基于大涡模拟增设气动措施冷却塔风荷载频域特性  

Wind loads of frequency domain characteristics for large cooling towers with aerodynamic measures based on large eddy simulation

作　　者：柯世堂[1] 朱鹏[1] 

机构地区：[1]南京航空航天大学土木工程系,江苏南京210016

出　　处：《浙江大学学报（工学版）》2016年第11期2143-2149,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51208254);江苏省优秀青年基金资助项目(BK20160083);中央高校基本科研业务费专项资金资助项目(NS2016019);中国博士后基金资助项目(2013M530255);江苏省博士后基金(1202006B)联合资助项目

摘　　要：为了研究带气动措施的大型冷却塔风荷载频域特性,采用大涡模拟(LES)技术计算得到不同气动措施下冷却塔外表面风荷载时程,将典型断面的平均和脉动风压与国内外实测及风洞试验结果进行对比,验证了大涡模拟的有效性.对平均风压分布曲线、典型断面涡量图、脉动风荷载的功率谱、相关系数及相干函数等频域特性进行研究,分析不同气动措施对大型冷却塔外表面平均风压流场特性和脉动风压频域特性的影响.结果表明:增设气动措施导致塔筒下部进风口区域平均风压局部增大,以弧形导风板最明显;脉动风荷载能量主要集中在低频区域,迎风面测点脉动风能量相对较大;增设气动措施导致塔筒表面风荷载频谱特性更加复杂,风荷载功率谱出现多个峰值点;迎风区测点之间脉动风压相关性较高,增设气动措施对相关系数影响较大,其中导风板的相关系数均达到了0.62以上;测点之间相干性均表现出随频率上升而增大的趋势,并且频率达到0.4Hz后,相干函数接近1.Wind loads on cooling towers with different aerodynamic measures were obtained by means of large eddy simulation technique, in order to analyze the frequency domain characteristics of wind loads on large cooling towers with aerodynamic measures, The effectiveness of large eddy simulation was verified compared mean wind pressure and fluctuate pressure by actual measured and wind tunnel test. Then the wind loads on the contour of mean pressure and vorticity, power spectrum density, correlation and related functions were investigated in the characteristics of frequency domain. The effects of different aerodynamic measures on the characteristics of mean wind pressure flow field and the frequency domain of the fluctuating wind pressure on the surface of large cooling tower were analyzed. Results showed that aerodynamic measures leaded to the average wind pressure increases on lower part of tower inlet area, and arcshaped air guide plate was most evident. The fluctuating wind energy was concentrated on the low frequency, and the fluctuating wind loads on windward points had higher wind energy. The aerodynamic measures leaded to multiple peaks in power spectra of wind loads. The correlation of fluctuating wind pressure in windward area was higher, and aerodynamic measures had greater impact on correlation coefficients. The correlation coefficient of air guide plate were more than 0. 62%. The coherence between the measuring points was increased with the frequency, and the coherence function closed to 1 when frequency reached 0. 4 Hz.

关 键 词：大型冷却塔 气动措施 大涡模拟 流场分布 频域特性 

分 类 号：TU332[建筑科学—结构工程]