Hydrodynamics, salinity transport processes, and thermodynamics in Charlotte Harbor and its major tributaries in Florida, USA were simulated using a coupled three-dimensional (3D) and laterally averaged two-dimensional (2DV) hydrodynamic model named UnLESS, in support of the re-evaluation of minimum freshwater inflows for two water bodies in the system, namely the lower Peace River (LPR) and lower Shell Creek (LSC). The UnLESS model involves a dynamic and two-way coupling of the 3D unstructured Cartesian grid model UnLESS3D (Chen, 2011) with the laterally averaged model LAMFE (Chen, 2003a) using a semi-implicit scheme named the free-surface correction (FSC) method (Chen, 2003b.)

The simulation period was January 2013 through August 2014, during which best real-time data of water elevation, current, salinity, and temperature at five measurement stations within the simulation domain were available. Comparisons of model results with these real-time field data show that UnLESS is capable of simulating hydrodynamics, salinity transport processes, and thermodynamics well in the Charlotte Harbor estuary. Good matches of model results with measured data suggest that both estimated ungauged flows and downstream boundary conditions were reasonable. Major physical characteristics in the Charlotte Harbor system are correctly simulated by the UnLESS model. It is demonstrated that the dynamically coupled 3D-2DV model UnLESS is robust and very efficient for complex systems such as Charlotte Harbor, which has a large waterbody with islands and several narrow and meandering tributaries.

为了支持这一目标，我们使用名为UnLESS的三维（3D）和横向平均二维（2DV）耦合水动力模型对夏洛特港及其主要支流在美国佛罗里达州的水动力，盐分输送过程和热力学进行了模拟。评估系统中两个水体（即下和平河（LPR）和下壳河（LSC））的最小淡水流入量。UnLESS模型涉及3D非结构化笛卡尔网格模型UnLESS3D（Chen，2011）与横向平均模型LAMFE（Chen，2003a）的动态双向耦合，该模型使用称为自由表面校正（FSC）的半隐式方案。方法（Chen，2003b。）

模拟期为2013年1月至2014年8月，在此期间，可以获取模拟域内五个测量站的水位，电流，盐度和温度的最佳实时数据。模型结果与这些实时现场数据的比较表明，UnLESS能够很好地模拟夏洛特港河口的流体动力学，盐分传输过程和热力学。模型结果与实测数据的良好匹配表明，估计的未吞水流量和下游边界条件都是合理的。夏洛特港口系统的主要物理特征可以通过UnLESS模型正确模拟。事实证明，动态耦合的3D-2DV模型UnLESS对于诸如夏洛特港，