How to bring bar and \sim symbol at the same level
By all means replace \overset{\sim}{u}
with \tilde{u}
. Optionally, replace \overline{\rho}
with \bar{\rho}
.
Here's a screenshot of u
with various math-mode adornments.
\documentclass{article}
\usepackage{amsmath}
\begin{document}
$\bar{u} \tilde{u} \hat{u} \dot{u} \ddot{u} \acute{u} \grave{u} \check{u} \breve{u}$
$\bar{\bar{u}} \tilde{\tilde{u}} \hat{\hat{u}} \hat{\tilde{u}} \tilde{\bar{u}}$
\end{document}
I have used accents
package to put correctly (using the negative space \kern-.2em
) the \sim
symbol over the u_i
. See the command \accentset{\kern-.2em\sim}{u_i}
.
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath}
\usepackage{accents}
\begin{document}
\begin{equation}
\frac{\partial \bar{\rho}}{\partial{t}}+\frac{\partial (\bar{\rho}\accentset{\kern-.2em\sim}{u_i})}
{\partial{t}}
\end{equation}
\end{document}
Or you can use the "natural" code without the negative space:
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath}
\usepackage{accents}
\begin{document}
\begin{equation}
\frac{\partial \bar{\rho}}{\partial{t}}+\frac{\partial (\bar{\rho}\accentset{\sim}{u_i})}
{\partial{t}}
\end{equation}
\end{document}
This addition is due to the comment of the very good user @egreg that you can see below: Following his advice putting
\accentset{\sim}{u}_i
you will have:
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath}
\usepackage{accents}
\begin{document}
\begin{equation}
\frac{\partial \bar{\rho}}{\partial{t}}+\frac{\partial (\bar{\rho}\accentset{\sim}{u}_i)}
{\partial{t}}
\end{equation}
\end{document}
Just from comment by the user @barbara beeton into chat I use also the \widetilde command: here there is the output.
\documentclass[a4paper,12pt]{article}
\usepackage{mathtools}
\usepackage{amssymb}
\begin{document}
\begin{equation}
\frac{\partial \bar{\rho}}{\partial{t}}+\frac{\partial (\bar{\rho}{\widetilde u}_i)}
{\partial{t}}
\end{equation}
\end{document}