The influence of wind direction change on the internal environment of greenhouse group
In order to investigate the effects of changing incoming wind direction on the internal environment of a greenhouse cluster consisting of several plastic greenhouses,a cluster of three greenhouses A,B,and C with hill-wall doors was investigated by using computational fluid dynamics(CFD)techniques.The effects of internal greenhouse ventilation rate,the average crop canopy temperature,and water vapour mass fraction under different wind directions were investigated,and the variations of crop canopy temperature and water vapour mass fraction inhomogeneities JT and JR were analysed.The results show that,the ventilation rate in the upwind greenhouse is greater than that in the downwind greenhouse,and the increase of γ leads to a decrease of effective ventilation area of the greenhouse,resulting in a gradual decrease in the greenhouse ventilation rate,and the decrease is more obvious when γ>20°.Influenced by crop evaporation and external airflow,as γ increases,the JT and JR of each greenhouse show different patterns of change;the JT of the three greenhouses.i.e.,A,B,and C,reaches its maximum at γ = 20°,40°,and 60°,respectively.The maximum of JR of greenhouses A and C,appear at γ = 60°,while for greenhouse B,JR reaches its maximum at γ = 0°.And the increase of γ significantly influenced both JT and JR.
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万方数据
维普
