page break in eqnarray enviroment

Question

I am going to write my thesis by including the List of symbols which are more than a page. I have written it as

\begin{center}
\begin{eqnarray*}
\mbox{A} & - & \mbox{ Area of fin's surface ($m^2$)}\\
\mbox{h} &-& \mbox{Convection heat transfer coefficient $(W/m^2\, K)$}\\
\mbox{P} & - & \mbox{fins perimeter $(m)$}\\
\mbox{W} & - & \mbox{width of the fin $(m)$}\\
\mbox{U} & - & \mbox{Speed of moving fin $ (m/s)$}\\
\mbox{N} & - & \mbox{Dimensionless convection parameter}\\
\mbox{x} & - & \text{Direction along x-axis $(m)$  }\\
\mbox{X} & - & \mbox{Dimensionless coordinate}\\
\mbox{g} &-& \mbox{Gravitational acceleration $(m/s^{2})$}\\
\mbox{L} & - & \mbox{Fins length $(m)$}\\
\mbox{k} & - & \mbox{Porous fins permeability $(m^2)$}\\
\mbox{q} & - & \mbox{Internal heat generation $(W)$}\\
\mbox{Q} & - & \mbox{ Dimensionless internal heatgeneration parameter}\\
\mbox{T} & - & \mbox{ Temperature}\\
\mbox{$\dot{m}$ } & - & \mbox{Mass flow rate $(kg/s)$}\\
\mbox{$R_{a}$} & - & \text{Rayleigh number $\Big(g\,\beta\,t^3\,(T_{b}-T_{a})/\lambda\,\nu\Big)$  }\\
\mbox{$N_{r}$} & - & \text{Dimensionless convection-conduction number }\\
\mbox{$k_{eff}$} & - & \text{Effective thermal conductivity  $(W/m\,K)$ }\\
\mbox{$k_{f}$} & - & \text{ Air thermal conductivity  $(W/m\,K)$  }\\
\mbox{$k_{s}$} & - & \text{Solid thermal conductivity  $(W/m\,K)$   }\\
\mbox{$k_{r}$} & - & \text{Ratio of thermal conductivity $(k_{eff}/k_{s})$  }\\
\mbox{$T_{a}$} & - & \text{Ambient temperature $(K)$ }\\
\mbox{$T_{b}$} & - & \text{Base temperature  $(K)$ }\\
\mbox{$T_{s}$} & - & \text{ Surface temperature  $(K)$  }\\
\mbox{$S_{g}$} & - & \text{Porosity parameter }\\
\mbox{$C_{p}$} & - & \text{Specific heat of the material $(J/kg K)$ }\\
\mbox{$D_{a}$} & - & \text{Darcy number $(K/t^2)$  }\\
\mbox{$T_{s}$} & - & \text{ Surface temperature  $(K)$  }\\
\mbox{$k_{s}$} & - & \text{Solid thermal conductivity  $(W/m\,K)$   }\\
\mbox{$k_{r}$} & - & \text{Ratio of thermal conductivity $(k_{eff}/k_{s})$  }\\
\Gamma & - & \text{Gamma function}\\
\aleph & - & \text{Normalization function}\\
\alpha &-& \mbox{fin shape paramater}\\
\mbox{\ensuremath{\ell}} & - & \mbox{Fractional order}\\
\oplus & - & \mbox{Fuzzy addition}\\
\ominus & - & \mbox{Fuzzy subtraction}\\
\ominus^{gH} & - & \mbox{Generalized Hukuhara difference}\\
\odot & - & \text{Fuzzy multiplication}\\
\mathcal{L} & - & \mbox{Laplace transform}\\
\tilde{\mathcal{E}} & - & \mbox{Fuzzy function}\\
\tilde{j} & - & \mbox{Fuzzy number}\\
\Gamma & - & \text{Gamma function}\\
\aleph & - & \text{Normalization function}
\end{eqnarray*}
\par\end{center}

I want to show it on multiple pages. How can I do it?

Answer 1

You should never use eqnarray, see eqnarray vs align. But even if you like it, it is useless in the present case, because it cannot be split across pages. The reason is that eqnarray ends up creating the following structure, in terms of primitive commands:

$$
\halign to \displaywidth{...}
$$

This is unbreakable no matter what.

For your application, now that we know that eqnarray isn't useful, you can think to a tabular, but this suffers from the same problem. However, there is longtable that allows tabular material to be broken across pages.

Here the first column is in math mode with right alignment

>{$}r<{$}<

and preceded by @{} to remove the initial padding. It is followed by \quad--\quad (change the separator to your liking) and then by the description column, left aligned. Same @{} at the end to remove padding.

By default, longtables are horizontally centered, but acting on \LTleft and making it zero will print the table aligned with the left margin.

\documentclass{book}
\usepackage{longtable}
\usepackage{array}
\usepackage{siunitx}
\sisetup{per-mode=symbol}
\begin{document}
\chapter*{List of symbols}
\begingroup
\setlength{\LTleft}{0pt}
\begin{longtable}{ @{} >{$}r<{$} @{\quad--\quad} l @{} }
A & Area of fin's surface (\si{\square\meter}) \
h & Convection heat transfer coefficient (\si{\watt\per\square\meter\per\kelvin}) \
P & fins perimeter (\si{\meter}) \
W & width of the fin (\si{\meter}) \
U & Speed of moving fin (\si{\meter\per\second}) \
N & Dimensionless convection parameter \
x & Direction along x-axis (\si{\meter})   \
X & Dimensionless coordinate \
g & Gravitational acceleration (\si{\meter\per\square\second}) \
L & Fins length (\si{\meter}) \
k & Porous fins permeability (\si{\square\meter}) \
q & Internal heat generation (\si{\watt}) \
Q & Dimensionless internal heatgeneration parameter \
T & Temperature \
\dot{m} & Mass flow rate (\si{\kilo\gram\per\second}) \
R_{a} & Rayleigh number $\bigl(g\beta t^3(T_{b}-T_{a})/\lambda\nu\bigr)$   \
N_{r} & Dimensionless convection-conduction number  \
k_{\mathrm{eff}} & Effective thermal conductivity  (\si{\watt\per\meter\per\kelvin})  \
k_{f} & Air thermal conductivity  (\si{\watt\per\meter\per\kelvin})   \
k_{s} & Solid thermal conductivity  (\si{\watt\per\meter\per\kelvin})    \
k_{r} & Ratio of thermal conductivity $(k_{\mathrm{eff}}/k_{s})$   \
T_{a} & Ambient temperature (\si{\kelvin})  \
T_{b} & Base temperature  (\si{\kelvin})  \
T_{s} & Surface temperature  (\si{\kelvin})   \
S_{g} & Porosity parameter  \
C_{p} & Specific heat of the material (\si{\joule\per\kilo\gram\per\kelvin})  \
D_{a} & Darcy number ($K/t^2$)   \
T_{s} & Surface temperature  (\si{\kelvin})   \
k_{s} & Solid thermal conductivity  (\si{\watt\per\meter\per\kelvin}) \
k_{r} & Ratio of thermal conductivity $(k_{\mathrm{eff}}/k_{s})$ \
\Gamma & Gamma function \
\aleph & Normalization function \
\alpha & fin shape paramater \
\ell & Fractional order \
\oplus & Fuzzy addition \
\ominus & Fuzzy subtraction \
\ominus^{\mathit{gH}} & Generalized Hukuhara difference \
\odot & Fuzzy multiplication \
\mathcal{L} & Laplace transform \
\tilde{\mathcal{E}} & Fuzzy function \
\tilde{j} & Fuzzy number \
\Gamma & Gamma function \
\aleph & Normalization function
\end{longtable}
\endgroup
\end{document}

I've changed all the units to comply with SI guidelines (the units should be typeset upright).