Table of unit conversions: Difference between revisions
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To convert the value of a dimensionless variable in 'code' units to 'lab' units, multiply by $C$ from the following table | |||
('code' units are based on $R$ and $U_{cl}$, 'lab' units are based on $D$ and $U_b$). | |||
$variable~\mbox{( | |||
$variable~\mbox{(`lab' units)} = C \times variable ~\mbox{(`code' units)}$, | |||
e.g. $5 \,(D) = C \times 10 \,(R)$ with $C=\frac{1}{2}$. | |||
Revision as of 07:11, 2 June 2017
$ \renewcommand{\vec}[1]{ {\bf #1} } \newcommand{\bnabla}{ \vec{\nabla} } \newcommand{\Rey}{Re} \def\vechat#1{ \hat{ \vec{#1} } } \def\mat#1{#1} $
To convert the value of a dimensionless variable in 'code' units to 'lab' units, multiply by $C$ from the following table ('code' units are based on $R$ and $U_{cl}$, 'lab' units are based on $D$ and $U_b$).
$variable~\mbox{(`lab' units)} = C \times variable ~\mbox{(`code' units)}$,
e.g. $5 \,(D) = C \times 10 \,(R)$ with $C=\frac{1}{2}$.
$\begin{array}{ccccl}
variable & \mbox{'code' units} & \mbox{'lab' units} & \mbox{conversion factor}~C & \mbox{comment}\\
\hline
r,z & R & D & \frac{1}{2} & \mbox{length}\\
\vec{u} & U_{cl} & U_b & 2 & \mbox{speed} \\
t & R/U_{cl} & D/U_b & \frac{1}{4} & \mbox{time} \\
\sigma & U_{cl}/R & U_b/D & 4 & \mbox{growth rate} \\
E & \rho\,U_{cl}^2\, R^3 & \rho\,U_b^2\,D^3 & \frac{1}{2} & \mbox{kinetic energy} \\
D & \rho\,U_{cl}^3\, R^2 & \rho\,U_b^3\,D^2 & 2 & \mbox{dissipation rate} \\
E' & \rho\,U_{cl}^2\, R^2 & \rho\,U_b^2\,D^2 & 1 & \mbox{energy per unit length} \\
\tilde{E} & \rho\,U_{cl}^2 & \rho\,U_b^2 & 4 & \mbox{energy density}
\end{array}$