Research on Wind Pressure Distribution of Plastic Greenhouses in Valley Topography

Abstract

As the wind pressure distribution on plastic greenhouses in valley areas is different from that of greenhouses on plains, it is necessary to find out the variation trend of the wind pressure coefficient on greenhouses in the valley areas. Based on the 'Realizable k- turbulence' model, the wind pressure characteristics on plastic greenhouses located in valley and plain areas are studied by using the verified numerical simulation method. The wind pressures on greenhouses and the corresponding fitting formula are obtained for different distances between the greenhouse and the foot of the mountain with a 0-degree wind angle. The results show that, with an increase of distance to the mountain, the positive wind pressure on the windward side of a plastic greenhouse increases and the negative wind pressure on the leeward side, roof surface and crosswind sides of the greenhouse decreases. The results from the proposed formulae are very close to those derived from the numerical simulation method, and the relative errors are all within 10%. The influence of canyon wind on the wind pressure distribution on plastic greenhouses should be considered in the design. This research can provide a reference for the wind resistance design of plastic greenhouses built in valley areas.

Analysis of Wind Pressure Coefficients for Single-Span Arched Plastic Greenhouses Located in a Valley Region Using CFD

“…Thus, greenhouse azimuths of 45 • and 90 • were selected in this study. Research on an azimuth of 0 • has been presented by Xu et al [10].…”

“…As the turbulence intensity is not clearly defined in Chinese codes, the turbulence kinetic energy k and turbulence dissipation rate ε are gained from a Japanese specification [46]. The formulas for exponential wind speed V, turbulence kinetic energy k, and turbulence dissipation rate ε are from Xu et al [10].…”

“…Wind load is closely related to the wind pressure coefficient C p [8,9], whose formula was presented in Xu et al [10]. There are currently three main methods to determine wind pressure coefficients, i.e., field experiment, wind tunnel test, and computational fluid dynamics (CFD).…”

“…Wind pressure values with various spans of Venlo-type greenhouses have also been analyzed based on turbulence models [28]. To affirm the accuracy and precision of the numerical simulation model, many study results on CFD model evaluation [8,10,29] have been compared with the results of the field experiments of Wells and Hoxey [30] and Hoxey and Richardson [31,32] or wind tunnel measurements of Robertson et al [33]. It is not difficult to see that scholars have been very skilled in using CFD to study wind pressure, but there are still many problems in some aspects.…”

The Influence of Mountain Height and Distance on Shape Factor of Wind Load of Plastic Tunnel

“…Wind load is one of the main loads to be controlled when designing engineering structures; many scholars have studied the characteristics of wind load under different working conditions [4][5][6][7][8][9][10][11][12], including studies on the influence of mountain topography, height and distance on wind load [13][14][15][16][17][18]. The shape factor of wind load is an indispensable parameter when calculating wind load, and it can be obtained by three methods: field tests [19][20][21][22], wind tunnel tests [23][24][25][26] and numerical simulations [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Wang et al [19], Yang et al [20] and Kwon et al [22] obtained the wind pressure pattern using the wind tunnel test, while Li et al [23] and Hoxey et al [26] gained full-scale results for the wind pressure characteristic.…”