When an initially quiescent, horizontal fluid layer is heated uniformly from below, the critical time of the onset of natural convection is analysed by employing the propagation theory. For deep-pool systems the basic temperature profile is approximat...
When an initially quiescent, horizontal fluid layer is heated uniformly from below, the critical time of the onset of natural convection is analysed by employing the propagation theory. For deep-pool systems the basic temperature profile is approximated by using the integral method and a new stability equation is generated. The critical conditions are found to have following relation: τ_c = 4.57 Ra^(-½) for Pr →∞ This relation agrees well with experimental data in the range of Ra >10⁴. Also, it is seen that the initiated convection is amplified to observable magnitude at the time 4 τ_c.