Conservation - Revision history

Yjzhang at 20:51, 18 November 2025

2025-11-18T20:51:04Z

Yjzhang at 20:49, 18 November 2025

2025-11-18T20:49:49Z

Yjzhang at 17:21, 18 December 2014

2014-12-18T17:21:00Z

Yjzhang at 20:24, 4 June 2014

2014-06-04T20:24:14Z

Yjzhang: Created page with "Volume conservation is not enforced in SELFE but the error is generally small. Mass conservation is enforced with upwind/TVD transport. It's important to use proper method i..."

2014-06-04T20:22:14Z

Created page with "Volume conservation is not enforced in SELFE but the error is generally small. Mass conservation is enforced with upwind/TVD transport. It's important to use proper method i..."

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Volume conservation is not enforced in SELFE but the error is generally small. Mass conservation is enforced with upwind/TVD transport.

It's important to use proper method in checking the volume conservation. In particular, you should make use of the flag consv_check in param.in, instead of calculating flows using the outputs yourself. This is because the velocity outputs have interpolated from side centers to nodes.

Another thing to be aware of is the boundary condition. For example, the imposed river flow is conserved downstream, but if you also impose the elevation b.c., this is not the case anymore. The elev. b.c. as an essential b.c. over-rules the flow b.c. (a Neumann b.c.).

← Older revision		Revision as of 20:51, 18 November 2025
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	Another thing to be aware of is the boundary condition. For example, the imposed river flow is conserved downstream, but if you also impose the elevation b.c., this is not the case anymore. The elev. b.c. as an essential b.c. over-rules the flow b.c. (a Neumann b.c.).		Another thing to be aware of is the boundary condition. For example, the imposed river flow is conserved downstream, but if you also impose the elevation b.c., this is not the case anymore. The elev. b.c. as an essential b.c. over-rules the flow b.c. (a Neumann b.c.).

−	[~~Here](~~https://ccrm.vims.edu/yinglong/SVN_large_files/Mass-conservation-in-SCHISM-and-test-cases.pdf) is a document that describes mass conservation with settling velocity.	+	[https://ccrm.vims.edu/yinglong/SVN_large_files/Mass-conservation-in-SCHISM-and-test-cases.pdf Here] is a document that describes mass conservation with settling velocity.

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 Volume conservation is not enforced in SCHISM but the error is generally small. Mass conservation is enforced with upwind/TVD transport.
-It's important to use proper method in checking the volume conservation. In particular, you should make use of the flag consv_check in param.in, instead of calculating flows using the outputs yourself. This is because the velocity outputs have interpolated from side centers to nodes. Strictly speaking, checking volume conservation in SCHISM entails a calculation of semi-implicit fluxes to be consistent with the original formulation but this has not been done in the web version.
+It's important to use proper method in checking the volume conservation. In particular, you should make use of the flag consv_check in param.in, instead of calculating flows using the outputs yourself. This is because the velocity outputs have interpolated from side centers to nodes. Strictly speaking, checking volume conservation in SCHISM entails a calculation of semi-implicit fluxes to be consistent with the original formulation (see transport solver in the online manual).
 Another thing to be aware of is the boundary condition. For example, the imposed river flow is conserved downstream, but if you also impose the elevation b.c., this is not the case anymore. The elev. b.c. as an essential b.c. over-rules the flow b.c. (a Neumann b.c.).

@@ Line 1: / Line 1: @@
-Volume conservation is not enforced in SELFE but the error is generally small. Mass conservation is enforced with upwind/TVD transport.
+Volume conservation is not enforced in SCHISM but the error is generally small. Mass conservation is enforced with upwind/TVD transport.
-It's important to use proper method in checking the volume conservation. In particular, you should make use of the flag consv_check in param.in, instead of calculating flows using the outputs yourself. This is because the velocity outputs have interpolated from side centers to nodes. Strictly speaking, checking volume conservation in SELFE entails a calculation of semi-implicit fluxes to be consistent with the original formulation but this has not been done in the web version.
+It's important to use proper method in checking the volume conservation. In particular, you should make use of the flag consv_check in param.in, instead of calculating flows using the outputs yourself. This is because the velocity outputs have interpolated from side centers to nodes. Strictly speaking, checking volume conservation in SCHISM entails a calculation of semi-implicit fluxes to be consistent with the original formulation but this has not been done in the web version.
 Another thing to be aware of is the boundary condition. For example, the imposed river flow is conserved downstream, but if you also impose the elevation b.c., this is not the case anymore. The elev. b.c. as an essential b.c. over-rules the flow b.c. (a Neumann b.c.).