Icone11-36583 Nuclear-Coupled Thermal-Hydraulic Nonlinear Stability Analysis Using a Novel BWR Reduced Order Model : Part 1-the Effects of Using Drift Flux Versus Homogeneous Equilibrium Models

Dokhane, A.; Hennig, D.; Chawla, R.; Uddin, Rizwan

doi:10.1299/jsmeicone.2003.443

Cited by 8 publications

(27 citation statements)

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“…A successor to BIFOR2, called BIFDD (Hassard, 1987), was used by van Bragt, Rizwan-uddin and van Der Hagen for bifurcation analysis of nuclear-coupled thermal hydraulics in natural circulation BWRs (van Bragt et al, 1999(van Bragt et al, , 2000. Bifurcation analyses similar to those reported here have recently been reported (Zhou and Rizwan-uddin, 2002, 2004, 2005Dokhane et al, 2002Dokhane et al, , 2003aDokhane et al, , 2003b. However, they are restricted to stability and "local" bifurcation analyses.…”

Section: Past Work On Bifurcation Analysismentioning

confidence: 75%

Turning points and sub- and supercritical bifurcations in a simple BWR model

Rizwan-uddin

2006

Nuclear Engineering and Design

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Section: Past Work On Bifurcation Analysismentioning

confidence: 75%

Turning points and sub- and supercritical bifurcations in a simple BWR model

Rizwan-uddin

2006

Nuclear Engineering and Design

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“…Hopf bifurcation has been reported by many researchers [Achard et al, 1985;Rizwan-uddin & Dorning, 1986;Muñoz-Cobo & Verdú, 1991;Tsuji et al, 1993;Karve et al, 1997;van der Bragt et al, 1999;Dokhane et al, 2003] to be the most important type of bifurcation observed during heated channel and boiling water reactor (BWR) stability analysis. Generally speaking, Hopf bifurcation theory states that stable or unstable periodic solutions to a set of nonlinear differential equations exist under certain conditions.…”

Section: Hopf Bifurcationmentioning

confidence: 99%

Semi-Analytical Bifurcation Analysis of Two-Phase Flow in a Heated Channel

Dokhane

Hennig

Chawla

et al. 2005

Int. J. Bifurcation Chaos

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Using a drift flux representation for the two-phase flow, a new reduced order model has been developed to simulate density-wave oscillations (DWOs) in a heated channel. This model is then used to perform stability and semi-analytical bifurcation analysis, using the bifurcation code BIFDD, in which the stability boundary (SB) and the nature of Hopf bifurcation are determined in a suitable two-dimensional parameter space. A comparative study is carried out to investigate the effects of the parameters in the drift flux model (DFM) — the radially void distribution parameter C0 and the drift velocity Vgj — on the SB as well as on the nature of Hopf bifurcation. It is the first time that a systematic analysis has been carried out to investigate the effects of DFM parameters on the nature of Hopf bifurcation in a heated-channel two-phase flow. The results obtained show that both sub- and super-critical Hopf bifurcations are encountered. In addition, it has been found that, while the SB is sensitive to both C0 and Vgj, the nature of Hopf bifurcation for lower values of N sub is more sensitive to Vgj than to C0. Numerical integration of the set of ODEs is carried out to confirm the predictions of the semi-analytical bifurcation analysis.

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“…From theoretical and experimental studies, it is well known that for a boiling water reactor (BWR) plant there exists operational points (characterized by a given thermal power, core coolant flow, core inlet subcooling and control rod position) where slowly decaying or non-decaying power oscillations are observed [1][2][3][4][5][6]. Global or in-phase oscillations and regional or out-of-phase oscillations are two kinds of observed power oscillations.…”

Section: Introductionmentioning

confidence: 99%

“…In the in-phase mode, the fundamental mode oscillates, while in the out-of-phase mode the first azimuthal mode oscillates: when the power or flow rises in one half of the core, it decreases in the other half in such a way that the total mass flow and the core power remain constant. The physical mechanism behind the stable and unstable oscillatory behavior is based on the coupling between the neutron kinetics and the thermal hydraulics via the void and Doppler feedback reactivity [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…The dynamics of boiling water reactors (BWR) can be described by a system of coupled nonlinear partial differential equations. From the nonlinear dynamics point of view, it is well known that such systems show, under specific conditions, very complex behavior which is reflected in the solution manifold of the corresponding equation system [1][2][3][4][5][6][7][8][9]. Consequently, to understand the nonlinear stability behavior of a BWR, the solution manifold of the differential equation systems must be examined.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Icone15-10568 Advanced BWR Stability Analysis With a Reduced Order Model and System Code

Lange

Hennig

García³

et al. 2007

ICONE

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The solution manifold of the system of nonlinear differential equations representing a BWR needs to be examined to understand its dynamical behavior. In particular, stable or unstable fixed points and stable or unstable oscillatory solutions (or turning points/saddle node bifurcations) are of paramount interest. In this framework integrated BWR (system) codes and simplified BWR models (reduced order models, ROM) are used together to reveal the solution manifold of the nonlinear differential equations describing the system. This work is a continuation of the previous work at the Paul Scherrer Institute (PSI, Switzerland) and University of Illinois (USA) on this field. The ROM developed at PSI was upgraded by introducing the recirculation loop, subcooled boiling and modification to the feedback reactivity calculation. The upgraded ROM has been coupled with the BIFDD code which performs semi-analytical bifurcation analysis. The methodology and some results of the semi-analytical bifurcation analysis of the modified ROM will be demonstrated and discussed. The stability boundary (SB) and the nature of the Poincarè-Andronov-Hopf bifurcation (PAH-B) are determined and visualized in appropriate two-dimensional parameter maps. Furthermore, for independent confirmation of the results, numerical integrations of the ROM differential equations have been carried out in the MATLAB environment.

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Icone11-36583 Nuclear-Coupled Thermal-Hydraulic Nonlinear Stability Analysis Using a Novel BWR Reduced Order Model : Part 1-the Effects of Using Drift Flux Versus Homogeneous Equilibrium Models

Cited by 8 publications

References 0 publications

Turning points and sub- and supercritical bifurcations in a simple BWR model

Turning points and sub- and supercritical bifurcations in a simple BWR model

Semi-Analytical Bifurcation Analysis of Two-Phase Flow in a Heated Channel

Icone15-10568 Advanced BWR Stability Analysis With a Reduced Order Model and System Code

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