Mathematical modeling and numerical investigation of density wave instability of supercritical natural circulation loop

Abstract

In present paper, a mathematical model based on the one dimensional nonlinear mass, momentum and energy conservation equations has been developed to study the density wave instability (DWI) in horizontal heater and horizontal cooler supercritical water natural circulation loop (HHHC-SCWNCL). The one dimensional nonlinear mass, momentum and energy conservation equations are discretized by using finite difference method (FDM). The numerical model is validated with the benchmark results (NOLSTA model). Numerical simulations are performed to find the threshold stability zone (TSZ) and draw the stability map for natural circulation loop. Further, effect of change in diameter and riser height on the density wave instability of SCWNCL has been investigated.

A Study on the Effect of Geometry and Operating Variables on Density Wave Oscillation in a Supercritical Natural Circulation Loop

“…The potential of the present code to simulate the behavior of SCNCL has already been validated with numerical code SPORT [17], SUCLIN [35], and NOLSTA [36] by Rai et al [37]. Further, the results obtained from present numerical mathematical model have been compared with the experimental results for the HHHC loop reported by Sharma et al [38].…”

“…The criterion of DWI is given in Equation ( 13). This method has already been used by Rai et al [37] to demonstrate the transient instability mechanism in the loop.…”