CN101936057A - Pneumatic wind guide device for Fujian earth buildings - Google Patents

Abstract

The invention discloses a pneumatic wind guide device for Fujian earth buildings, which is a wind guide annular plate erected around ridges of the Fujian earth buildings. By adopting the proposal, the wind guide annular plate is erected around the ridges of the Fujian earth buildings using a structural pneumatic technology to change the air flow status of high-speed air flow around an overhang of a roof during the typhoon period, which effectively lowers wind load applied to a roof surface so as to achieve the purposes of preventing and reducing wind-induced damage to the roof. The operating principle of the pneumatic wind guide device can be explained by an idea of 'Emperor Yu tames the flood': Emperor Yu takes 'drainage' instead of 'water shutoff' measures in a water control scheme to effective reduce flood disasters, so the device of the invention is called as 'wind guide' rather than 'wind resistance'. By adopting the wind guide device of the invention, rigidity and strength of the roof and support components thereof do not need to be strengthened, the normal use condition of the earth buildings is not affected, and appearance style of the earth buildings is not changed, thus having good protection significance and application value.

Description

The pneumatic air ducting of Fujian Tulou

Technical field

The present invention relates to the protection and the Structural Wind Engineering field of World Heritage Site, specifically is the pneumatic air ducting at the Fujian Tulou.

Background technology

" Fujian Tulou " got permission to list in " World Heritage List " in 2008, and be most important to its protection work.The Fujian Tulou is distributed in the southeastern coastal areas, and the example that destroyed by typhoon is of common occurrence.To go out eaves bigger because of its roof system, supported by timber frame below, and to the wind load sensitivity, roof system often is damaged in typhoon attacks.

In the prior art, a lot of at the wind resistance measure of building, but generally to be strength and stiffness by reinforcement meet the demands for they, and this can influence the genuine whole style and features of Tulou world heritage, does not meet the protection demand of legacy.

Summary of the invention

The purpose of this invention is to provide the pneumatic air ducting of a kind of Fujian Tulou, it can solve the problem that Fujian Tulou roof system charming appearance and behaviour is damaged on the basis of the former wind original appearance that does not change Tulou.

To achieve these goals, the present invention adopts following technical scheme:

Tulou pneumatic air ducting in Fujian is for centering on the wind-guiding ring flat-plate that is erected in Tulou ridge place, Fujian.

The material of above-mentioned wind-guiding ring flat-plate adopts native brick and tile, can be consistent with Tulou primitive architecture material.

The height of above-mentioned wind-guiding ring flat-plate is 0.01-0.05 with the ratio of the height of Fujian Tulou ridge.

After adopting such scheme, the present invention adopts the structure pneumatics, at Tulou ridge place, Fujian annular is set and erects the wind-guiding ring flat-plate, can change high velocity air during the typhoon around the cornice air flow condition at place of roof system, reduce acting on the wind load on roof system surface effectively, thereby reach the charming appearance and behaviour destruction that prevents and reduce roof system.Its operating principle is that the theory that available Da Yu harnesses the river illustrates: Da Yu can alleviate flood effectively, its scheme of harnessing the river is to adopt " hydrophobic ", rather than adopt " water blockoff " measure to realize, so apparatus of the present invention are called " wind-guiding ", but not " wind resistance ".Adopt air ducting of the present invention, need not strengthen the rigidity and the intensity of roof system and supporting member thereof, do not influence the normal operating condition of Tulou, do not change the outward appearance style and features of Tulou, have good protection meaning and using value.

Air ducting simple structure of the present invention; need only increase ridge protuberance little height, particularly available brick and tile material (also available certainly other material) keeps Tulou original of an antique style; do not damage the genuine whole style and features of Tulou world heritage, meet the protection demand of legacy.

Air ducting wide adaptability of the present invention is not only applicable to annular Tulou building (comprising circular and square), for other than ring type Tulou building (as semicircle, ∏ font), pneumatic preferably unloading effect is arranged also.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the invention one;

Fig. 2 is the Tulou zoning plan in the embodiment of the invention one;

Fig. 3 is the vertical cut-away view in the embodiment of the invention one;

Fig. 4 is the clean wind stress factor schematic diagram at the outer place of cornicing of the embodiment of the invention one;

Fig. 5 is the clean wind stress factor schematic diagram at the place of cornicing in the embodiment of the invention one;

Fig. 6 is the structural representation of the embodiment of the invention two;

Fig. 7 is the Tulou zoning plan in the embodiment of the invention two;

Fig. 8 cornices at the clean wind stress factor schematic diagram in 0 ° of wind angle following time for the embodiment of the invention two outer;

Fig. 9 cornices at the clean wind stress factor schematic diagram in 30 ° of wind angle following times for the embodiment of the invention two outer;

Figure 10 cornices at the clean wind stress factor schematic diagram in 45 ° of wind angle following times for the embodiment of the invention two outer;

Figure 11 cornices at the clean wind stress factor schematic diagram in 60 ° of wind angle following times for the embodiment of the invention two outer;

Figure 12 is provided with preceding section wind vector figure for wind-guiding ring flat-plate in the embodiment of the invention one;

Figure 13 is the section wind vector figure after the wind-guiding ring flat-plate is provided with in the embodiment of the invention one;

The specific embodiment

Now with of the case study on implementation explanation of most typical annular with the annular Tulou in side

Embodiment one:

The pneumatic air ducting of Fujian of the present invention Tulou, embodiment one is an example with circular Tulou, as shown in Figure 1, this pneumatic air ducting is for centering on the wind-guiding ring flat-plate 1 that is erected in circular Tulou 3 ridge places.The subregion of circular Tulou is divided as shown in Figure 2, and Fig. 3 is the vertical cut-away view of circular Tulou.The height of supposing wind-guiding ring flat-plate 1 is h, and the ridge height of circular Tulou 3 is H.For the height h that reflects wind-guiding ring flat-plate 1 influence to the roof system blast, analyze its aerodynamic effect by the different h values in the table 1, the modeling of circular Tulou is according to real size, get the ridge height H=11m of circular Tulou, getting the interior exterior wall spacing of circular Tulou is d, d=5m, radius R=0.55H.

Table 1

Adopt the method for numerical simulation of computational fluid dynamics (Computational Fluid Dynamics), calculate wind angle and ring flat-plate height change, analyze the unloading effect of aerodynamic Measures with this to the regularity of distribution of roof system wind load.

In aerodynamics, wind stress factor is the dimensionless number that corresponds to certain reference point, can be expressed as:

$C_{\mathrm{pi}}=\frac{p_i}{\frac{1}{2}\mathrm{\ρ}{\stackrel{\‾}{u}}^2}$

In the formula: C _PiIt is the wind stress factor of building surface measuring point i; p _iIt is the clean wind pressure of measuring point i;

It is the wind speed of reference point.

The average wind stress factor of the roof system of this paper is defined as C _p, be wind stress factor C with each calculation level _Pi, to do to obtain after the weighted average by area A i under this point, its calculating formula is

$C_p=\frac{\mathrm{\Σ}{C}_{\mathrm{Pi}}{A}_i}{\mathrm{\Σ}{A}_i}$

In the actual engineering, generally the clean wind stress factor on the employing face is also referred to as clean wind carrier model coefficient.

This paper is by with roof system upper and lower surface subregion, the difference of the average blast of upper and lower surface can be characterized the clean wind stress factor Δ Cp of roof system, as shown in the formula:

Δ Cp=Cp ' _On-Cp _Down

H is the height of wind-guiding ring flat-plate 1 in table 1 and the table 2, and H is the ridge height of circular Tulou, and h/H=0 does not promptly establish the situation of wind-guiding ring flat-plate, and e is the off-load rate of average clean wind stress factor:

$e=\frac{|\mathrm{\ΔC}{p}_{0j}-\mathrm{\ΔC}{p}_{\mathrm{ij}}|}{\left|\mathrm{\ΔC}{p}_{0j}\right|}\×100\%$

Δ Cp wherein _0j: the clean wind stress factor of j wind angle when not having the wind-guiding ring flat-plate (on behalf of wind angle, j change).Δ Cp _IjThe clean wind stress factor (i represents the variation of measuring point) of corresponding j wind angle i measuring point.

Shown in Fig. 4,5, circular Tulou 3 outer cornices bigger than the clean wind stress factor at the interior place of cornicing, in the cornice whole clean wind stress factor at place very little, the clean wind stress factor maximum in W1 district and W8 district is the least favorable position under the down wind effect.When the height that the wind-guiding ring flat-plate is set was 0.05H, the clean wind stress factor in W1 district became-0.65 by-1.5, and decompression can reach more than 50, and effect is obvious, shown in the concrete off-load counting rate meter 2.

Table 2

Embodiment two:

Embodiment two is an example with square Tulou, as shown in Figure 6, this pneumatic air ducting is for centering on the wind-guiding ring flat-plate 2 that is erected in square Tulou 4 ridge places, and the subregion of square Tulou is divided as shown in Figure 7, the height of supposing wind-guiding ring flat-plate 2 is h, and the ridge height of square Tulou 4 is H.For the height h that reflects wind-guiding ring flat-plate 2 influence to the roof system blast, also come analog computation by the h value in the table 1, the modeling of square Tulou is according to real size, get the ridge height H=11m of square Tulou, getting the interior exterior wall spacing of square Tulou is d, d=5m, length of side 2R=1.4H.

Adopt the analysis in like manner of the method for numerical simulation of computational fluid dynamics (Computational Fluid Dynamics), shown in Fig. 8-11, outer the cornicing in wind-guiding ring flat-plate 2 backs is set as can be seen effect of easing stress is all arranged under each wind angle, see that from integral body the least favorable position is 0 ° of W1 district and W8 district under the wind angle, the clean wind stress factor of this moment is approximately-1.82, when being set, the wind-guiding ring flat-plate of h=0.05H height becomes-1.1, off-load rate 45, specifically the decompression rate of unfavorable position is as shown in table 3 under each wind angle.

Table 3

The wind-guiding ring flat-plate of Tulou setting can reduce roof system wind load value, and its pneumatic off-load mechanism can illustrate with the aerodynamic flow field characteristic.The ridge that Figure 12-13 is respectively circular Tulou is provided with wind-guiding ring flat-plate front and back wind field comparison diagram, and by wind field contrast among Figure 12-13 as can be known: the wind-guiding ring flat-plate of setting has alleviated the bump of air-flow to upper surface, thereby plays the effect of off-load wind load.The cornice incoming flow of leading edge of wind-guiding ring flat-plate backhouse lid is set separates and weaken gradually, and leeward cornice to form significantly reflux, offset the high negative pressure of ridge with the incoming flow bump that facings the wind, the turbulence intensity of house cap integral reduces; The inner column strength of vortex of circular Tulou weakens gradually, and the vortex of leeward side diminishes, and the wake flow development is more abundant.

Claims (3)

1. Tulou pneumatic air ducting in Fujian is characterized in that: for centering on the wind-guiding ring flat-plate that is erected in Tulou ridge place, Fujian.

2. the pneumatic air ducting of Fujian according to claim 1 Tulou, it is characterized in that: the material of above-mentioned wind-guiding ring flat-plate adopts native brick and tile, can be consistent with Tulou primitive architecture material.

3. Tulou pneumatic air ducting in Fujian according to claim 1 is characterized in that: the height of above-mentioned wind-guiding ring flat-plate is 0.01-0.05 with the ratio of the height of Fujian Tulou ridge.

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