Flow in tidal rivers periodically propagates upstream or downstream under tidal influence. Hydrodynamic models based on the Saint-Venant equations （the SVN model） are extensively used to model tidal rivers. A force-...Flow in tidal rivers periodically propagates upstream or downstream under tidal influence. Hydrodynamic models based on the Saint-Venant equations （the SVN model） are extensively used to model tidal rivers. A force-corrected term expressed as the combination of flow velocity and the change rate of the tidal fevel was developed to represent tidal effects in the SVN model. A momentum equation incorporating with the corrected term was derived based on Newton＇s second law. By combing the modified momentum equation with the continuity equation, an improved SVN model for tidal rivers （the ISVN model） was constructed. The simulation of a tidal reach of the Qiantang River shows that the ISVN model performs better than the SVN model. It indicates that the corrected force derived for tidal effects is reasonable; the ISVN model provides an appropriate enhancement of the SVN model for flow simulation of tidal rivers.展开更多
Data assimilation(DA)is a technique that integrates multisource observational data with numerical models to enhance simulation accuracy and optimize data utilization.Its core principle involves correcting biases in mo...Data assimilation(DA)is a technique that integrates multisource observational data with numerical models to enhance simulation accuracy and optimize data utilization.Its core principle involves correcting biases in model simulations using observational data while automatically selecting the most reliable observations.In essence,DA employs mathematical techniques to refine simulations,ensuring they reflect real-world measurements more accurately.展开更多
基金supported by the National Key Technologies R&D Program of China for the Eleventh Five-Year Plan Period (Grant No. 2008BAB29B08-02)the Program for the Ministry of Education and State Administration of Foreign Experts Affairs of China (Grant No. B08408)
文摘Flow in tidal rivers periodically propagates upstream or downstream under tidal influence. Hydrodynamic models based on the Saint-Venant equations （the SVN model） are extensively used to model tidal rivers. A force-corrected term expressed as the combination of flow velocity and the change rate of the tidal fevel was developed to represent tidal effects in the SVN model. A momentum equation incorporating with the corrected term was derived based on Newton＇s second law. By combing the modified momentum equation with the continuity equation, an improved SVN model for tidal rivers （the ISVN model） was constructed. The simulation of a tidal reach of the Qiantang River shows that the ISVN model performs better than the SVN model. It indicates that the corrected force derived for tidal effects is reasonable; the ISVN model provides an appropriate enhancement of the SVN model for flow simulation of tidal rivers.
基金supported by the National Natural Science Foundation of China(Grant No.42125502)the National Key Research and Development Program of China(Grant No.2024YFF0807903)。
文摘Data assimilation(DA)is a technique that integrates multisource observational data with numerical models to enhance simulation accuracy and optimize data utilization.Its core principle involves correcting biases in model simulations using observational data while automatically selecting the most reliable observations.In essence,DA employs mathematical techniques to refine simulations,ensuring they reflect real-world measurements more accurately.
