CCHE3D Flow Model
CCHE3D is a finite element based model for simulating free surface turbulent flows. Most of its applications are near-field flow and sediment transport around hydraulic structures. The simulated cases with measured experimental data have shown the accuracy and reliability of the model. The following list shows the capabilities of the model:
- Non-uniform quadrilateral grid
- collocation approach
- Partially staggered pressure grid
- Hydro-static/dynamic pressure
- Free surface
- Wet/dry moving boundary
- Modulated coding method
Simulated 3D flow field visualized by vectors, tracer lines, bed shear stress and water surface contours (right).
Spur dikes are a useful structure to protect stream banks from erosion and to train rivers for better navigation conditions.
CCHE3D has simulated the turbulent flows around spur dikes. The velocity data measured at National Sedimentation Lab, USDA, have used to check the model’s accuracy.
Overall agreement of the simulated and the measured total velocity at 2592 points around the submerged dike (above).
Quantitative comparison of measured and simulated velocity vertical profiles in three sections along the channel (right).
Inland water transportation is important to the economy. Barge navigation in curved river channels may be difficult because of the helical secondary current. CCHE3D has been applied to simulate the flow conditions in the Mississippi River and evaluate the effectiveness of the instream structures for improving navigation conditions of the channel bendway. The model was first validated using field velocity data and then compared the simulated secondary flow distributions before and after the installation of submerged weirs.
Tow boat barges in the Mississippi River
Simulated 3D velocity distribution in the channel bendway
Comparison of measured and simulated velocities
CCHE3D has been validated using detailed experimental data.
The following is a 180 degree flume. Detailed 3D velocity data in multiple cross-sections and along multiple vertical lines were measured.
Measured velocity data in a large curved experimental channel with trapezoidal shaped cross-section were used to validate the CCHE3D model.
The channel bed is covered with riprap rocks. The model predicted channel velocities agreed well with the measurements.
The flow discharge for this particular simulation was Q=4.24m3/s.