[adelbaew]

We well present, that we have a cube, in his lower fase on the whole planes we start propane, and in from one side fase (from 4 accordingly) we start the air... herewith in verge opposite leaves already mixture of propane and air - what assign it is correct border conditions?

that is to say beside lower fase - an entry of propane, beside lateral fase - an entering the air, on output - a mixture propane - an air..