CAJ | 학술논문

该文采用三维数值模型研究风应力对水流运动和摩阻特性的影响。首先通过试验数据验证了数值模型对风生流结果的合理性；然后通过平底水槽的数值试验，研究了风应力的变化，尤其是在风向顺流和风向逆流条件下，对于定常水流涡黏系数分布、流速分布、雷诺切应力分布以及底部摩阻的影响。发现传统使用广泛的涡黏系数抛物线分布在风向顺流条件下基本与紊流模型结果吻合，而在风向逆流条件下，尤其是风应力较小情况下，抛物线分布与紊流模型结果有相当的偏差。流速分布则和传统双对数分布基本吻合，但须考虑风生流和定常流之间的相互作用，而不能简单看成两者间的线性叠加。雷诺切应力基本符合线性分布。底部摩阻受风生底流的影响，在平底条件下，风向顺流会减小底部摩阻，而风向逆流则会增加底部摩阻；但在非平底条件下，只有在较深处规律和平底类似，而在较浅处，风向顺流也会增加底部摩阻。
해문채용삼유수치모형연구풍응력대수류운동화마조특성적영향。수선통과시험수거험증료수치모형대풍생류결과적합이성；연후통과평저수조적수치시험，연구료풍응력적변화，우기시재풍향순류화풍향역류조건하，대우정상수류와점계수분포、류속분포、뢰낙절응력분포이급저부마조적영향。발현전통사용엄범적와점계수포물선분포재풍향순류조건하기본여문류모형결과문합，이재풍향역류조건하，우기시풍응력교소정황하，포물선분포여문류모형결과유상당적편차。류속분포칙화전통쌍대수분포기본문합，단수고필풍생류화정상류지간적상호작용，이불능간단간성량자간적선성첩가。뢰낙절응력기본부합선성분포。저부마조수풍생저류적영향，재평저조건하，풍향순류회감소저부마조，이풍향역류칙회증가저부마조；단재비평저조건하，지유재교심처규률화평저유사，이재교천처，풍향순류야회증가저부마조。
In this paper, a 3D finite-volume numerical model is developed and employed for the investigation on flow motion and friction characteristics influenced by the wind stress. Firstly, numerical results are compared with laboratory experiments and the numerical model is validated. Numerical tests are then performed to investigate the effect of the wind stress on flow motion and friction resistance characteristics. The vertical distribution of eddy viscosity coefficient, velocity and Reynolds shearing stress as well as the friction resistance on the bottom, under the downstream and the upstream wind respectively, are studied through the tests. It is found that the widely used parabolic vertical profile of eddy viscosity coefficient agrees with the model results under the downstream wind but deviates from the model results under the upstream wind especially the wind stress is not so much. The vertical profile of the streamwise velocity can be depicted by the double log law. However, it can not be considered as the sum of the wind driven flow and the stready flow because of the nonlinear interaction in the eddy viscosity. The vertical distribution of Reynolds shearing stress is nearly linear, which verifies the assumption in classical theory of wind-driven flow. The friction resistance on bottom is affected by the wind driven bottom current. In a flat bathymetry, the friction resistance decreased when the wind stress is downstream and increased when the wind is upstream. Nevertheless, this rule is true only in deep water. In shallow water, the friction resistance may also increase with the downstream wind.