% arara: lualatex: { options: [ '-synctex=1', '-shell-escape' ]}
% arara: makeglossaries
% arara: lualatex: { options: [ '-synctex=1', '-shell-escape' ]}

\documentclass{elsarticle}
\usepackage{booktabs}
\usepackage{calc,siunitx}
\sisetup{load-configurations = abbreviations}
\usepackage[xindy,automake,stylemods,nonumberlist]{glossaries-extra}

\makeglossaries

\newlength\glsnamewidth
\newlength\glsunitwidth
\settowidth{\glsnamewidth}{\textbf{sign}}
\settowidth{\glsunitwidth}{\textbf{unit}}

\newglossarystyle{nameunitdesc}{%
    \setlength{\glsdescwidth}{\linewidth-\glsnamewidth-\glsunitwidth-6\tabcolsep}%
    \renewenvironment{theglossary}%
    {\begin{supertabular}{@{}p{\glsnamewidth}p{\glsunitwidth}p{\glsdescwidth}@{}}\toprule\addlinespace[5pt]}%
        {\bottomrule\end{supertabular}}%
    \renewcommand*{\glossaryheader}{}%
    \renewcommand*{\glsgroupheading}[1]{}%
    \renewcommand{\glossentry}[2]{%
        \raggedright\glstarget{##1}{\glossentryname{##1}} &
        \centering\glossentrysymbol{##1} &
        \glossentrydesc{##1}\tabularnewline
    }%
    \renewcommand{\subglossentry}[3]{\glossentry{##2}{##3}}%
    \renewcommand*{\glsgroupskip}{}%
}

\glsnoexpandfields

\newglossaryentry{L}{name={L},description={some text},symbol={---}}
\newglossaryentry{Cp}{name={Cp},description={specific heat}, symbol={[\si{\J\per\kg\per\K}]}}
\newglossaryentry{Gamma_l}{name={$\Gamma_l$},description={Laser-irradiated boundary}}
\newglossaryentry{Delta}{name={$\Delta$},description={Nodal spacing},symbol={[\si{\um}]}}


\journal{Applied Mathematics and Computation}

\glsaddall

\begin{document}


    \section{Introduction}


    \glsFindWidestUsedAnyNameSymbol{\glsunitwidth}
    \settowidth{\dimen0}{\glsgetwidestname}
    \ifdim\dimen0>\glsnamewidth
    \glsnamewidth=\dimen0
    \fi

    \printglossary[style=nameunitdesc,title=Nomenclature]


\end{document}