CAJ | 학술논문

处理底坡项是计算浅水动力学的重要任务之一.针对传统的底坡项处理技术在大起伏地形上的不足,通过计算底坡项对水深和动量通量的影响,并进行相应的分解,构造了集成底坡项的近似Riemann求解器.该求解器具有强和谐性,即能保持任意流速下的恒定流状态.同时,能保证水深计算值非负,有利于计算的稳定性.考虑了干湿界面中固壁、漫流等情况,适应动边界模拟.算例研究结果表明,该求解器能准确地处理底坡项,保证水深非负,和谐性好,激波捕获能力强,适应干湿界面计算,可模拟复杂混合流态问题,因而具有较好的推广应用价值.
처리저파항시계산천수동역학적중요임무지일.침대전통적저파항처리기술재대기복지형상적불족,통과계산저파항대수심화동량통량적영향,병진행상응적분해,구조료집성저파항적근사Riemann구해기.해구해기구유강화해성,즉능보지임의류속하적항정류상태.동시,능보증수심계산치비부,유리우계산적은정성.고필료간습계면중고벽、만류등정황,괄응동변계모의.산례연구결과표명,해구해기능준학지처리저파항,보증수심비부,화해성호,격파포획능력강,괄응간습계면계산,가모의복잡혼합류태문제,인이구유교호적추엄응용개치.
The treatment of topography source terms (TST) is one of the important tasks in the computational shallow water dynamics. To overcome the shortage of conventional technology of dealing TST when facing big bottom step, An approximate Riemann solver was constructed,which integrates TST considering the influence of TST on both water depth and momentum flux, and then decompose them. The solver is well-balanced, which can preserve steady state under any water flow velocity. Meanwhile, it can guarantee nonnegative water depth that is preferable to keep computational stability. To treat with wetting/drying and achieve moving boundary simulation, some special methods are taken. Numerical results of some examples show that the solver can evaluate the effect of source terms accurately when maintaining depth nonnegative and is well-balanced. It also has an excellent shock-capturing ability, and can simulate the mixed flow exactly.