The fast Fourier transform based method (FFTBM) was proposed in the 1990s and is used for accuracy quantification of computer codes. FFTBM provides frequency-based measures for each single TH variables as well as the whole transient calculations. The measurement-prediction discrepancies in the frequency domain are assessed by the average amplitude (AA), which is dependent to the proper selection of time windows, weighting factors, number of discrete data used. This paper summaries the application of FFTBM from publications in the last 30 years based on the previous review papers. It attempts to provide some insights and guidelines for FFTBM application. The second part deals with the applications of FFTBM for code accuracy quantification, to perform a sensitivity analysis on loss coefficients at geometric discontinuities in the framework of a virtual benchmark activity. RELAP5/MOD3.3 code was used for calculation, with qualified nodalizations for PKL test facility. The objective of the virtual benchmark and the sensitivity calculation is to investigate the impact of pressure drop modeling inadequacies in the selected transients.
FFTBM assessment of reverse natural circulation transient in PKL test facility
Cai Q.;Francesco D’Auria
Co-primo
Conceptualization
;
2023-01-01
Abstract
The fast Fourier transform based method (FFTBM) was proposed in the 1990s and is used for accuracy quantification of computer codes. FFTBM provides frequency-based measures for each single TH variables as well as the whole transient calculations. The measurement-prediction discrepancies in the frequency domain are assessed by the average amplitude (AA), which is dependent to the proper selection of time windows, weighting factors, number of discrete data used. This paper summaries the application of FFTBM from publications in the last 30 years based on the previous review papers. It attempts to provide some insights and guidelines for FFTBM application. The second part deals with the applications of FFTBM for code accuracy quantification, to perform a sensitivity analysis on loss coefficients at geometric discontinuities in the framework of a virtual benchmark activity. RELAP5/MOD3.3 code was used for calculation, with qualified nodalizations for PKL test facility. The objective of the virtual benchmark and the sensitivity calculation is to investigate the impact of pressure drop modeling inadequacies in the selected transients.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
