Difference between revisions of "SSW BBL"
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==Wave-orbital calculations== | ==Wave-orbital calculations== | ||
<wikitex>Near-bed wave-orbital characteristics, including representative orbital velocity $u_{br}$, representative period $T_r$, and average direction of wave propagation $\theta_w$ (degrees, nautical convention, which is positive clockwise from north) are defined according to Madsen (1994). When SWAN results are used, these correspond to UBOT, PWAVE, and DWAVE. If surface-wave statistics (e.g., $H_s$, $T_d$, and $\theta_w$) are | <wikitex>Near-bed wave-orbital characteristics, including representative orbital velocity $u_{br}$, representative period $T_r$, and average direction of wave propagation $\theta_w$ (degrees, nautical convention, which is positive clockwise from north) are defined according to Madsen (1994). When SWAN results are used, these correspond to UBOT, PWAVE, and DWAVE. If surface-wave statistics (e.g., $H_s$, $T_d$, and $\theta_w$) are provided, they can be converted to bottom orbital velocity externally (using, for example, the routines suggested in [[Bibliography#WibergP_2008a | Wiberg and Sherwood (2008)]] and provided as UBOT in a SWAN input file. Alternatively, if SSW_CALC_UB is defined, orbital velocity $u_{br}$ is calculated according to linear wave theory as follows: | ||
$$ | $$ | ||
u_{br} = \frac{H_s}{2\sinh (kh)} | u_{br} = \frac{H_s}{2\sinh (kh)} | ||
$$ | $$ | ||
where $kh$ is [[SoulsbyKH | | where $kh$ is wavenumber x depth, and $k$ can be approximated using one of the methods described [[SoulsbyKH | here]].</wikitex> | ||
</wikitex> | |||
==Ripple Geometry== | ==Ripple Geometry== | ||
Revision as of 19:20, 3 November 2008
class="title">SSW bottom boundary layer formulation
Wave-orbital calculations
<wikitex>Near-bed wave-orbital characteristics, including representative orbital velocity $u_{br}$, representative period $T_r$, and average direction of wave propagation $\theta_w$ (degrees, nautical convention, which is positive clockwise from north) are defined according to Madsen (1994). When SWAN results are used, these correspond to UBOT, PWAVE, and DWAVE. If surface-wave statistics (e.g., $H_s$, $T_d$, and $\theta_w$) are provided, they can be converted to bottom orbital velocity externally (using, for example, the routines suggested in Wiberg and Sherwood (2008) and provided as UBOT in a SWAN input file. Alternatively, if SSW_CALC_UB is defined, orbital velocity $u_{br}$ is calculated according to linear wave theory as follows: $$ u_{br} = \frac{H_s}{2\sinh (kh)} $$ where $kh$ is wavenumber x depth, and $k$ can be approximated using one of the methods described here.</wikitex>
Ripple Geometry
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Bottom Roughness
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Wave-current combined stress and roughness
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Skin friction - form drag partitioning
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Maximum shear stress
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