Numerical simulations results by Singh and Srinivasan[1] show concentration fields at different Rayleigh numbers for fixed value of Rρ  = 6.  The parameters are: (a) RaT  = 7×108 , t=1.12×10−2, (b) RaT  =3.5×108, t=1.12×10−2, (c) RaT =7×106, t=1.31×10−2, (d) RaT=7×105, t=3.69×10−2. It is seen from the figure that finger characteristics such as width, evolution pattern are a function of Rayleigh numbers.