Adaptive Time Stepping–Operator Splitting Strategy to Couple Implicit Numerical Hydrodynamic and Water Quality Codes

Abstract

Hydrodynamic and water quality codes have been frequently linked. These have typically been linked with both the hydrodynamic and water quality models using similar explicit time steps, but for long-term simulations implicit models are required. The water quality codes linked to these hydrodynamic codes are forced to perform their computations using the hydrodynamic time step even though utilizing the same might result in drifting of the water quality solution. This technical note presents the development and testing of an operator splitting–derived method for linking hydrodynamic and water quality codes with adaptive time stepping. The resulting method provides high-fidelity solutions that compare well with analytic solutions and lends itself for extension to various other transported quantities.