CAJ | 학술논문

冲积河流的粗颗粒河床，具有较大的渗透性，河床渗透对明渠水流运动特性的影响不可忽视．通过水槽试验，研究了河床渗透对垂线流速分布的影响．距试验玻璃水槽进口10m处，设计一个长1．65m、宽0．7m的收缩段，由12层直径1cm的玻璃珠紧密有规则铺成，以模拟粗糙透水床面．其上下游铺上1层相同玻璃珠，形成粗糙度相同但不透水的床面．垂线流速分布通过激光多普勒测速仪及配套的高精度坐标架系统测量．试验施放了3种流量，分别在不透水和透水床面进行垂线流速分布测量．试验结果表明：1）不透水床面的垂线流速分布符合粗糙床面的对数分布公式；2）粗糙透水床面明渠流的垂线流速分布与不透水床面相似；3）相同水流条件下，透水床面的摩阻流速要大于不透水床面；4）透水床面的摩阻流速与积分常数的变化规律有待进一步研究．
충적하류적조과립하상，구유교대적삼투성，하상삼투대명거수류운동특성적영향불가홀시．통과수조시험，연구료하상삼투대수선류속분포적영향．거시험파리수조진구10m처，설계일개장1．65m、관0．7m적수축단，유12층직경1cm적파리주긴밀유규칙포성，이모의조조투수상면．기상하유포상1층상동파리주，형성조조도상동단불투수적상면．수선류속분포통과격광다보륵측속의급배투적고정도좌표가계통측량．시험시방료3충류량，분별재불투수화투수상면진행수선류속분포측량．시험결과표명：1）불투수상면적수선류속분포부합조조상면적대수분포공식；2）조조투수상면명거류적수선류속분포여불투수상면상사；3）상동수류조건하，투수상면적마조류속요대우불투수상면；4）투수상면적마조류속여적분상수적변화규률유대진일보연구．
A laboratory experimental research is reported, which considered effects of bed permeabili- ty on the velocity distribution of turbulent open-channel flow. The experiment was conducted in a glass-sided flume that was 20 m long, 0.8 m wide and 0. 6 m deep, and its bed was glued a layer of uniform marbles with a diameter of 1 cm. Located at a distance of 10 m from the upstream end of the flume was a rectangular recess that was 1.65 m long and 0. 7 m wide. The permeable bed is simulated in the recess where is well packed with eleven layers of the same marble. The velocity measurements were carried out using a laser Doppler velocimeter ( LDV, DANTEC) and the probe of the LDV was installed by a high resolution traversing system. The measurements were conducted under three flow conditions. Velocity distribution at 2 locations for impermeable bed and 3 for permeable bed were measured. The results show that the velocity distribution for impermeable bed follows the law of the wall when the reference level is lowered to 0. 25-diameter of the marble top. For permeable bed, its distribution is similar to that over impermeable bed, but with larger shear velocity and smaller integra- tion constant. Still, how the shear velocity and integration constant vary need further investigation.