Manning's n at sea floor - Revision history

Wpringle: /* Negative n Values */

2020-04-14T01:08:47Z

Negative n Values

← Older revision		Revision as of 21:08, 13 April 2020
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	== Negative ''n'' Values ==		== Negative ''n'' Values ==
			{{ADC version\|version=55\|relation=ge}}
	If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]] or the spatially varying [[Fort.13_file#Quadratic_Friction_coefficient\|quadratic_friction_coefficient_at_sea_floor]] fort.13 nodal attribute, will be used instead.		If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]] or the spatially varying [[Fort.13_file#Quadratic_Friction_coefficient\|quadratic_friction_coefficient_at_sea_floor]] fort.13 nodal attribute, will be used instead.

Wpringle: /* Negative n Values */

2020-04-14T01:07:54Z

Negative n Values

← Older revision		Revision as of 21:07, 13 April 2020
Line 16:		Line 16:

	== Negative ''n'' Values ==		== Negative ''n'' Values ==
	If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or ~~through~~ the spatially varying [[Fort.13_file#Quadratic_Friction_coefficient\|quadratic_friction_coefficient_at_sea_floor]] fort.13 nodal attribute will be used instead.		If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]] or the spatially varying [[Fort.13_file#Quadratic_Friction_coefficient\|quadratic_friction_coefficient_at_sea_floor]] fort.13 nodal attribute, will be used instead.

	== Specifying ''n'' Values ==		== Specifying ''n'' Values ==

Wpringle: /* Negative n Values */

2020-04-14T01:06:36Z

Negative n Values

← Older revision		Revision as of 21:06, 13 April 2020
Line 16:		Line 16:

	== Negative ''n'' Values ==		== Negative ''n'' Values ==
	If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[quadratic_friction_coefficient_at_sea_floor]] [[fort.13 ~~file]] [[~~nodal attribute]] will be used instead.		If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[Fort.13_file#Quadratic_Friction_coefficient\|quadratic_friction_coefficient_at_sea_floor]] fort.13 nodal attribute will be used instead.

	== Specifying ''n'' Values ==		== Specifying ''n'' Values ==

Wpringle: /* Negative n Values */

2020-04-14T01:05:16Z

Negative n Values

← Older revision		Revision as of 21:05, 13 April 2020
Line 16:		Line 16:

	== Negative ''n'' Values ==		== Negative ''n'' Values ==
	If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''f''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[quadratic_friction_coefficient_at_sea_floor]] [[fort.13 file]] [[nodal attribute]] will be used instead.		If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''d''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[quadratic_friction_coefficient_at_sea_floor]] [[fort.13 file]] [[nodal attribute]] will be used instead.

	== Specifying ''n'' Values ==		== Specifying ''n'' Values ==

Wpringle: /* Attribute Summary */

2020-04-14T01:04:52Z

Attribute Summary

← Older revision		Revision as of 21:04, 13 April 2020
Line 4:		Line 4:
	[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]]		[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]]
	If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:		If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:
	:<math>~~C_f~~(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>		:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>
	where,		where,
	* ''C''<sub>''f''</sub> drag coefficient		* ''C''<sub>''d''</sub> drag coefficient
	* ''t'' time		* ''t'' time
	* ''g'' acceleration due to gravity		* ''g'' acceleration due to gravity

Wpringle: /* Negative n Values */

2020-04-14T01:04:14Z

Negative n Values

← Older revision		Revision as of 21:04, 13 April 2020
Line 16:		Line 16:

	== Negative ''n'' Values ==		== Negative ''n'' Values ==
	If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''f''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[~~quadratic_friction~~]] [[fort.13 file]] [[nodal attribute]] will be used instead.		If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''f''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[quadratic_friction_coefficient_at_sea_floor]] [[fort.13 file]] [[nodal attribute]] will be used instead.

	== Specifying ''n'' Values ==		== Specifying ''n'' Values ==

Wpringle at 01:03, 14 April 2020

2020-04-14T01:03:20Z

← Older revision		Revision as of 21:03, 13 April 2020
Line 4:		Line 4:
	[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]]		[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]]
	If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:		If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:
	:<math>~~C_d~~(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>		:<math>C_f(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>
	where,		where,
	* ''C''<sub>''d''</sub> drag coefficient		* ''C''<sub>''f''</sub> drag coefficient
	* ''t'' time		* ''t'' time
	* ''g'' acceleration due to gravity		* ''g'' acceleration due to gravity
Line 14:		Line 14:
	The addition of the water surface elevation is conditional upon the setting of <code>[[NOLIFA]]</code>: ''η'' is treated as zero if <code>NOLIFA = 0</code> in the [[fort.15]] file. Finally, the value of <code>[[CF]]</code> in the fort.15 is used to set a lower limit on the resulting equivalent quadratic friction coefficient, under the assumption the ''C''<sub>''d''</sub> calculated from this formula tends to become too small in deep water.		The addition of the water surface elevation is conditional upon the setting of <code>[[NOLIFA]]</code>: ''η'' is treated as zero if <code>NOLIFA = 0</code> in the [[fort.15]] file. Finally, the value of <code>[[CF]]</code> in the fort.15 is used to set a lower limit on the resulting equivalent quadratic friction coefficient, under the assumption the ''C''<sub>''d''</sub> calculated from this formula tends to become too small in deep water.
	<br clear=all>		<br clear=all>

			== Negative ''n'' Values ==
			If a combination of Manning's and time invariant [[bottom friction]] is desired, users can elect to set the Manning's [[nodal attribute]] to a negative value at certain mesh nodes. At mesh nodes where ''n'' is negative, the time invariant ''C''<sub>''f''</sub> coefficient, specified via a constant <code>[[CF]]</code> in the [[fort.15 file]], or through the spatially varying [[quadratic_friction]] [[fort.13 file]] [[nodal attribute]] will be used instead.

	== Specifying ''n'' Values ==		== Specifying ''n'' Values ==

Taylorgasher: Removed spurious text.

2019-09-06T15:33:05Z

Removed spurious text.

← Older revision		Revision as of 11:33, 6 September 2019
Line 2:		Line 2:

	== Attribute Summary ==		== Attribute Summary ==
	[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]] ~~contours for Manning's n~~		[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]]
	If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:		If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:
	:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>		:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>

Taylorgasher at 14:03, 20 May 2019

2019-05-20T14:03:24Z

← Older revision		Revision as of 10:03, 20 May 2019
Line 2:		Line 2:

	== Attribute Summary ==		== Attribute Summary ==
	[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient :<math>C_d</math> contours for Manning's n and total depth]] contours for Manning's n		[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient <math>C_d</math> contours for Manning's n and total depth]] contours for Manning's n
	If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:		If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:
	:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>		:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>

Taylorgasher: Added caption

2019-05-20T14:02:45Z

Added caption

← Older revision		Revision as of 10:02, 20 May 2019
Line 2:		Line 2:

	== Attribute Summary ==		== Attribute Summary ==
	[[File:mnasfContours3.png\|400px\|right\|~~border~~]]		[[File:mnasfContours3.png\|400px\|right\|thumb\|Drag coefficient :<math>C_d</math> contours for Manning's n and total depth]] contours for Manning's n
	If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:		If the user elects to use this nodal attribute, which ADCIRC reads in as the <code>[[ManningsN]]</code> variable, <code>[[NOLIBF]]</code> must be set to 1 or the run will terminate. During execution, the Manning’s n values specified are converted to equivalent quadratic friction coefficients before the bottom stress is calculated. The equivalent quadratic friction coefficient is calculated according to the following formula at each node at each time step:
	:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>		:<math>C_d(t)=\frac{gn^2}{\sqrt[3]{h+\eta(t)}}</math>