云極（EPC）是UCloud提供的高性能計算產品，為用戶提供基于公有云技術的超高性能算力以及涵蓋數據傳輸、數據計算、數據可視化等一站式的使用體驗。

EPC支持以下功能：

 -秒級創建計算節點，按需計費，關機不收費

-支持開箱即用的應用鏡像

-贈送1000GB共享存儲，支持FTP文件上傳和下載功能，帶寬最高可達100Mb

-可掛載虛擬的Nvidia Tesla T4 GPU, 為圖形處理功能加速

-支持8- 240核多種規格計算節點

 本文將演示基于CentOS-7.6 x86_64位系統部署OpenFOAM。

 一、開通UCloud云服務

 流程：注冊-登錄-實名。UCloud注冊鏈接：https://passport.ucloud.cn/#login

二、創建算力資源

 1、 登錄并前往控制臺頁面，選擇【云極高性能計算EPC】

2、 點擊【創建計算節點】，進入主機配置信息頁面

3、 選擇鏡像、CPU及內存

 -鏡像：支持標準鏡像，自定義鏡像以及部分高性能應用鏡像

-配置：點擊卡片即可

-網絡增強：Nvidia Tesla T4, 顯存4GB，如需云上處理，可開啟，目前僅支持Windows系統（增值服務）

-存儲：默認1000GB

-網絡：外網帶寬默認5Mb（免費）

三、遠程登錄節點

 可使用PuTTY登錄（注意，該模式登錄后是命令行界面），輸入云主機的公網IP即可SSH登錄；CentOS系統賬號是root，密碼是在購買云主機時設置的密碼；

四、部署OpenFOAM

 1、安裝OpenFOAM依賴

# yum install -y autoconf automake gcc glibc gcc-c++ gcc-gfortran git libgcc libstdc++ cmake bison flex patch
# yum install -y boost-devel gmp-devel gstreamer-plugins-base-devel libXi-devel libXinerama-devel libXrandr-devel libXrender-devel \
libXt-devel mpfr-devel ncurses-devel python-devel qt-devel readline-devel zlib-devel

 2、下載OpenFOAM并解壓

# mkdir -p /data/OpenFOAM
# cd /data/OpenFOAM
# wget -c https://sourceforge.net/projects/openfoam/files/v2006/OpenFOAM-v2006.tgz?use_mirror=nchc -O OpenFOAM-v2006.tgz# wget -c https://sourceforge.net/projects/openfoam/files/v2006/ThirdParty-v2006.tgz?use_mirror=nchc -O ThirdParty-v2006.tgz# tar zxvf OpenFOAM-v2006.tgz
# tar zxvf ThirdParty-v2006.tgz

3、修改安裝路徑和其他編譯環境

# sed -i 's/$HOME/\/data/g' OpenFOAM-v2006/etc/bashrc

修改其他細節

# sed -i 's#\(default_gcc_version=\)gcc-4.8.5#\1gcc-7.2.0#' OpenFOAM-v2006/etc/config.sh/compiler
# sed -i 's#gmp-system#gmp-6.1.2#' OpenFOAM-v2006/etc/config.sh/compiler
# sed -i 's#mpfr-system#mpfr-4.0.1#' OpenFOAM-v2006/etc/config.sh/compiler
# sed -i 's#mpc-system#mpc-1.1.0#' OpenFOAM-v2006/etc/config.sh/compiler
# sed -i 's#\(cmake_version=\)cmake-system#\1cmake-3.12.4#' OpenFOAM-v2006/etc/config.sh/cmake
# sed -i 's=\(^unset WM_ARCH_OPTION\)=#\1=' OpenFOAM-v2006/etc/config.sh/settings

加載OpenFOAM環境變量

# source /data/OpenFOAM/OpenFOAM-v2006/etc/bashrc WM_COMPILER_TYPE=ThirdParty WM_COMPILER=Gcc72 WM_MPLIB=OPENMPI WM_ARCH_OPTION=64# echo "alias of2006='source /data/OpenFOAM/OpenFOAM-v2006/etc/bashrc $FOAM_SETTINGS'" >> $HOME/.bashrc

使用別名來管理多OpenFOAM版本

# of2006

加載環境變量時，可能會看到如下消息，需求編譯Gcc版本

Warning in /data/OpenFOAM/OpenFOAM-v2006/etc/config.sh/settings:
Cannot find 'Gcc72' compiler installation
/data/OpenFOAM/ThirdParty-v2006/platforms/linux64/gcc-7.2.0Either install this compiler version, or use the system compiler by setting
WM_COMPILER_TYPE to 'system' in $WM_PROJECT_DIR/etc/bashrc.

4、獲取編譯GCC和binutils的腳本

# cd $WM_THIRD_PARTY_DIR
# wget https://raw.githubusercontent.com/wyldckat/scripts4OpenFOAM3rdParty/master/getGcc# wget https://raw.github.com/wyldckat/ThirdParty-2.0.x/binutils/getBinutils# wget https://raw.github.com/wyldckat/ThirdParty-2.0.x/binutils/makeBinutils# chmod +x get* make*

編譯Gcc 7.2.0

# sed -i 's#gccPACKAGE.tar.bz2#gccPACKAGE.tar.gz#' getGcc
# ./getGcc gcc-7.2.0 gmp-6.1.2 mpfr-4.0.1 mpc-1.1.0# ./makeGcc
# wmRefresh

編譯GNU Binutils

# sed -i 's/binutils-2.23/binutils-2.31.1/g' getBinutils
# sed -i 's/binutils-2.23/binutils-2.31.1/g' makeBinutils
# ./getBinutils
# ./makeBinutils gcc-7.2.0

5、編譯Cmake

ParaView 5.6.0需要較新的CMake3.0以上版本，而CGAL也需要CMake；

# cd $WM_THIRD_PARTY_DIR
# wget https://raw.github.com/wyldckat/scripts4OpenFOAM3rdParty/master/getCmake# chmod +x getCmake
# sed -i -e 's#2.8#3.12#' -e 's#version}.3#version}.4#' getCmake
# ./getCmake
# ./makeCmake cmake-3.12.4 > log.makeCM 2>&1# wmRefresh

6、編譯THIRD_PARTY

# cd $WM_THIRD_PARTY_DIR
# ./Allwmake -j 
# wmRefresh

7、編譯OpenFOAM

# foamSystemCheck
# cd $WM_PROJECT_DIR
# ./Allwmake -j

8、編譯QT

# cd $WM_THIRD_PARTY_DIR
# wget https://github.com/wyldckat/scripts4OpenFOAM3rdParty/raw/master/getQt# sed -i -e 's=4.6=5.9=' -e 's=5.9.4=5.9.6=' -e 's=tar -xzf=tar -Jxvf=' getQt
# sed -i -e 's=tar.gz=tar.xz=' -e 's=$major/$tarFile=$major/$version/single/$tarFile=' getQt
# chmod +x getQt
# ./getQt
# ./makeQt qt-5.9.6 > log.mkqt

9、編譯ParaView 5.6.0

# cd $WM_THIRD_PARTY_DIR
# ./makeParaView -qt-5.9 -mpi -python -python-lib /path/lib64/libpython2.7.so -python-include /path/include/python2.7

10、測試motor流場算例

# wget http://hpc.cn-sh2.ufileos.com/hpc_case/motorBike_v2006.tar.gz# tar zxvf motorBike_v2006.tar.gz
# cd motorBike_v2006
# surfaceFeatureExtract
# blockMesh
# decomposePar -copyZero
# mpirun -np 32 snappyHexMesh -parallel -overwrite
# mpirun -np 32 patchSummary -parallel
# mpirun -np 32 potentialFoam -parallel
# mpirun -np 32 simpleFoam -parallel

備注：

如果需要修改計算的CPU數量，修改算例中decomposeParDict文件的numberOfSubdomains參數，這個等于CPU核數；

五、限時領取免費算力

 1、UCloud 云極高性能計算EPC限時特惠，新客注冊贈送1000核時免費集群算力

             http://specialneedsforspecialkids.com/site/active/epc.html

 2、更有EPC校園大使活動，成功邀請高校用戶或科研機構使用我們的產品即可獲得現金獎勵，期待你來!

 3、如有任何問題，可在此留言或加入UCloud-HPC高校科研交流群溝通 ?