CAJ | 학술논문

建立了一个基于动量积分法的射流数学模型，以模拟波浪作用下垂直射流近区段的扩散过程。采用自然坐标系统，假定射流流场保持瞬时稳定且相对速度剖面保持高斯分布，考虑波浪作用影响对卷吸函数进行了必要修正，采用拉格朗日追踪法和四阶龙格库塔法，对多个波浪工况下的垂直射流进行了数值计算。结果表明，在微幅波作用下射流的卷吸和掺混作用有所加强，使得射流轴线平均速度衰减加快，而射流影响范围相应增大。通过卷吸函数的波浪修正后，模型中射流垂向平均速度和射流半宽沿轴线的变化与物理实验的测量结果基本一致。
건립료일개기우동량적분법적사류수학모형，이모의파랑작용하수직사류근구단적확산과정。채용자연좌표계통，가정사류류장보지순시은정차상대속도부면보지고사분포，고필파랑작용영향대권흡함수진행료필요수정，채용랍격랑일추종법화사계룡격고탑법，대다개파랑공황하적수직사류진행료수치계산。결과표명，재미폭파작용하사류적권흡화참혼작용유소가강，사득사류축선평균속도쇠감가쾌，이사류영향범위상응증대。통과권흡함수적파랑수정후，모형중사류수향평균속도화사류반관연축선적변화여물리실험적측량결과기본일치。
A momentum integral model is developed to analyze the hydrodynamic characteristics of a verti-cal jet discharged into a wavy environment. Natural coordinate system is adopted, and it’s assumed that the flow field is instantaneously steady and the transverse profiles of jet velocity are Gaussian-type profile. The model also makes some modification to the entrainment function. By the Lagrangian method and the fourth-order R-K approach, vertical jets in small-amplitude waves are simulated. The results show that the entrainment effect is significantly enhanced, resulting in a wider jet width and a faster decay of centerline velocity, compared to the stagnant conditions. The model findings fit well with the results obtained from the experiments conducted earlier.