如何增加章节标题和页眉之间的空白？

Question

我想要这样的东西：

我正在使用article文档类和包geometry，但我认为我缺少一些部分的定义。我是这方面的新手，想在这个平台上写我的硕士论文。这是我的代码的一部分，也是我目前所得到的。

    \documentclass[a4paper,11pt,oneside]{article}
% LANGUAGE AND FONTS PREAMBLE
\usepackage[brazilian]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{charter}%document font type
\usepackage[hidelinks]{hyperref}%Allows clickable references
%PAGE AND TITLES FORMATTING
\usepackage[margin=2cm,left=2.5cm]{geometry}
\usepackage{titlesec}
\usepackage{lipsum}% just to generate text for the example
\def\changemargin#1#2{\list{}{\rightmargin#2\leftmargin#1}\item[]}
\let\endchangemargin=\endlist %Allows to change margins in selected particular parts of the text

\titleformat{\section} %Commmands for all titles formatting
  {\Large\sc\bfseries\center}{\thesection}{0.5cm}{}
\begin{document}

\section*{ABSTRACT}\label{sec:abstract}
\addcontentsline{toc}{section}{\numberline{}ABSTRACT}
Abstract do trabalho. Inglês, com keywords.
Work abstract, English with keyboards.

\cleardoublepage
\section{INTRODUÇÃO}\label{sec:intro}
\lipsum[1]
\lipsum[2]
\lipsum[3]
\lipsum[4]
\lipsum[1]
\lipsum[2]
\lipsum[3]
\lipsum[4]
\cleardoublepage

\end{document}