• Neetesh Singh Raghuvanshi
• Raghvendra Upadhyay

The natural circulation loop is an experimental setup where the fluid flow is caused by the density difference between the hot and cold fluid. A mathematical model for a single-phase rectangular natural circulation loop (NCL) is developed to study steady-state behavior and flow instabilities. The numerical model incorporates the mass, momentum, and energy equation with the state equation. The steady-state and nonlinear stability analysis includes an implicit finite difference methodology using a fixed spatial and temporal grid distribution while discretizing the convective terms by backward or forward difference scheme. The steady-state analysis has captured the variation of mass flow rate with respect to power. It identifies the operating conditions where maximum mass flow rate occurs in an NCL. A comprehensive numerical study of the nonlinear stability analysis is performed with various parametric studies, which include the effect of loop diameter, loop height, operating pressure, orientation of heater and cooler and power profile. Furthermore, the stable operating zones are investigated by taking appropriate geometrical and operating conditions via stability analysis.

Flow instability, Marginal stability boundary, Natural circulation loop, Supercritical water.

"Steady-state and Nonlinear Stability Analysis of a Single-phase Rectangular Natural Circulation Loop", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 10, page no.1-8, October-2021, Available :http://www.jetir.org/papers/JETIRFD06001.pdf

"Steady-state and Nonlinear Stability Analysis of a Single-phase Rectangular Natural Circulation Loop", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 10, page no. pp1-8, October-2021, Available at : http://www.jetir.org/papers/JETIRFD06001.pdf