Mathematical modelling of the stability characteristics of a natural circulation loop

The natural circulation phenomenon in a rectangular loop has been mathematically simulated and its stability characteristics have been investigated. The conservation equations of mass, momentum and energy in the transient form were solved numerically using the finite difference method. The stable, unstable and neutrally stable points were identified by examining the amplitude of flow and temperature oscillations with time for a given set of operating conditions. The stability behaviour of the loop has also been investigated using the linear stability theory. The results show that the stability maps obtained by the two methods are in close agreement.