Study on Estimation of Turbulent Flow Structures Below Water Surface Based on Water Surface Data by Sequential Data Assimilation

Key Points

• The aim is to create a technology to visualize and estimate turbulent structures in river floods using surface data.
• Combined large-eddy simulation with a local ensemble transform Kalman filter
• Performed twin experiments on open channel turbulence
• Evaluated estimation performance from instantaneous fields and statistics
• Successfully reproduced instantaneous turbulent structures near the water surface
• Estimation accuracy decreased with depth, particularly below water surface scales
• Estimation performance was largely independent of the bottom conditions