Akhil Dass
Department of Mechanical Engineering, IIT Madras, Chennai-600036, India
Sateesh Gedupudi
Indian Institute of Technology Madras, Chennai-600036, Tamil Nadu, India
The current work explores the influence of inclination on the stability map of a particular steady-state of a Coupled Natural Circulation Loop (CNCL) system. The CNCL is a simple version of the systems used in practice like the fast breeder reactors employing liquid metals and residual heat removal systems employed under emergency conditions. A Fourier series-based 1-D model of the CNCL is utilized to generate the stability maps. The stability of the CNCL system is carried using the linear stability analysis approach in the present work. The non-dimensional numbers which represent the CNCL system are Gr (Grashof number), St (Stanton number), Fo (Fourier number), As (Aspect ratio) and Co1 (Flow resistance coefficient) when each of the loops of the CNCL comprise of the identical fluid.
The stability map in the current work is presented in the Gr − St domain keeping the other non-dimensional
numbers fixed. It is observed from the study that the area
of stability (eigenvalue is negative) of the considered steady
state decreases with increase in inclination. The transient
behaviour of the system for different Gr and St and the transient variation of the buoyancy and viscous parameters are also studied to identify the cause for the observed chaotic oscillations.