尖顶型温室风压数值模拟与研究

On Wind Pressure on Greenhouses with a Pointed Roof with Numerical Simulation

设施农业是高度现代化与集约化的新型农业生产方式,作为设施农业中最高效、应用最广的温室,其结构安全及室内指标测量与控制是当前的研究方向.风荷载是引起温室结构破坏的主要自然成因,因其受制于主导风向而且分布随机,作用效应与温室结构形体、表面粗糙度等因素密切相关,是一种复杂的结构动荷载.为研究不同风向风荷载(0°、30°、60°、90°)对不同跨数(1跨、3跨、5跨、10跨)的温室结构直面风压的作用效应,运用ICEMCFD及Fluent软件进行数值模拟实验.结果表明:风力和风向角相同时,1跨结构压力最大,其余3种跨度风压相对较小且差异性不显著;斜向来的风向是对温室结构最不利的情况,而且30°和60°风向角形成的局部高负压比0°和90°明显增大.

Protected agriculture is a highly modernized and intensive mode of agricultural production and greenhouses are the most effective and most widely used facilities in protected agriculture.In the current research,we often looks at the structural stability of greenhouses as well as the measurement and control of indicators of greenhouses′interior conditions.Wind load,the main natural cause of structural damage to greenhouses,is a complex dynamic load on this structure because it is subject to prevailing wind direction and is distributed randomly and wind effects are closely related to the shape and surface roughness of a greenhouse and some other factors.In this study,a numerical simulation has been conducted by means of ICEMCFD and Fluent to investigate the effects of winds from different directions（0°,30°,60°,and 90°）on the walls of greenhouses with different numbers of spans（1,3,5,and 10spans）.Results show that,under the winds with the same wind strengths and from the same directions,the single-span greenhouse is subjected to the highest structural pressure while the other three structures underwent relatively low and similar pressures.Moreover,oblique winds are the most unfavorable conditions to the greenhouses and the winds from the directions of 30°and 60°caused significantly higher local negative pressures than the winds from the directions of 0° and 90°did.