SQLITE_NOTICE(283): recovered 5 frames from WAL file /data/mtt.fossil-wal
File mttroot/mtt/lib/examples/Thermal/ThermalConduction/HeatedRod/HeatedRod_desc.tex artifact 4a2a8618be part of check-in 1ff989db2f
% Verbal description for system HeatedRod (HeatedRod_desc.tex) % Generated by MTT on Thu Sep 4 18:05:09 BST 1997. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % %% Version control history % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % %% $Id$ % %% $Log$ % %% Revision 1.1 1997/09/11 16:16:50 peterg % %% Initial revision % %% % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{table}[htbp] \begin{center} \leavevmode \begin{tabular}{l l l} \hline Parameter & Symbol & Value \\ \hline Length & $L_r$ & 1m \\ Diameter & $D_r$ & 1mm \\ Resistivity & $\rho$ & $1.68\times10^{-9} \Omega$m \\ Thermal conductivity & $\sigma$ & 390 W$\text{m}^{-1}$\\ Thermal capacity & $\kappa$ & 380 J$\text{m}^{-3}$\\ \hline \end{tabular} \caption{Heated rod parameters} \label{tab:rod} \end{center} \end{table} System \textbf{HeatedRod} is a model of a well-insulated rod of copper with an electric current passing through it which warms it up. The two ends of the rod are fixed at ambient temperature; this is where all the heat loss occurs. This example introduces the idea of the {\bf FP}, \textbf{RT} and \textbf{CT} components in the context of thermal conduction. The model is similar to that described in chapter 8 of \citeN{Cel91}. However, instead of representing the thermal resistance by {\bf RS} components and reinserting the entropy flow, the {\bf RT} component uses two {\bf FP} components to convert from true to pseudo bonds and back again. Similary, the thermal capacity is modelled by the {\bf CT} component. This distributed system (which strictly speaking has a partial differential equation model) is approximated by an ordinary diffferential equation model by modelling the system by a number of discrete segments of length $\Delta x$. Each segment model consists of two conceptual parts. \begin{itemize} \item An ideal lump of copper with no thermal resistance but with the normal attributes of electrical resistance (modelled by the \textbf{RS} component and thermal capacity (modelled by the \textbf{CF} component). \item A thin lump wtih thermal resistance but no thermal capacity or electrical resistance (modeled by the \textbf{RT} component). \end{itemize} At this level of the hierarchy, all bonds are true energy bonds and thus energy conservation is assured. Note that the \textbf{RS} component correctely transforms electrical to thermal energy. The system was simulated with a total of nine lumps whilst passing a current of 1A though the rod for a total of 10s. The initial temperature and the end temperatures were all set at 300K.