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‘ig.9 Predicted 3D streamlines and velocity magnitude contours of wind at the heights of 1.75 and 30m around the La Salve Bridge in summer and winter times.

Figure 9 ‘ig.9 Predicted 3D streamlines and velocity magnitude contours of wind at the heights of 1.75 and 30m around the La Salve Bridge in summer and winter times.

Related Figures (11)

Table 1 Beaufort scale and wind speed conversions at a height of 10m with descriptions of effects on land [21,22].
Table 1 Beaufort scale and wind speed conversions at a height of 10m with descriptions of effects on land [21,22].
Table 2 Pedestrian comfort criteria based on NEN 8100 [25].
Table 2 Pedestrian comfort criteria based on NEN 8100 [25].
Fig. 1 Pictures and schematics in front, back and top views of the Guggenheim Museum [28].
Fig. 1 Pictures and schematics in front, back and top views of the Guggenheim Museum [28].
As shown in Fig. 3, the studied results of the wind conditions in terms of the direction, intensity and probability was based on the wind rose charts from a domestic meteorological station which indicated the wind blowing predominately over the Guggenheim Museum from the west in summertime and from the east in wintertime. The associated wind speeds oc- curred most frequently were 4.72m/s in summer and 6.43m/s in winter with the data acquired at 10m, to calculate the neutral ABL velocity, turbulent kinetic energy and turbulence dissipation rate profiles, as the incoming wind flow condition at the inlet of the com- putational domain [35,36]. In essence, roughness augments the drag for the wind over the land surface, causing that the logarithmic law for the velocity profile, being the basis of the standard wall function approach, is incorrect in the existence of roughness [37,38]. In the ANSYS Fluent® software, the effect of actual ob- stacles on the wind flow was modeled via the roughness wall function setup to simulate the obstacles applied to the bottom surface. From the updated Davenport roughness. classification [39], the aerodynamic
As shown in Fig. 3, the studied results of the wind conditions in terms of the direction, intensity and probability was based on the wind rose charts from a domestic meteorological station which indicated the wind blowing predominately over the Guggenheim Museum from the west in summertime and from the east in wintertime. The associated wind speeds oc- curred most frequently were 4.72m/s in summer and 6.43m/s in winter with the data acquired at 10m, to calculate the neutral ABL velocity, turbulent kinetic energy and turbulence dissipation rate profiles, as the incoming wind flow condition at the inlet of the com- putational domain [35,36]. In essence, roughness augments the drag for the wind over the land surface, causing that the logarithmic law for the velocity profile, being the basis of the standard wall function approach, is incorrect in the existence of roughness [37,38]. In the ANSYS Fluent® software, the effect of actual ob- stacles on the wind flow was modeled via the roughness wall function setup to simulate the obstacles applied to the bottom surface. From the updated Davenport roughness. classification [39], the aerodynamic
roughness was set to be 0.7m for the situation of rough terrain. In addition, the wall function roughness height (k,) was equivalent to around 30 times of the aerodynamic roughness (zo). To treat the boundary conditions, a constant static pressure boundary condi- tion was used at the outlet of the calculation domain. When the top and lateral boundaries were placed 10H and 6W away from the boundary layer (with H and W designated as the height of the target building and the width of built area, respectively), the symmetry bound- ary conditions were arranged by prescribing the zero normal component of velocity and zero normal deriva- ives for all flow variables at the boundaries. The governing equations were discredited by the finite con- rol volume approach. An iterative semi-implicit method for pressure-linked equations consistent (SIM- PLEC) numerical method was utilized for veloci- y-pressure coupling [40-42]. A steady-state solution was obtained with convergence of the normalized re- sidual errors of flow variables to 10° and the mass balance check under 0.5% for establishment of the wind field of outdoor environments. More detailed descrip- ion on the computational approach can be found in [43]. of core urban area with an enlarged view of numerica grids and (b) a schematic of boundary conditions. Complying with the best practice guidelines to layou he grids [44], the extent of the computational domain was appropriately selected to describe the relevant flow and geometrical details. More grid points were added o place on the original geometrical shape for local grid refinement in mimicking building features. In practice, his study circumvented the usage of tetrahedral ele- ments and non-orthogonal cells in boundary layers in addition to high aspect ratios away from boundaries. Highly skewed and highly warped cells were also cir- cumvented to maintain a suitable topology of the mesh shape in compliance with the requirements of skewness and aspect ratio (standing for the quality of a single cell as well as expansion ratio (denoting the ratio of the size of a cell to its neighboring cell). For good quality mesh, the aspect ratios should be avoided to be higher than 5:1 with the skewness under 0.85, up to 0.95 for acceptable conditions [32]. The expansion rate should be less than 10 to control change of cell volume with respect to neighboring cells. In this research, we mainly employed the body-fitted technique in the ICEM module to generate the unstructured prism mesh for boundary layer near the walls and the mixed meshs of tetrahedral and hexa for fitting to the building geometry and boundaries. The set values of the minimum or- thogonal quality, maximum aspect ratio and maximum cell skewness were 0.71, 4.43 and 0.83, suggesting the realization of a reasonably good quality mesh. ten pantera) AAR Sere melee Pena ok
roughness was set to be 0.7m for the situation of rough terrain. In addition, the wall function roughness height (k,) was equivalent to around 30 times of the aerodynamic roughness (zo). To treat the boundary conditions, a constant static pressure boundary condi- tion was used at the outlet of the calculation domain. When the top and lateral boundaries were placed 10H and 6W away from the boundary layer (with H and W designated as the height of the target building and the width of built area, respectively), the symmetry bound- ary conditions were arranged by prescribing the zero normal component of velocity and zero normal deriva- ives for all flow variables at the boundaries. The governing equations were discredited by the finite con- rol volume approach. An iterative semi-implicit method for pressure-linked equations consistent (SIM- PLEC) numerical method was utilized for veloci- y-pressure coupling [40-42]. A steady-state solution was obtained with convergence of the normalized re- sidual errors of flow variables to 10° and the mass balance check under 0.5% for establishment of the wind field of outdoor environments. More detailed descrip- ion on the computational approach can be found in [43]. of core urban area with an enlarged view of numerica grids and (b) a schematic of boundary conditions. Complying with the best practice guidelines to layou he grids [44], the extent of the computational domain was appropriately selected to describe the relevant flow and geometrical details. More grid points were added o place on the original geometrical shape for local grid refinement in mimicking building features. In practice, his study circumvented the usage of tetrahedral ele- ments and non-orthogonal cells in boundary layers in addition to high aspect ratios away from boundaries. Highly skewed and highly warped cells were also cir- cumvented to maintain a suitable topology of the mesh shape in compliance with the requirements of skewness and aspect ratio (standing for the quality of a single cell as well as expansion ratio (denoting the ratio of the size of a cell to its neighboring cell). For good quality mesh, the aspect ratios should be avoided to be higher than 5:1 with the skewness under 0.85, up to 0.95 for acceptable conditions [32]. The expansion rate should be less than 10 to control change of cell volume with respect to neighboring cells. In this research, we mainly employed the body-fitted technique in the ICEM module to generate the unstructured prism mesh for boundary layer near the walls and the mixed meshs of tetrahedral and hexa for fitting to the building geometry and boundaries. The set values of the minimum or- thogonal quality, maximum aspect ratio and maximum cell skewness were 0.71, 4.43 and 0.83, suggesting the realization of a reasonably good quality mesh. ten pantera) AAR Sere melee Pena ok
Fig. 8 Predicted 3D streamlines and velocity magnitude contours of wind at the height of 12m around the entrance in summer and winter times.
Fig. 8 Predicted 3D streamlines and velocity magnitude contours of wind at the height of 12m around the entrance in summer and winter times.
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