空气动力学学报
空氣動力學學報
공기동역학학보
ACTA AERODYNAMICA SINICA
2015年
1期
91-98
,共8页
李永乐%唐浩俊%陈宁%廖海黎
李永樂%唐浩俊%陳寧%廖海黎
리영악%당호준%진저%료해려
塔周长吊索%桥塔尾流%涡激共振%卓越频率%CFD
塔週長弔索%橋塔尾流%渦激共振%卓越頻率%CFD
탑주장조색%교탑미류%와격공진%탁월빈솔%CFD
long suspenders nearby the pylon%wake of bridge tower%vortex-induced vibra-tion%dominant frequency%CFD
悬索桥桥塔周围的长吊索自振频率较低，且易受桥塔尾流的干扰从而容易发生振动。吊索的安全直接关系着桥梁结构的安全，以实际工程为背景，采用 CFD 数值模拟方法并选择 SST k-ω湍流模型对二维桥塔断面及吊索断面的非定常绕流进行了分析。首先，计算了桥塔和吊索各自的气动特性，并与相关文献的结果进行了对比。在验证分析方法可靠性的基础上，进一步研究了不同来流风速、风向角下，桥塔尾流对塔周长吊索气动特性的干扰。通过对流场特征及吊索气动力的变化规律进行分析，研究了桥塔尾流作用下塔周长吊索发生涡振的可能性。研究结果表明：在相当大的风向角范围内，桥塔脱落的旋涡会对吊索气动特性产生控制作用，从而导致吊索阻力系数和升力系数的变化频率等于桥塔的旋涡脱落频率，使吊索在低风速下存在发生涡激共振的可能性。
懸索橋橋塔週圍的長弔索自振頻率較低，且易受橋塔尾流的榦擾從而容易髮生振動。弔索的安全直接關繫著橋樑結構的安全，以實際工程為揹景，採用 CFD 數值模擬方法併選擇 SST k-ω湍流模型對二維橋塔斷麵及弔索斷麵的非定常繞流進行瞭分析。首先，計算瞭橋塔和弔索各自的氣動特性，併與相關文獻的結果進行瞭對比。在驗證分析方法可靠性的基礎上，進一步研究瞭不同來流風速、風嚮角下，橋塔尾流對塔週長弔索氣動特性的榦擾。通過對流場特徵及弔索氣動力的變化規律進行分析，研究瞭橋塔尾流作用下塔週長弔索髮生渦振的可能性。研究結果錶明：在相噹大的風嚮角範圍內，橋塔脫落的鏇渦會對弔索氣動特性產生控製作用，從而導緻弔索阻力繫數和升力繫數的變化頻率等于橋塔的鏇渦脫落頻率，使弔索在低風速下存在髮生渦激共振的可能性。
현색교교탑주위적장조색자진빈솔교저，차역수교탑미류적간우종이용역발생진동。조색적안전직접관계착교량결구적안전，이실제공정위배경，채용 CFD 수치모의방법병선택 SST k-ω단류모형대이유교탑단면급조색단면적비정상요류진행료분석。수선，계산료교탑화조색각자적기동특성，병여상관문헌적결과진행료대비。재험증분석방법가고성적기출상，진일보연구료불동래류풍속、풍향각하，교탑미류대탑주장조색기동특성적간우。통과대류장특정급조색기동력적변화규률진행분석，연구료교탑미류작용하탑주장조색발생와진적가능성。연구결과표명：재상당대적풍향각범위내，교탑탈락적선와회대조색기동특성산생공제작용，종이도치조색조력계수화승력계수적변화빈솔등우교탑적선와탈락빈솔，사조색재저풍속하존재발생와격공진적가능성。
The long suspenders nearby the tower of suspension bridge are prone to produce vibration performance in the wake of bridge tower due to their low natural frequencies.The sus-pender safety is closely related to the structural safety of bridge.The CFD numerical simulation was adopted and the SST k-ω turbulence model was chosen to analyze the unsteady flow around a 2D bridge tower and a 2D suspender according to a practical suspension bridge.First,the respec-tive aerodynamic characteristic of the bridge tower and the suspender was calculated and com-pared with the results of related literatures.The effects of the wake of bridge tower on the aero-dynamic characteristics of long suspenders nearby the pylon were analyzed under the condition of various wind velocities and directions after checking the reliability of the analysis method.The possibility of vortex-induced vibration of long suspenders nearby the tower in the wake of bridge tower was researched by analyzing the flow field characteristics and the change of aerodynamic forces of suspenders.The results indicate that vortex shedding from bridge tower has a strong influence on aerodynamic characteristics of suspenders at a wide range of wind directions,which may lead to vortex-induced vibration of suspenders at low wind velocity because the frequencies of drag and lift coefficient of suspenders are close to the frequency of vortex shedding from bridge tower.
