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Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal / Zhigang Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Titre : Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal Type de document : texte imprimé Auteurs : Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal [texte imprimé] / Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur . - 2012 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Investigations on the rotordynamic coefficients of pocket damper seals using the multifrequency, one-dimensional, whirling orbit model and RANS solutions / Jun Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 10 (Octobre 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 10 (Octobre 2012) . - 11 p. Titre : Investigations on the rotordynamic coefficients of pocket damper seals using the multifrequency, one-dimensional, whirling orbit model and RANS solutions Type de document : texte imprimé Auteurs : Jun Li, Auteur ; Zhigang Li, Auteur ; Zhenping Feng, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : gas turbines Langues : Anglais (eng) Mots-clés : pocket  damper  seal;  rotordynamic  coefficient;  multifrequency;  one-dimentional;  whirling  orbit  model;  numerical  simulation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The numerical approach using the multifrequency one-dimensional whirling orbit model and Reynolds-averaged Navier-Stokes (RANS) solution was proposed for prediction of rotordynamic coefficients of pocket damper seal (PDS). By conducting the multiple frequencies one-dimensional whirling orbit for rotor center as the excitation signal, the unsteady RANS solutions combined with mesh deformation method were utilized to calculate the transient response forces on the PDS rotor surface. Unlike the single frequency whirling orbit models which require a separate computation for each frequency, the multifrequency whirling orbit model yields results for multiple frequencies and therefore requires only one computation for different frequencies. The rotor motion signal and response force signal were transformed to the frequency domain using the fast fourier transform, then the eight rotordynamic coefficients of the PDS were determined at fourteen different vibration frequencies 20–300 Hz. The numerical results of rotordynamic coefficients of the PDS were in good agreement with experimental data. The accuracy and availability of the proposed method was demonstrated. The effects of vibration frequencies and pressure ratios on the rotordynamic coefficients of PDS were also investigated using the presented numerical method. The multifrequency one-dimensional whirling orbit model is a promising method for prediction of the rotordynamic coefficients of the PDS. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000010 [...] [article] Investigations on the rotordynamic coefficients of pocket damper seals using the multifrequency, one-dimensional, whirling orbit model and RANS solutions [texte imprimé] / Jun Li, Auteur ; Zhigang Li, Auteur ; Zhenping Feng, Auteur . - 2012 . - 11 p. gas turbines Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 10 (Octobre 2012) . - 11 p. Mots-clés : pocket  damper  seal;  rotordynamic  coefficient;  multifrequency;  one-dimentional;  whirling  orbit  model;  numerical  simulation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The numerical approach using the multifrequency one-dimensional whirling orbit model and Reynolds-averaged Navier-Stokes (RANS) solution was proposed for prediction of rotordynamic coefficients of pocket damper seal (PDS). By conducting the multiple frequencies one-dimensional whirling orbit for rotor center as the excitation signal, the unsteady RANS solutions combined with mesh deformation method were utilized to calculate the transient response forces on the PDS rotor surface. Unlike the single frequency whirling orbit models which require a separate computation for each frequency, the multifrequency whirling orbit model yields results for multiple frequencies and therefore requires only one computation for different frequencies. The rotor motion signal and response force signal were transformed to the frequency domain using the fast fourier transform, then the eight rotordynamic coefficients of the PDS were determined at fourteen different vibration frequencies 20–300 Hz. The numerical results of rotordynamic coefficients of the PDS were in good agreement with experimental data. The accuracy and availability of the proposed method was demonstrated. The effects of vibration frequencies and pressure ratios on the rotordynamic coefficients of PDS were also investigated using the presented numerical method. The multifrequency one-dimensional whirling orbit model is a promising method for prediction of the rotordynamic coefficients of the PDS. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000010 [...]