Numerical analysis of influence of geometry and operating parameters on Ledinegg and dynamic instability on supercritical water natural circulation loop

Kumar, Shankar; Kumar, Pardeep; Panwar, Vinay

doi:10.1016/j.nucengdes.2020.110830

Cited by 17 publications

(5 citation statements)

References 16 publications

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“…Table 1. Details of all the parts and operating systems of the SCWNCL [32]. The boundary conditions, as well as the initial conditions, influence the solution of balancing coupled equations, and the steady-state solution is used as an initial condition for transient conservation equations.…”

Section: Detailed Description Of the Loopmentioning

confidence: 99%

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

et al. 2022

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Nowadays, a prime technology in generation IV nuclear reactors, the supercritical water reactor (SCWR), is the main object of focus. The current article aims to develop a thermal hydraulic numerical model for predicting density wave oscillation (DWO) in a supercritical water natural circulation loop (SCWNCL). A one-dimensional thermal hydraulic mathematical model was developed. The numerical model consists of nonlinear mass, momentum, and energy conservation equations, which were discretized by applying the implicit finite difference technique. The numerical model was validated with experimental results, and numerical simulations were carried out to find the marginal stability boundary (MSB) and draw the stability map for the loop. Further, the effects of geometry (i.e., diameter and hot leg length) and operating parameters (i.e., inlet system pressure and friction factor) on the density wave oscillation of the SCWNCL were analyzed.

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Section: Detailed Description Of the Loopmentioning

confidence: 99%

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

et al. 2022

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“…The present mathematical model is a simple one dimension nonlinear coupled balance mass, momentum and energy equations, which properties are varying along the axial direction. These balance equations are solved numerically [27][28][29][30][31][32][33].…”

Section: Development Of the Mathematical Modelmentioning

confidence: 99%

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

Kumar

Ahlawat

Kumar³

et al. 2021

E3S Web Conf.

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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.

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“…Recently, flow instability has gained massive attention from researchers since large magnitudes and continuous flow fluctuations can cause mechanical vibrations, disrupt control systems, and cause operational issues. Therefore, flow instabilities are widely studied experimentally [10][11][12][13] as well as numerically [14][15][16][17][18][19]. The discussion reveals that the real dynamics of the above-discussed systems are complex and complicated.…”

Section: Introductionmentioning

confidence: 99%

“…Rai [19,35,36] has studied and reviewed flow instabilities for supercritical natural circulation systems. They observed the static and dynamic stability characteristics for supercritical natural circulation loops and carried out the sensitivity analysis of geometric and operating parameters.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Nodalization Schemes on the Stability Characteristics of a Three Heated Channels under Supercritical Flow Condition

Singh

Berrouk

Saeed³

2022

Energies

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The present analysis is aimed at conducting node sensitivity analysis on the thermal–hydraulic performance of supercritical fluid in a three parallel channel configuration system. The heated channel was divided into different nodes and is examined under wide-ranging operating conditions. Firstly, the heated channel was divided into two nodes, like the two-phase flow system. In the second case, based on the correlation between the fluid properties, the heated channel was divided into three regions: heavy, mixture, and supercritical fluids. Finally, the channel was divided into N-nodes. Post the nodalization analysis, a non-linear analysis of three parallel channels was carried out under varied heat flux conditions. The analytical approximation functions were developed to capture the fluid flow dynamics. These functions were used to capture each node’s density, enthalpy, and velocity profiles under a wide range of operating conditions. The different flow instability (density wave oscillations and static) characteristics were observed at low pseudo- and relatively high subcooling numbers. In the density wave oscillations regime, out-of-phase oscillations and limit cycles are observed. A co-dimension parametric analysis with numerical simulations was carried out to confirm the obtained non-linear characteristics. Such analysis for parallel channel systems under supercritical working fluid flow conditions is missing in the literature which is limited to only linear stability analysis. This analysis can help to improve heat and mass transfer for designing efficient heated channel systems.

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Numerical analysis of influence of geometry and operating parameters on Ledinegg and dynamic instability on supercritical water natural circulation loop

Cited by 17 publications

References 16 publications

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

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

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

The Effect of Nodalization Schemes on the Stability Characteristics of a Three Heated Channels under Supercritical Flow Condition

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