diff --git a/documentation/gaia/user/latex/3_1-SedimentTransportProcessesBedAndStratigraphy_bedload.tex b/documentation/gaia/user/latex/3_1-SedimentTransportProcessesBedAndStratigraphy_bedload.tex index f6b631fbcfcfed85df3b7648e7677c90db8436cb..08d16e9a126e0617ea14dcb513833dd943b1fcec 100644 --- a/documentation/gaia/user/latex/3_1-SedimentTransportProcessesBedAndStratigraphy_bedload.tex +++ b/documentation/gaia/user/latex/3_1-SedimentTransportProcessesBedAndStratigraphy_bedload.tex @@ -16,9 +16,9 @@ Above, $Q_b$ is the bedload transport rate per unit width, computed as a functio As presented and discussed in \S~\ref{sec:bedevol}, \gaia{} solves the Exner equation as a function of the mass transport flux rate and not in terms of volumetric transport rate, as follows: \begin{equation} -\mathbf Q_{mb}=\rho \mathbf Q_b, +\mathbf Q_{mb}=\rho_s \mathbf Q_b, \end{equation} -where $\mathbf Q_{mb}$ is the vector of mass transport rate per unit width without pores (kg/(m~s)), with $\rho$ the density. +where $\mathbf Q_{mb}$ is the vector of mass transport rate per unit width without pores (kg/(m~s)), with $\rho_s$ the sediment density. %The equation is obtained writing the conservative law equation for sediment and integrating along the vertical, keeping density in the equation: %\begin{align} @@ -115,7 +115,13 @@ f(\theta)=\left\{\begin{array}{ll} \end{array} \right. \end{equation*} -where the non-dimensional diameter $D_*=d[(\rho_s/\rho-1)g/\nu^2]^{1/3}$, with $\nu$ the water viscosity (keyword \telkey{WATER VISCOSITY}, equal to $10^{-6}$ m/s$^2$ by default). +where $D_*=d[(\rho_s/\rho-1)g/\nu^2]^{1/3}$ is the non-dimensional diameter, +with $\rho_s$ the sediment density (keyword \telkey{CLASSES SEDIMENT DENSITY}, equal to +2650~kg/m$^3$ by default), +$\rho$ the water density (keyword \telkey{WATER DENSITY}, equal to 1000~kg/m$^3$ by default in +\telemac{2D} or \telkey{AVERAGE WATER DENSITY}, equal to 1025~kg/m$^3$ by default in +\telemac{3D}), +$\nu$ the water viscosity (keyword \telkey{WATER VISCOSITY}, equal to $10^{-6}$ m/s$^2$ by default). \item Fortran subroutine {\ttfamily bedload\_einst\_gaia.f}. \end{itemize} @@ -324,7 +330,7 @@ where $\theta_{\beta cr}$ is the corrected Shields number for a sloping bed, $\ \medskip \item Apsely and Stansby~\cite{ApsleyStansby2008} which is based on the modification of the critical Shields parameter $\theta_{\beta cr}$ and on the calculation of a effective dimensionless shear stress $\theta_{beta}$. -The modification of the critical shear stress can only be done for threshold bedload formulas. The modification of the Shields parameter $\theta_{\beta}$ could be done for all bedload formulas which are using the shear stress and accordingly the Shields parameter. But it is not recommended. +The modification of the critical shear stress can only be done for threshold bedload formulas. The modification of the Shields parameter $\theta_{\beta}$ could be done for all bedload formulas which are using the shear stress and accordingly the Shields parameter. But it is not recommended. \begin{equation*} \frac{\theta_{\beta cr}}{\theta_{cr}} = \cos\chi = 1 / \sqrt{1 + (\partial z /\partial x)^2 + (\partial z/ \partial y)^2 } \end{equation*} @@ -341,7 +347,7 @@ where $\gamma$ is the direction of the bed shear stress. %------------------------------------------------------------------------------- \subsubsection{Sediment sliding} %------------------------------------------------------------------------------- -If the bottom slope is higher than a critical slope (typically the angle of repose) sediments can be moved due to geomechanical processes. In \gaia{} two formulas are implemented to calculate sediment displacement in down-slope direction only driven by the bottom slope. +If the bottom slope is higher than a critical slope (typically the angle of repose) sediments can be moved due to geomechanical processes. In \gaia{} two formulas are implemented to calculate sediment displacement in down-slope direction only driven by the bottom slope. \begin{itemize} \item The first method is a simple and mass conservative smoothing of the bottom slopes. The changed masses are balanced separately in the mass-balance (MASS EVOLUTION DUE TO SLIDING FORMULA 1). @@ -374,7 +380,7 @@ The correction of the intensity of bedload transport rate can be done by : \begin{itemize} \item the Koch and Flokstra formulation \telkey{FORMULA FOR SLOPE EFFECT} (integer type variable, set to {\ttfamily = 1} by default). This keyword has the associated keyword \telkey{BETA} (real type variable, set to {\ttfamily = 1.30} by default) \item the Soulsby formulation \telkey{FORMULA FOR SLOPE EFFECT = 2}. This keyword has the associated keyword \telkey{FRICTION ANGLE OF THE SEDIMENT} (real type variable, set to {\ttfamily = 40.} by default) and the critical Shields parameter which is calculated by default or can be set with the keyword \telkey{CLASSES SHIELDS PARAMETERS}. -\item the Apsley and Stansby formulation \telkey{FORMULA FOR SLOPE EFFECT = 3}. This keyword has the associated keyword \telkey{FRICTION ANGLE OF THE SEDIMENT} (real type variable, set to {\ttfamily = 40} by default) and the critical Shields parameter which is calculated by default or can be set with the keyword \telkey{CLASSES SHIELDS PARAMETERS}. +\item the Apsley and Stansby formulation \telkey{FORMULA FOR SLOPE EFFECT = 3}. This keyword has the associated keyword \telkey{FRICTION ANGLE OF THE SEDIMENT} (real type variable, set to {\ttfamily = 40} by default) and the critical Shields parameter which is calculated by default or can be set with the keyword \telkey{CLASSES SHIELDS PARAMETERS}. \end{itemize} %------------------------------------------------------------------------------- @@ -385,10 +391,10 @@ The keyword \telkey{SECONDARY CURRENTS} (logical type variable, set to {\ttfamil %------------------------------------------------------------------------------- \subsubsection{Correction due to sediment sliding} %------------------------------------------------------------------------------- -Sediment sliding will be taken into account if the keyword \telkey{SEDIMENT SLIDE} +Sediment sliding will be taken into account if the keyword \telkey{SEDIMENT SLIDE} (integer type variable, set to {\ttfamily = 0} by default) is higher zero: \begin{itemize} -\item \telkey{SEDIMENT SLIDE = 1} smoothes the bottom slopes up to the angle of repose. +\item \telkey{SEDIMENT SLIDE = 1} smoothes the bottom slopes up to the angle of repose. \item \telkey{SEDIMENT SLIDE = 2} calculates the sediment sliding with the avalanching formula from Apsley and Stansby. \end{itemize} This keyword has the associated keyword \telkey{FRICTION ANGLE OF THE SEDIMENT} (real type variable, set to {\ttfamily = 40} by default) diff --git a/documentation/gaia/user/latex/HowTos.tex b/documentation/gaia/user/latex/HowTos.tex index fe905bc633ff2abf1e1c979570e8717142625ca7..66b50bf2f15460ed45c7866a24e419faa30b5410 100644 --- a/documentation/gaia/user/latex/HowTos.tex +++ b/documentation/gaia/user/latex/HowTos.tex @@ -90,7 +90,7 @@ MASS-BALANCE = YES \begin{itemize} \item Sediment diameters, defined by the keyword \telkey{CLASSES SEDIMENT DIAMETERS} (real list, {\ttfamily = 0.01} m by default) \item Sediment density, defined by the keyword \telkey{CLASSES SEDIMENT DENSITY} (real type, {\ttfamily = 2650.0} kg$/$m$^3$ by default) -\item Shields parameter $\tau_c$ [N\,m$^{-2}$], defined by the keyword \telkey{CLASSES SHIELDS PARAMETERS} (real list, = -9 by default). If it is not known, it is necessary to give a negative value to let \gaia{} compute it as a function of the non-dimensional grain diameter $D_*=d_{50}[(\rho_s/\rho-1)g/\nu^2]^{1/3}$ in the subroutine \texttt{shields.f}: +\item Critical Shields parameter, $\theta_{cr}$ ($-$), defined by the keyword \telkey{CLASSES SHIELDS PARAMETERS} (real list, = -9 by default). If it is not known, it is necessary to give a negative value to let \gaia{} compute it as a function of the non-dimensional grain diameter $D_*=d_{50}[(\rho_s/\rho-1)g/\nu^2]^{1/3}$ in the subroutine \texttt{shields.f}: \begin{equation*} \frac{\tau_c}{g(\rho_s -\rho)d_{50}}=\left\{\begin{array}{ll} 0.24 D_*^{-1}, & D_* \leq 4 \\ @@ -101,7 +101,8 @@ MASS-BALANCE = YES \end{array} \right. \end{equation*} -with $d_{50}$ the median sand grain diameter (m), $\rho$ the water density $=1000$ kg$/$m$^3$ by default, $\rho_s$ the sediment density $=2650$kg$/$m$^3$ by default, and $\nu$ the kinematic viscosity $=1.0\times 10^{-6}$m$^2$s$^{-1}$ by default. +with $d_{50}$ the median sand grain diameter (m), $\rho$ the water density =1000~kg/m$^3$ by default +in \telemac{2D} and =1025~kg/m$^3$, $\rho_s$ the sediment density =2650~kg/m$^3$ by default, and $\nu$ the kinematic viscosity $=1.0\times 10^{-6}$m$^2$s$^{-1}$ by default. \item Settling velocity, it can be specified by the user or calculated by the model as a function of grain diameter, keyword \telkey{SETTLING VELOCITIES } (real list, =-9 by default). If a negative value is given, \gaia{} will compute it as function of grain diameter (cf. chapter \ref{Chap:Sed:Ex:cohesive}): \begin{equation*} @@ -115,7 +116,7 @@ w_{s} = \left\{\begin{array}{ll} \end{array} \right. \end{equation*} -with $s=\rho_{s}/\rho_0$ is the relative density and $g$ is the acceleration of the gravity.% +with $s=\rho_{s}/\rho$ is the relative density and $g$ is the acceleration of the gravity.% \item Bed porosity, keyword \telkey{LAYERS NON COHESIVE BED POROSITY} (real type, {\ttfamily = 0.40} by default) \end{itemize}