人民黄河
人民黃河
인민황하
Yellow River
2015年
4期
119-122
,共4页
水舌%水力特性%流速分布%数值模拟
水舌%水力特性%流速分佈%數值模擬
수설%수력특성%류속분포%수치모의
water jet form%hydraulic characters%velocity distribution%numerical simulation
空中水舌的水力特性与下游雾化及冲刷密切相关,因此得到空中水舌形态、水舌扩散特性和断面流速分布等计算公式十分重要。对空中水舌进行三维数值模拟,在等宽出口形式下,通过改变来流断面水流弗劳德数Fr,重点研究了水舌紊动扩散规律、断面流速分布规律等,并采用理论推导法得到沿程断面平均流速的计算公式。研究结果表明:Fr值越大,水流沿程横向扩散越强烈;水舌横向扩散率初始较大,随着射距的增加,扩散率逐渐减小;水舌纵向厚度同射距近似呈直线关系;断面流速分布服从正态分布,且不同射距处的无量纲流速分布曲线可用同一条曲线表示。
空中水舌的水力特性與下遊霧化及遲刷密切相關,因此得到空中水舌形態、水舌擴散特性和斷麵流速分佈等計算公式十分重要。對空中水舌進行三維數值模擬,在等寬齣口形式下,通過改變來流斷麵水流弗勞德數Fr,重點研究瞭水舌紊動擴散規律、斷麵流速分佈規律等,併採用理論推導法得到沿程斷麵平均流速的計算公式。研究結果錶明:Fr值越大,水流沿程橫嚮擴散越彊烈;水舌橫嚮擴散率初始較大,隨著射距的增加,擴散率逐漸減小;水舌縱嚮厚度同射距近似呈直線關繫;斷麵流速分佈服從正態分佈,且不同射距處的無量綱流速分佈麯線可用同一條麯線錶示。
공중수설적수력특성여하유무화급충쇄밀절상관,인차득도공중수설형태、수설확산특성화단면류속분포등계산공식십분중요。대공중수설진행삼유수치모의,재등관출구형식하,통과개변래류단면수류불로덕수Fr,중점연구료수설문동확산규률、단면류속분포규률등,병채용이론추도법득도연정단면평균류속적계산공식。연구결과표명:Fr치월대,수류연정횡향확산월강렬;수설횡향확산솔초시교대,수착사거적증가,확산솔축점감소;수설종향후도동사거근사정직선관계;단면류속분포복종정태분포,차불동사거처적무량강류속분포곡선가용동일조곡선표시。
Hydraulic characteristics of water jet flow are closely related to atomization and scour of prototype. This means,the formulas which including form,the diffusion of qualities and velocity distribution of sections are important. This article simulated flow jet with the method of 3D numerical simulation and focused on turbulent diffusion laws and velocity distribution of sections by changing Froude number. Meanwhile theoretical formula calculation was adopted to get mean velocity formula. The results show that with the bigger Froude number,the more intense of transverse diffusion is,the greater the transverse diffusivity will be and gradually decreases with the distance to export increa-ses. The jet thickness is approximately linear to distance. The velocity distribution follows normal distribution. The results further enrich hy-draulic characteristics of water jet flow that can be used as a reference for design of engineering.