freefoam-rhoPorousSimple: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/freefoam-rhoPorousSimple - from package: freefoam

You may install the required package with command apt-get install {package}

Error in other languages:
freefoam-rhoPorousSimple: bevel nie gevind nie
freefoam-rhoPorousSimple: comandă negăsită
freefoam-rhoPorousSimple: comando não encontrado
freefoam-rhoPorousSimple: commande introuvable
freefoam-rhoPorousSimple: command not found
freefoam-rhoPorousSimple: käsku ei ole
freefoam-rhoPorousSimple: không tìm thấy lệnh
freefoam-rhoPorousSimple: komanda nerasta
freefoam-rhoPorousSimple: Kommando nicht gefunden.
freefoam-rhoPorousSimple: kommandot finns inte
freefoam-rhoPorousSimple: komut yok
freefoam-rhoPorousSimple: nie znaleziono polecenia
freefoam-rhoPorousSimple: níor aimsíodh an t-ordú
freefoam-rhoPorousSimple: no se encontró la orden
freefoam-rhoPorousSimple: no s'ha trobat l'ordre
freefoam-rhoPorousSimple: opdracht niet gevonden
freefoam-rhoPorousSimple: parancs nem található
freefoam-rhoPorousSimple: perintah tidak ditemukan
freefoam-rhoPorousSimple: príkaz nenájdený
freefoam-rhoPorousSimple: příkaz nenalezen
freefoam-rhoPorousSimple: команда не найдена
freefoam-rhoPorousSimple: командата не е открита
freefoam-rhoPorousSimple: 命令找不到
freefoam-rhoPorousSimple: コマンドが見つかりません