中山大学学报（自然科学版）
中山大學學報（自然科學版）
중산대학학보（자연과학판）
ACTA SCIENTIARUM NATURALIUM UNIVERSITATIS SUNYATSENI
2014年
2期
142-147,152
,共7页
底边界层%泥沙交换%底床侵蚀率%有效沉降速度
底邊界層%泥沙交換%底床侵蝕率%有效沉降速度
저변계층%니사교환%저상침식솔%유효침강속도
bottom boundary layer%sediment exchange%bed erodibility%effective settling velocity
河口底边界层细颗粒泥沙运动往往受边界层内多种尺度的动力过程影响而变得十分复杂。由此，基于座底支架上的ADV与OBS，于2010年枯季在珠江磨刀门水道分别进行大、中、小潮的底边界层观测，对磨刀门水道底边界层湍流动力特征与小尺度泥沙交换过程进行研究。结果表明：悬沙有效沉速、床面切应力与底床侵蚀率的变化范围随着潮差的增大而增大；底床侵蚀率与平均流速变化规律相似，当流速小于0.3m/s时，侵蚀率基本保持在0.002 kg/m2左右，流速超过此临界值时，床面泥沙发生再悬浮。悬沙和床沙交换过程随着潮差增大而增强，且落潮时段强于涨潮时段。
河口底邊界層細顆粒泥沙運動往往受邊界層內多種呎度的動力過程影響而變得十分複雜。由此，基于座底支架上的ADV與OBS，于2010年枯季在珠江磨刀門水道分彆進行大、中、小潮的底邊界層觀測，對磨刀門水道底邊界層湍流動力特徵與小呎度泥沙交換過程進行研究。結果錶明：懸沙有效沉速、床麵切應力與底床侵蝕率的變化範圍隨著潮差的增大而增大；底床侵蝕率與平均流速變化規律相似，噹流速小于0.3m/s時，侵蝕率基本保持在0.002 kg/m2左右，流速超過此臨界值時，床麵泥沙髮生再懸浮。懸沙和床沙交換過程隨著潮差增大而增彊，且落潮時段彊于漲潮時段。
하구저변계층세과립니사운동왕왕수변계층내다충척도적동력과정영향이변득십분복잡。유차，기우좌저지가상적ADV여OBS，우2010년고계재주강마도문수도분별진행대、중、소조적저변계층관측，대마도문수도저변계층단류동력특정여소척도니사교환과정진행연구。결과표명：현사유효침속、상면절응력여저상침식솔적변화범위수착조차적증대이증대；저상침식솔여평균류속변화규률상사，당류속소우0.3m/s시，침식솔기본보지재0.002 kg/m2좌우，류속초과차림계치시，상면니사발생재현부。현사화상사교환과정수착조차증대이증강，차락조시단강우창조시단。
The movement of grain sediment within the bottom boundary layer is influenced by complicat-ed,multi-scale dynamic processes.Dynamic characteristics of turbulence and small-scale sediment ex-change process within the bottom boundary layer at modaomen channel are discussed based on bottom boundary layer observation data over various tide levels by using ADV and OBS in winter of 2010.The result shows that:① The ranges of sediment settling velocity,bottom stress and bed erodibility increase with tidal range.②Bed erodibility changes are similar to mean velocity.When velocity is less than 0.3 m/s,the bed erodibility remains at about 0.002 kg/m2 .If velocity is larger than 0.3 m/s,sediment will resuspend.③ Suspended sediment and bed sediment exchange process is enhanced with increasing tidal range,and it is stronger during ebb tide than during flood tide.
