Step 1: Souece replacement by domestic mirrors for fast download speed:(Only needed for Chinese users)
$ cd /etc/apt $ cp sources.list sources.list.bak $ sudo vim sources.list
Change all http://cn.archive.ubuntu.com with http://mirrors.aliyun.com
source sources.list
$ sudo apt-get update && sudo apt-get upgrade
$ sudo apt-get install gcc g++ gfortran make libc6-dev dpkg-dev cmake $ sudo apt-get update $ sudo apt-get install build-essential
$ sudo apt-get install openmpi-bin openmpi-doc libopenmpi-dev
$ sudo sh -c "wget -O - https://dl.openfoam.org/gpg.key | apt-key add -" $ sudo add-apt-repository http://dl.openfoam.org/ubuntu $ sudo apt-add-repository universe $ sudo apt-get update $ sudo apt-get -y install openfoam6