防风网气动特性参数的试验研究

防风网气动特性参数是防风网结构设计中的重要参数.通过风洞试验的方法研究了透风率分别为29.9%和35.4%的蝶形、平板两类防风网的静力风荷载气动特性参数.结果表明,防风网风载体型系数背风面为负值,其绝对值远大于迎风面;迎风面风载体型系数,当透风率较小时为负值,较大时为正值,即防风网向后的吸力是主要作用力. 防风网的压力损失系数、风载体型系数和阻力系数相互紧密联系,其值具有一致性,随着前者的提高,后两者的值也提高,即防风抑尘效果越好,抗风安全性越差.防风网结构设计时,要统筹兼顾,权衡利弊,选其最佳结合点.

Experimental study on the aerodynamic characteristic parameter of windbreak

The paper is to present the results of our experimental research results on the aerodynamic characteristic parameters in wind-breaking net wind resistance. Though so far few relevant research data can be found in this connection, we do believe it is badly in need of pushing the research with the wind tunnel testing and experiments so as to produce due static wind load aerodynamic characteristic parameters. So far we have found that two types of wind leak ratio with the papilionaceous and flat windbreak net were respectively 29.9%, 35.4%. The results of our experiments show that the wind shape factors are negative with large absolute number at the wind-free side whereas positive at the windward side. Furthermore, the factor proves negative if the wind leak ratio is small, whereas it would be positive if the wind leak ratio is large. Therefore, the wind load of windbreak net is mainly represented as a kind of suction force. On the other hand, when the wind pressure loss coefficient increases, the wind shape factor and wind drag force coefficient would in turn rise in a remarkable consistency. Thus, the better effect of windbreak and the weaker repression performance, the worse or weaker the wind resistance capability would become. Therefore, the best project should be determined by selecting the best harmony of the wind load and windbreaking effect in the structured wind resistance designation. In a word, the results of this paper can be taken as a reference to the actual windbreak net wind resistance designation so as to obtain the optimal aerodynamic characteristic parameters.