The Experts below are selected from a list of 50661 Experts worldwide ranked by ideXlab platform

G Palani - One of the best experts on this subject based on the ideXlab platform.

  • Finite Difference Analysis of unsteady natural convection mhd flow past an inclined plate with variable surface heat and mass flux
    International Journal of Heat and Mass Transfer, 2004
    Co-Authors: P. Ganesan, G Palani
    Abstract:

    Abstract A numerical solution of the transient free convection MHD flow of an incompressible viscous fluid past a semi-inFinite inclined plate with variable surface heat and mass flux is presented here. The non-dimensional governing equations of the flow are unsteady, coupled and non-linear integro partial differential equations. The governing equations are solved by an efficient, more accurate and unconditionally stable implicit Finite Difference scheme. Velocity, temperature and concentration of the flow have been presented for various parameters such as Prandtl number, Schmidt number, the buoyancy ratio parameter, Grashof number, inclination angle φ and the magnetic parameter. The local and average skin friction, Nusselt number and Sherwood number are also presented graphically.

Masaharu Uchiumi - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear Analysis of Rotordynamic Fluid Forces in the Annular Plain Seal by Using Extended Bulk-Flow Analysis: Influence of Static Eccentricity and Whirling Amplitude
    Journal of Engineering for Gas Turbines and Power, 2018
    Co-Authors: Koya Yamada, Atsushi Ikemoto, Tsuyoshi Inoue, Masaharu Uchiumi
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbomachinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. The conventional bulk flow theory has been carried out under the assumption of concentric circular shaft's orbit with a small amplitude. However, actual rotating machinery's operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of the RD fluid force in such a situation. In this paper, the RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate the RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. The RD fluid force for such cases is analyzed, and the occurrence of constant component, backward synchronous component, and super-harmonic components in the RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.

  • NONLINEAR Analysis OF ROTORDYNAMIC FLUID FORCES IN THE ANNULAR PLAIN SEAL BY USING EXTENDED BULK-FLOW Analysis (INFLUENCE OF STATIC ECCENTRICITY AND WHIRLING AMPLITUDE)
    Volume 7B: Structures and Dynamics, 2018
    Co-Authors: Koya Yamada, Masaharu Uchiumi, Atsushi Ikemoto, Tsuyoshi Inoue
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbo-machinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. Conventional bulk flow theory has been carried out under the assumption of concentric circular shaft’s orbit with small amplitude. However, actual rotating machinery’s operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of RD fluid force in such situation. In this paper, RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. RD fluid force for such cases are analyzed, and the occurrence of constant component, backward synchronous component and super-harmonic components in RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.

P. Ganesan - One of the best experts on this subject based on the ideXlab platform.

  • Finite Difference Analysis of unsteady natural convection mhd flow past an inclined plate with variable surface heat and mass flux
    International Journal of Heat and Mass Transfer, 2004
    Co-Authors: P. Ganesan, G Palani
    Abstract:

    Abstract A numerical solution of the transient free convection MHD flow of an incompressible viscous fluid past a semi-inFinite inclined plate with variable surface heat and mass flux is presented here. The non-dimensional governing equations of the flow are unsteady, coupled and non-linear integro partial differential equations. The governing equations are solved by an efficient, more accurate and unconditionally stable implicit Finite Difference scheme. Velocity, temperature and concentration of the flow have been presented for various parameters such as Prandtl number, Schmidt number, the buoyancy ratio parameter, Grashof number, inclination angle φ and the magnetic parameter. The local and average skin friction, Nusselt number and Sherwood number are also presented graphically.

  • Finite Difference Analysis of unsteady natural convection flow along an inclined plate with variable surface temperature and mass diffusion
    Heat and Mass Transfer, 1995
    Co-Authors: K. Ekambavanan, P. Ganesan
    Abstract:

    Die Untersuchung bezieht sich auf die nichtstationäre, natürliche Konvektionsströmung entlang einer geneigten, halbunendlichen Platte, deren Wandtemperatur T _ w ^′ und Wandkonzentration C _ w ^′ eine Potenzfunktion der Längskoordinate, gemäß T _ w ^′ (x) = T _∞+ ax ^ n und C _ w = C _∞+ bx ^ m sind. Die dimensionslosen Grundgleichungen sind nichtstationäre, zweidimensionale, gekoppelte und nichtlineare Integro-Differentialgleichungen. Die Lösung erfolgt mittels eines Finite-Elementschemas vom Crank-Nicolson Typ. Abhängig von einem Satz variierter Parameter werden Geschwindigkeits-, Temperatur- und Konzentrationsfelder, der Reibungswert sowie die Nusselt- und Sherwood-Zahl ermittelt. Bezüglich letzterer finden sich in der Arbeit Korrelationsbeziehungen als Funktionen der variierten Parameter. An Analysis is performed to study the transient laminar natural convection flows along an inclined semi-inFinite flat plate in which the wall temperature T _ w ^′ and species concentration on the wall C _ w ^′ vary as the power of the axial co-ordinate in the form T _ w ^′ (x) = T _∞ ^′ + ax ^ n and C _ w ^′ = C _∞ ^′ + bx ^ m respectively. The dimensionless governing equations considered here are unsteady, two-dimensional, coupled and non-linear integro-differential equations. A Finite Difference scheme of Crank-Nicolson type is employed to solve the problem. The velocity, temperature, concentration, skin friction, Nusselt number and Sherwood number are studied in detail for various sets of values of parameters. Correlation equations are also established for Nusselt number and Sherwood number in terms of parameters.

Koya Yamada - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear Analysis of Rotordynamic Fluid Forces in the Annular Plain Seal by Using Extended Bulk-Flow Analysis: Influence of Static Eccentricity and Whirling Amplitude
    Journal of Engineering for Gas Turbines and Power, 2018
    Co-Authors: Koya Yamada, Atsushi Ikemoto, Tsuyoshi Inoue, Masaharu Uchiumi
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbomachinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. The conventional bulk flow theory has been carried out under the assumption of concentric circular shaft's orbit with a small amplitude. However, actual rotating machinery's operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of the RD fluid force in such a situation. In this paper, the RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate the RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. The RD fluid force for such cases is analyzed, and the occurrence of constant component, backward synchronous component, and super-harmonic components in the RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.

  • NONLINEAR Analysis OF ROTORDYNAMIC FLUID FORCES IN THE ANNULAR PLAIN SEAL BY USING EXTENDED BULK-FLOW Analysis (INFLUENCE OF STATIC ECCENTRICITY AND WHIRLING AMPLITUDE)
    Volume 7B: Structures and Dynamics, 2018
    Co-Authors: Koya Yamada, Masaharu Uchiumi, Atsushi Ikemoto, Tsuyoshi Inoue
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbo-machinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. Conventional bulk flow theory has been carried out under the assumption of concentric circular shaft’s orbit with small amplitude. However, actual rotating machinery’s operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of RD fluid force in such situation. In this paper, RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. RD fluid force for such cases are analyzed, and the occurrence of constant component, backward synchronous component and super-harmonic components in RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.

Tsuyoshi Inoue - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear Analysis of Rotordynamic Fluid Forces in the Annular Plain Seal by Using Extended Bulk-Flow Analysis: Influence of Static Eccentricity and Whirling Amplitude
    Journal of Engineering for Gas Turbines and Power, 2018
    Co-Authors: Koya Yamada, Atsushi Ikemoto, Tsuyoshi Inoue, Masaharu Uchiumi
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbomachinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. The conventional bulk flow theory has been carried out under the assumption of concentric circular shaft's orbit with a small amplitude. However, actual rotating machinery's operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of the RD fluid force in such a situation. In this paper, the RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate the RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. The RD fluid force for such cases is analyzed, and the occurrence of constant component, backward synchronous component, and super-harmonic components in the RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.

  • NONLINEAR Analysis OF ROTORDYNAMIC FLUID FORCES IN THE ANNULAR PLAIN SEAL BY USING EXTENDED BULK-FLOW Analysis (INFLUENCE OF STATIC ECCENTRICITY AND WHIRLING AMPLITUDE)
    Volume 7B: Structures and Dynamics, 2018
    Co-Authors: Koya Yamada, Masaharu Uchiumi, Atsushi Ikemoto, Tsuyoshi Inoue
    Abstract:

    Rotor-dynamic fluid force (RD fluid force) of turbo-machinery is one of the causes of the shaft vibration problem. Bulk flow theory is the method for analyzing this RD fluid force, and it has been widely used in the design stage of machine. Conventional bulk flow theory has been carried out under the assumption of concentric circular shaft’s orbit with small amplitude. However, actual rotating machinery’s operating condition often does not hold this assumption, for example, existence of static load on the machinery causes static eccentricity. In particular, when such a static eccentricity is significant, the nonlinearity of RD fluid force may increase and become non-negligible. Therefore, conventional bulk flow theory is not applicable for the Analysis of RD fluid force in such situation. In this paper, RD fluid force of the annular plain seal in the case of circular whirling orbit with static eccentricity is investigated. The case with both the significant static eccentricity and the moderate whirling amplitude is considered, and the perturbation Analysis of the bulk-flow theory is extended to investigate RD fluid force in such cases. In this Analysis, the assumption of the perturbation solution is extended to both static terms and whirling terms up to the third order. Then, the additional terms are caused by the coupling of these terms through nonlinearity, and these three kinds of terms are considered in the extended perturbation Analysis of the bulk flow theory. As a result, a set of nonlinear analytical equations of the extended perturbation Analysis of the bulk flow theory, for the case with both the significant static eccentricity and the moderate whirling amplitude, is deduced. RD fluid force for such cases are analyzed, and the occurrence of constant component, backward synchronous component and super-harmonic components in RD fluid force is observed in addition to the forward synchronous component. The representation of RD fluid force coefficients (RD coefficients) are modified for the case with significant static eccentricity, and the variation of RD fluid force coefficients for the magnitude of static eccentricity is analyzed. These analytical results of RD fluid force and its RD coefficients are compared with the numerical results using Finite Difference Analysis and experimental results. As a result, the validity of the extended perturbation Analysis of the bulk-flow theory for the case with both the significant static eccentricity and the moderate whirling amplitude is confirmed.