Morphological Model Setup | Tidal FlatsMorphological Model Setup | Tidal Flatshttps://oss.deltares.nl/c/message_boards/find_thread?p_l_id=1806675&threadId=3024422020-09-19T19:39:01Z2020-09-19T19:39:01ZMorphological Model Setup | Area of InterestOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3077192013-07-29T16:04:15Z2013-07-29T15:58:56ZHi there,<br /><br /><br />I am progressing on the model and started looking at the NESTING possibilities for the Model.<br /><br />I have supplemental high resolution bathymetry data for the area of interest in my domain. <br /><br />Currently I am a little puzzled as to how one could mesh it in order for it to work smoothly. <br /><br />I attached an overview of the area. It features a coastline with artificial structures and adjacent tidal flats.<br /><br />I am thankful for suggestions on how to mesh this the best possible way.<br /><br />Cheers,<br /><br /><br />OliverOliver Lojek2013-07-29T15:58:56ZRE: Morphological Model Setup | Tidal Flats | Domain sizeQinghua Yehttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3057662013-07-24T09:24:34Z2013-07-24T09:24:34ZHi Oliver,<br /><br />I would say it should be ok, but still depends on the situation.<br /><br />Regards,<br /><br />QinghuaQinghua Ye2013-07-24T09:24:34ZMorphological Model Setup | Tidal Flats | Domain sizeOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3053062013-07-23T16:02:09Z2013-07-23T16:02:09ZAnd a totally different question in general - are 8 km of tidal flat in both directions enough for the tide to realistically simulate the morphological processes regarding the different modes of entrainment?<br /><br />Given is fine, non-cohesive sediment < 63 µm comprise between 100 - 70 % of sediment probes taken on site.<br /><br />Average water level amounts to 5.00 m with a tidal amplitude of 2.75 m.<br /><br />Current velocities range between 0.3 - 1.0 m/s within the domain over the tide.<br /><br /><br />Regards,<br /><br /><br />OliverOliver Lojek2013-07-23T16:02:09ZRE: Morphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3052392013-07-24T08:41:33Z2013-07-23T14:57:45ZHi Qinghua,<br /><br />it worked - the model runs smoothly and the output looks quite good.<br /><br />Regards,<br /><br />OliverOliver Lojek2013-07-23T14:57:45ZRE: Morphological Model Setup | Tidal FlatsQinghua Yehttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3051892013-07-23T13:36:54Z2013-07-23T13:36:54ZHi Oliver and Dmitry,<br /><br />Yes, I would say to decrease the time step, to make the grid coarser, or to increase the grid orthogonality, and so on, could be helpful to remove the warning about the big water level gradient and velocity gradient.<br /><br />Delft3D used a lot of numerical tips to stabilize the solution. Officially the Cr number can be as big as 10. I would not trust the results if the Cr number is bigger than that.<br /><br />But there is no general solution to solve everybody's modeling problem. So in that sense, we still have to tune the model and modelling stays as an art. The modeller stays as artists. <img alt="emoticon" src="https://oss.deltares.nl/o/deltares-theme.war/images/emoticons/happy.gif" ><br /><br />Keep us update and see what comes out of your work as an artist...<br /><br />Regards,<br /><br />QinghuaQinghua Ye2013-07-23T13:36:54ZRE: Morphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3050042013-07-23T07:47:16Z2013-07-23T07:14:43ZHi Dmitry,<br /><br /><br />good to know - I was wondering already seemed way to small.<br /><br />I had the model running but it gave me multiple errors on too harsh velocity changes. I checked the courant numbers but QUICKIN suggested negative values.<br /><br />e.G.:<br /><br />*** WARNING Velocity change too high > 5.00 m/s (per 0.5 DT) after 18020 <br />*** timesteps in the following points:<br />*** WARNING Velocity change too high > 5.00 m/s (per 0.5 DT) after 18021 <br /><br /><br /><br />That is why I assumed I better coarsen the grid a bit. I did coarsen it and othogonalized it and checked the triangulation and so forth - now I get courant numbers around 0.276 all over the domain (see PNG).<br />I'll reduce the runtime and see if the inconsistencies are gone.<br /><br /><br />Regards,<br /><br /><br />OliverOliver Lojek2013-07-23T07:14:43ZRE: Morphological Model Setup | Tidal FlatsDmitry Kushnirhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3048302013-07-22T18:32:19Z2013-07-22T18:31:18ZHi Oliver,<br /><br />I think that modeling guide about computational grid refer to 20'000 cells per one layer. I'm now running simulations on a domain consisting of 244x52 grid cells and with 15 sigma-layers this will be similar to your model. For now it was running without errors. Probably you don't need to coarse your grid. Have you tried to check the courant number in quickin for your bathymetry and time step?<br /><br />Regards,<br /><br />DmitryDmitry Kushnir2013-07-22T18:31:18ZRE: Morphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3047682013-07-22T15:50:15Z2013-07-22T15:50:15ZOkay - for what ever reason the previous GUI version (4.00.01) works the Triangulation Check independant of the size.<br />For the homogeneously fine grid I got the following values.<br /><br />Thus the grid comprises 235 X 91 = 21'385 Cells - I usually introduce 10 vertical layers given a typical water level of about 4 m. Eventually it holds 213'850 Cells to be calculated per step.<br />Reading the manual and the modelling guidelines I found that a typical grid comprises 20'000 cells. Therefore, I guess I will have to coarsen the grid quite a bit and add some nesting for the area of interest as suggested by Qinghua earlier.<br /><br /><br />Interpolation Check by Reverse Interpolation<br />*************************************************<br />Mean Interpolation Error : 0.823365E-01 [m]<br />Mean Abs Interpolation Error : 0.365152E+00 [m]<br />Maximum Error Value : 0.528059E+03 [m]<br />Number of Samples Checked : 80615 [-]<br /><br />Actual and Maximum Dimensions of Data<br />****************************************************************<br />Data Type : Actual Maximum<br />Grid M-Direction : 235 235<br />Grid N-Direction : 91 91<br />Samples : 102370 102445<br />Land Boundary : 0 1<br />Polygon : 0 1<br />Depth Points in Polygon : 21381 21385<br />Second Depth Points in Polygon : 0 21385<br />Samples in Polygon : 102370 102445<br /><br />Volumes and Areas below Reference Level<br />*************************************************<br />Volume Grid below 0.0[m]: 4.578562E+08[m3]<br />Grid Area below 0.0[m]: 1.368022E+08[m2]<br />Polygon Area : 0.000000E+00[m2]Oliver Lojek2013-07-22T15:50:15ZRE: Morphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3047092013-07-22T13:53:56Z2013-07-22T13:53:56ZI just tried to check the interpolation in RGFGRID. But RGFGRID crashes every time I click the button.<br />Does this routine only support a limited number of interpolated points aka. did I set the resolution too high for it to work recursively?<br /><br /><br />Kind regards,<br /><br /><br />OliverOliver Lojek2013-07-22T13:53:56ZRE: Morphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3046492013-07-22T12:45:28Z2013-07-22T12:44:59ZHi Qinghua,<br /><br /><br />you are correct, there is a tidal channel flowing through my area of interest.<br /><br />However, I need to get the model to run properly first before I can add Sediment and so on - currently I seem to get a lot of CFL related issues.<br />I have removed all physical processes and so far just have a tidal boundary forcing and that is it. I am modelling one week which takes about 2 minutes on my small server.<br /><br />The GUI suggested that the resolution was fairly high and the aspect ratio was fine as was the orthogonality. At some point however the Model seems to become instable and suggests Time steps of -0.147E01 Minutes.<br /><br />I reduced the timestep from 5 min to 2.5, 1, 0.5 and 0.25 min. This usually happens around 80 to 90 % of the calculation.<br /><br /><div class="lfr-code"><table><tbody><tr><td class="line-numbers" data-line-number="1"></td><td class="lines"><div class="line">*** MESSAGE Using UNESCO density formulation by default</div></td></tr><tr><td class="line-numbers" data-line-number="2"></td><td class="lines"><div class="line">*** MESSAGE Momentum solver cyclic method is specified</div></td></tr><tr><td class="line-numbers" data-line-number="3"></td><td class="lines"><div class="line">*** MESSAGE DRYFLP and DPSOPT both specified in MD-file. Using DPSOPT: MAX</div></td></tr><tr><td class="line-numbers" data-line-number="4"></td><td class="lines"><div class="line">*** MESSAGE Transport solver cyclic-method method is specified</div></td></tr><tr><td class="line-numbers" data-line-number="5"></td><td class="lines"><div class="line">*** WARNING File will not be created - Inconsistent comm. file times</div></td></tr><tr><td class="line-numbers" data-line-number="6"></td><td class="lines"><div class="line">*** MESSAGE Nodal factors updated at 2007-01-01 00:00:30.0000</div></td></tr><tr><td class="line-numbers" data-line-number="7"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.04 for (m,n,k) = (1,21,1), at nst = 10. Advised time step: 0.966E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="8"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.08 for (m,n,k) = (1,21,1), at nst = 11. Advised time step: 0.928E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="9"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.02 for (m,n,k) = (2,20,1), at nst = 11. Advised time step: -.980E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="10"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.18 for (m,n,k) = (2,17,7), at nst = 11. Advised time step: 0.848E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="11"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.10 for (m,n,k) = (3,16,7), at nst = 11. Advised time step: -.913E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="12"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.16 for (m,n,k) = (1,21,1), at nst = 12. Advised time step: 0.859E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="13"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.12 for (m,n,k) = (3,16,7), at nst = 12. Advised time step: -.896E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="14"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.40 for (m,n,k) = (2,18,9), at nst = 12. Advised time step: 0.713E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="15"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.24 for (m,n,k) = (3,16,8), at nst = 12. Advised time step: -.807E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="16"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.29 for (m,n,k) = (2,16,8), at nst = 13. Advised time step: 0.775E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="17"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.24 for (m,n,k) = (3,16,7), at nst = 13. Advised time step: -.806E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="18"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.37 for (m,n,k) = (2,16,9), at nst = 13. Advised time step: 0.729E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="19"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.32 for (m,n,k) = (3,15,1), at nst = 13. Advised time step: -.758E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="20"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in U-point equals 1.33 for (m,n,k) = (3,16,1), at nst = 14. Advised time step: 0.754E+00 minutes.</div></td></tr><tr><td class="line-numbers" data-line-number="21"></td><td class="lines"><div class="line">*** MESSAGE Courant number for U-velocity in V-point equals 1.28 for (m,n,k) = (3,15,1), at nst = 14. Advised time step: -.780E+00 minutes.</div></td></tr></tbody></table></div><br /><br />I have simulated waves with a 3G spectral model coupled to it on unstructured grids and unfortunately am not too familiar with curvilinear grids - are there any help resources for Delft3d on how to generate an appropriate mesh?Oliver Lojek2013-07-22T12:44:59ZRE: Morphological Model Setup | Tidal FlatsQinghua Yehttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3036092013-07-19T12:05:19Z2013-07-19T12:05:19ZHi Oliver,<br /><br />Looks like the area you are interested in has a tidal channel flowing in the area in an angle.<br /><br />I would suggest a model covering bigger area first. Then you may nest the smaller model to get correct boundary conditions. You may have to tune the model very careful about sediment transport at very shallow water.... The Flooding scheme is definitely sth you should try. Maybe also cutting cell technique.<br /><br />Regards,<br /><br />QinghuaQinghua Ye2013-07-19T12:05:19ZMorphological Model Setup | Tidal FlatsOliver Lojekhttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806675&messageId=3024412013-07-18T08:51:11Z2013-07-16T16:34:36ZHi there,<br /><br />I am setting up a model to simulate morphological long term processes.<br /><br />Currently I am looking at detailed meshing of tidal channels which end within the domain. Does anybody have any suggestions on how to mesh this?<br /><br /><br />Kind regards,<br /><br /><br />OliverOliver Lojek2013-07-16T16:34:36Z