[radiation.boy]

i want to analyze the flow for the case ..when we are given a cube say 10m each side cube..this cube has one inlet at top and one outlet at bottom..it contain air at 2 bar pressure and temperature is 25c and heated air is blown with velocity of 5 m/s and temperature 100 c from top inlet and air comes out through outlet...well the problem is how to give the condition of temperature and pressure of the cube...these were initial condition for the cube after the air is inserted through inlet condition will change ...some one said me during giving boundary condition in gambit use interior and select all faces of cube and when u insert dis file into fluent den give these conditions to interior...but dis still does not work...fluent give me an error while reading interior of the cube.. plz plz try to solve me dis problem ..i will be very thank full to u peoples...

2nd i want to know ..if i ave 2 spearte volume and i av done separte meshing for it and it is required that one fluid enter into another supose a rod is inersted into a cube ...rod is air and say cube is water ..if i try to run this simukation then it consier the interface between the the two fluid as wall and fluent show an error of reversed flow ...i wana know how to give boundary connditions in gambit so that one fluid enter into other and dis interface which is fluent consider is wall is remocved ...plz plz plz solve ma problem ...thnaks in advance