is<br />
shown in Figure 3.10 where the small arrows show the velocity at a specific instant of time. Because<br />
these vectors are difficult to see, a large red arrow is superimposed on the plots to show the general<br />
movement of the air in a given region. Figure 3.11 shows the middle cross section – i.e., the area<br />
perpendicular to the direction of truck motion -- through the air domain <strong>and</strong> velocity vectors together<br />
with the velocity isosurfaces. At 0.5 sec, the vehicle is approaching this cross section, <strong>and</strong> the air is<br />
starting to move up. At 1.0 sec, when the vehicle is passing under this cross section, the air on the top<br />
part of the domain behaves in a similar way. Increased velocities can be seen in the proximity of the<br />
vehicle wheels <strong>and</strong> around the trailer. At 1.5 sec, the vehicle is past this cross section, <strong>and</strong> the velocity<br />
vectors have changed directions. Now they are pointing downward, <strong>and</strong> as mentioned previously, the air<br />
is sucked down to the vacuum created behind the truck. With time, the vectors continuously change<br />
their directions. It is important to note that this mechanism could potentially cause transport of the air<br />
containing the water-salt spray from the road surface to the bridge beams.<br />
Figure 3.10: Close up view of the velocity vectors<br />
TRACC/TFHRC Y1Q3 Page 52