Set the maximum erodible depth to 0 or the minimum erodible elevation to the thalweg elevation in the Initial conditions tab in the sediment editor. This will cause some oscillation, but it will only deposit, it will not erode below the original bed.
Hello Pheng, I saw your comment on the dam breach videos. We will be releasing an entire, online, 2D class with version 6.2 that will include a dam breach workshop and several talks. Look for it in the 6.2 release notes.
Cell size :2m Input hydrograph :1 hr interval I varied computational time step 10 min to 1 second, maximum courant no 2 Minimum courant no 0.95 But this couldn't work for run. Please suggest me how to make stable model?? 🙏🙏
Hello Mr. Stanford Gibson. I am trying to model sediment transport with a slope >0.04 which makes the model unstable and produces an unrealistic shape (erosion >5 meters). Is there a way to make the hecras sediment transport analysis run well on the model with a slope >0.04 (Extrem slope)? thanks before
@@stanfordgibson 1D sediment transport model sir,..;then I tried to reduce the slope to 0.02 by modifying the cross section and the model became stable. but made the model different from the actual river conditions.
@@stanfordgibson When slope >0.04 (actual model) . There is always a critical depth that causes the warning "One or more cross section(s) eroded to the bottom" in some cross sections. When I add a deeper "max depth" to the sediment data to overcome the warning, the model also becomes unstable following the input "max depth" data.
@@anggaeko299 is it unsteady or quasi unsteady? Have you tried different transport functions? It sounds like there’s a mismatch between the slope, the transport function, and the bed material. It’s pretty common in steep models to over erode if there’s a mismatch between the bed material and the transport function. Steep slopes are often outside of the range of the transport function, so you may have to coarsen the bed artificially to compensate. Try different transport functions (among those intended for the bed material you have) to see which one works best, and you might adjust the transport function with the calibration tools
Stanford, the way you teach your classes are amazing. You are awesome! Keep it up!
From Brazil.
I'am very grateful for people like you.
Thanks sir. thats helpful for ma paper.
How to solve the error,
Minimum error exceds allowable tolerance at ???
I am from Afrika Ethiopian 🇪🇹
your Videos are very helpful. Stanford, please how do you model sediment accumulation in a concrete lined river channel
Set the maximum erodible depth to 0 or the minimum erodible elevation to the thalweg elevation in the Initial conditions tab in the sediment editor. This will cause some oscillation, but it will only deposit, it will not erode below the original bed.
Many thanks for sharing this VDO
Hello Pheng, I saw your comment on the dam breach videos. We will be releasing an entire, online, 2D class with version 6.2 that will include a dam breach workshop and several talks. Look for it in the 6.2 release notes.
Love your videos! Any chance you can increase the volume on your mic? Thanks so much!
Sure...I can try. I'm still learning those settings :)
Thanks, you help me a lot
Cell size :2m
Input hydrograph :1 hr interval
I varied computational time step 10 min to 1 second, maximum courant no 2
Minimum courant no 0.95
But this couldn't work for run.
Please suggest me how to make stable model?? 🙏🙏
Hello Mr. Stanford Gibson. I am trying to model sediment transport with a slope >0.04 which makes the model unstable and produces an unrealistic shape (erosion >5 meters). Is there a way to make the hecras sediment transport analysis run well on the model with a slope >0.04 (Extrem slope)? thanks before
Is it a 1D or 2D sediment model?
@@stanfordgibson 1D sediment transport model sir,..;then I tried to reduce the slope to 0.02 by modifying the cross section and the model became stable. but made the model different from the actual river conditions.
@@stanfordgibson When slope >0.04 (actual model) . There is always a critical depth that causes the warning "One or more cross section(s) eroded to the bottom" in some cross sections.
When I add a deeper "max depth" to the sediment data to overcome the warning, the model also becomes unstable following the input "max depth" data.
@@anggaeko299 is it unsteady or quasi unsteady? Have you tried different transport functions? It sounds like there’s a mismatch between the slope, the transport function, and the bed material. It’s pretty common in steep models to over erode if there’s a mismatch between the bed material and the transport function. Steep slopes are often outside of the range of the transport function, so you may have to coarsen the bed artificially to compensate. Try different transport functions (among those intended for the bed material you have) to see which one works best, and you might adjust the transport function with the calibration tools
@@stanfordgibson I use quasi unsteady sir. I've also used all transport functions.
How to adjust the transport function with the calibration tools ?