Heat transfer/ Temperature calculation

Novice

hi all,

I have to calculate the temperature distribution inside a clossed vessel(cylinder) with some Quartz glass rods inside the cyllinder. The cylinder consistes of water(99% water and 1% air). Quartz rods are operated at different temperatures(the end points are operated at different temp to that of the middle).

Can anybody please let me know how can i sep up the case. And what should be the timestep size and howmany number of time step should i consider.

Thanks in advance