Numerical simulation in the wind action analyses in logistic sheds with a

bridge vent

LUAN A. MENDES, MARCO D. DE CAMPOS

Institute of Exact and Earth Sciences

Federal University of Mato Grosso,

zones in the flow visualization.

Key-Words: Wind action, Ansys, logistic shed, bridge vent, pressure coefficients.

Received: April 12, 2022. Revised: March 9, 2023. Accepted: April 5, 2023. Published: April 25, 2023.

The ridge vent is a metal structure installed on the

ridge of the roof widely used in various buildings

halls, and greenhouses [1]. Usually is employed for

The Venturi effect is the result of the combination of

a small inlet with a large outlet, producing a

concentrated air movement and higher speed,

limited to a small section of the environment [3].

building as safety openings [4]. In general, only its

load, depending on the proportion, the type of

lantern, and, likewise, the wind incidence [5]. In the

literature, ridge vent use is an element to favor

natural ventilation [1] or specific cases, such as

roof with the presence of ridge vents are necessary

[5].

2 Methodology

In this work were done meshes and post-processing

with the Ansys Workbench software. For geometry

modeling, Autodesk AutoCAD software.

According to [9] was used a control volume

composed of the structure to be analyzed,

dimensions depend on the height H of the building,

with a distance of 5H and 15H between the entrance

and the exit and the building, respectively; and 6H

neighborhood conditions, namely the number and

in conjunction with the different angles of wind

incidence, the geometrical characteristics of the

industrial shed are summarized in Fig. 1 (c-f). To

The Ansys Fluid Flow software, and the Shear

Stress Transport turbulence model, were adopted

condition and non-dimensional parameter details.

Fig. 1 (a) Control volume and (b-f) geometry and

different angles of incidence of the wind.

3 Numerical applications

Application 1 (Validation): Here, for two wind

buildings with gable roofs were calculated and

the external pressure coefficients in the structure,

and Table 2 presents the values obtained for the

for a critical t=1.78. As 0.50<1.78, it was possible to

values of Cpe is insignificant. Likewise, for wind at

90°, p-value=0.45 was obtained for a critical t=1.78.

intensity than those in the isolated structure without

surrounding buildings. In both cases, the more

the wind, reducing the pressure coefficients of the

more leeward building (Fig. 5). However, for the

vortices occurred in the leeward of the building,

boosting the small suction zones in this region (Fig.

To clarify the shielding effect on leeward buildings,

notice a reduction of the negative Cpe (Fig. 6).

However, in the logistic shed without a ridge vent,

the negative values of Cpe were more intense, and

in the main roof, a larger suction region was noted

Between the logistic shed with a ridge vent formed

conical vortices and suction tips. In addition, this

ridge vent compared to the logistic shed without a

ridge vent. Consequently, the logistic shed with a

ridge vent endangered the neighboring buildings,

case, occurred on the most windward building.

Wind at 90°

Fig. 6 Top view for the Cpe contour for side-by-side logistics shed (a) with and (b) without ridge vents.

Also, the decrease in wind speed in the logistics

are relevant to wind damage to the roofing system

some 50% of the lift force to delta-wing aircraft.

the windward side, the lines of air current formed

dynamic effects generating a region of turbulence in

extension of the ridge vent. However, the suction

shed without a ridge vent (Fig. 9). The closed ridge

Case 4 (wind at 135°): In this case, the geometric

configuration (Fig. 8) favored that the flow, when

along the contour. It was also possible to notice the

shielding effect caused by the logistic shed further

there was a funneling of the flow.

with the flow funneling. Building area density,

relative height, and arrangement patterns of

surrounding buildings are relevant factors in

shielding. When the density of the building area

wind pressure coefficients gradually decrease. In

this way, the density of buildings is favorable in

shielded a portion of the runoff. As a result, there

Wind at 45°

Wind at 90°

Fig. 8 Top view for the Cpe contour for three side-by-side logistic sheds (a) with and (b) without a ridge vents.

For validation methodology, according to [10], it

two wind directions (0° and 90°). The T-test was

used to determine significant differences between

Cpe of the present work results and [10] showed the

and without a ridge wind were similar to the wind

blowing at 0° on the smaller facade. In this

a ridge vent, there was an increase in suction.

Finally, with the wind at 90°, in the logistic shed

45°, the corners of the building formed top vortices,

and for the sheds further back, the neighborhood

In the side-by-side logistic shed with a closed ridge

vent, there was a significant influence on the

distribution of average pressures on the roof cover,