Flow-Induced Vibration Analyses of Stator and Moving Rotor Cascade With Viscosity Effects

2007 ◽  
Author(s):  
Dong-Hyun Kim ◽  
Se-Won Oh ◽  
Yu-Sung Kim ◽  
Oung Park
Keyword(s):  
Stokes Equations ◽  
Turbulence Models ◽  
Dynamic Responses ◽  
Navier Stokes ◽  
Implicit Time ◽  
Flow Induced Vibration ◽  
Fluid Structure ◽  
Fully Implicit ◽  
Direct Integration Method ◽  
The Time Domain

In this study, nonlinear dynamic responses considering fluid-structure interactions have been conducted for a stator-rotor cascade configuration. Advanced computational analysis system based on computational fluid dynamics (CFD) and computational structural dynamics (CSD) has been developed in order to investigate detailed dynamic responses and flutter stability of general stator-rotor cascade configurations. Especially, effects of relative motions of the rotor cascade with respect to the stator cascade are considered in numerical analyses. Fluid domains are modeled using the unstructured grid system with dynamic moving and local deforming techniques. Unsteady, Reynolds-averaged Navier-Stokes equations with Spalart-Allmaras and SST k-ω turbulence models are solved for unsteady flow problems. A fully implicit time marching scheme based on the Newmark direct integration method is typically used for computing the coupled aeroelastic governing equations of the cascade fluid-structure interaction problems. Detailed dynamic aeroelastic responses for different stator-rotor interaction flow conditions are presented to show the physical vibration characteristics in the time-domain.

Rotor-Stator Interaction Analysis Using the Navier-Stokes Equations and a Multigrid Method

1995 ◽  
Author(s):  
Andrea Arnone ◽  
Roberto Pacciani
Keyword(s):  
Stokes Equations ◽  
Interaction Analysis ◽  
Time Discretization ◽  
Navier Stokes ◽  
Implicit Time ◽  
Navier Stokes Equations ◽  
Time Stepping ◽  
Fully Implicit ◽  
Rotor Stator Interaction ◽  
Stage Analysis

A recently developed, time-accurate multigrid viscous solver has been extended to the analysis of unsteady rotor-stator interaction. In the proposed method, a fully-implicit time discretization is used to remove stability limitations. By means of a dual time-stepping approach, a four-stage Runge-Kutta scheme is used in conjunction with several accelerating techniques typical of steady-state solvers, instead of traditional time-expensive factorizations. The accelerating strategies include local time stepping, residual smoothing, and multigrid. Two-dimensional viscous calculations of unsteady rotor-stator interaction in the first stage of a modem gas turbine are presented. The stage analysis is based on the introduction of several blade passages to approximate the stator:rotor count ratio. Particular attention is dedicated to grid dependency in space and time as well as to the influence of the number of blades included in the calculations.

Multigrid Computations of Unsteady Rotor-Stator Interaction Using the Navier-Stokes Equations

1995 ◽  
Vol 117 (4) ◽  
pp. 647-652 ◽  
Author(s):  
A. Arnone ◽  
R. Pacciani ◽  
A. Sestini
Keyword(s):  
Stokes Equations ◽  
Time Discretization ◽  
Navier Stokes ◽  
Implicit Time ◽  
Navier Stokes Equations ◽  
Time Stepping ◽  
Fully Implicit ◽  
Local Time Stepping ◽  
Rotor Stator Interaction ◽  
Residual Smoothing

A Navier-Stokes time-accurate solver has been extended to the analysis of unsteady rotor-stator interaction. In the proposed method, a fully-implicit time discretization is used to remove stability limitations. A four-stage Runge-Kutta scheme is used in conjunction with several accelerating techniques typical of steady-state solvers, instead of traditional time-expensive factorizations. Those accelerating strategies include local time stepping, residual smoothing, and multigrid. Direct interpolation of the conservative variables is used to handle the interfaces between blade rows. Two-dimensional viscous calculations of unsteady rotor-stator interaction in a modern gas turbine stage are presented to check for the capability of the procedure.

Preconditioning for the All-Speed Compressible Navier-Stokes Equations With Laser-Induced Phase Change

2017 ◽  
Author(s):  
Brian Weston ◽  
Jean-Pierre Delplanque ◽  
Robert Nourgaliev
Keyword(s):  
Phase Change ◽  
Acoustic Waves ◽  
Stokes Equations ◽  
Linear Equations ◽  
Time Discretization ◽  
Navier Stokes ◽  
Implicit Time ◽  
Material Strength ◽  
Fully Implicit ◽  
Block Based

We present a new block-based preconditioner for simulating all-speed compressible flow with phase change. The conservation equations are discretized with a reconstructed Discontinuous Galerkin method and integrated in time with fully implicit time discretization schemes. The resulting set of non-linear equations is converged using a robust Newton-Krylov framework. Due to the stiffness of the underlying physics associated with stiff acoustic waves and viscous material strength effects, we solve for the primitive-variables (pressure, velocity, and temperature). To enable convergence of the highly ill-conditioned linearized systems, we develop a physics-based preconditioner, utilizing approximate block factorization techniques to reduce the fully-coupled 3 × 3 system to a pair of reduced 2 × 2 systems. We demonstrate that our preconditioned Newton-Krylov framework converges on very stiff multi-physics problems with excellent algorithmic and parallel scalability. Results are shown for the classic lid-driven cavity flow problem as well as for 3D laser-induced phase change.

Unsteady Navier-Stokes Simulation of a Transonic Flutter Cascade Near Stall Conditions Applying Algebraic Transition Models

2005 ◽  
Author(s):  
Hans Thermann ◽  
Reinhard Niehuis
Keyword(s):  
Boundary Layer ◽  
Stokes Equations ◽  
Strong Shock ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Implicit Time ◽  
Compressor Cascade ◽  
Transonic Compressor ◽  
Transition Models ◽  
Operating Points

Due to the trend in the design of modern aeroengines to reduce weight and to realize high pressure ratios, fan and first stage compressor blades are highly susceptible to flutter. At operating points with transonic flow velocities and high incidences stall flutter might occur involving strong shock-boundary layer interactions, flow separation and oscillating shocks. In this paper, results of unsteady Navier-Stokes flow calculations around an oscillating blade in a linear transonic compressor cascade at different operating points including near stall conditions are presented. The nonlinear unsteady Reynolds-averaged Navier-Stokes equations are solved time-accurately using implicit time-integration. Different Low-Reynolds-Number turbulence models are used for closure. Furthermore, empirical algebraic transition models are applied to enhance the accuracy of prediction. Computations are performed two-dimensionally as well as three-dimensionally. It is shown that, for the steady calculations, the prediction of the boundary layer development and the blade loading can be substantially improved compared with fully turbulent computations when algebraic transition models are applied. Furthermore, it is shown that the prediction of the aerodynamic damping in the case of oscillating blades at near stall conditions can be dependent on the applied transition models.

Rotor-Stator Interaction Analysis Using the Navier–Stokes Equations and a Multigrid Method

1996 ◽  
Vol 118 (4) ◽  
pp. 679-689 ◽  
Author(s):  
A. Arnone ◽  
R. Pacciani
Keyword(s):  
Stokes Equations ◽  
Interaction Analysis ◽  
Time Discretization ◽  
Navier Stokes ◽  
Implicit Time ◽  
Navier Stokes Equations ◽  
Time Stepping ◽  
Fully Implicit ◽  
Rotor Stator Interaction ◽  
Stage Analysis

A recently developed, time-accurate multigrid viscous solver has been extended to the analysis of unsteady rotor–stator interaction. In the proposed method, a fully implicit time discretization is used to remove stability limitations. By means of a dual time-stepping approach, a four-stage Runge–Kutta scheme is used in conjunction with several accelerating techniques typical of steady-state solvers, instead of traditional time-expensive factorizations. The accelerating strategies include local time stepping, residual smoothing, and multigrid. Two-dimensional viscous calculations of unsteady rotor–stator interaction in the first stage of a modern gas turbine are presented. The stage analysis is based on the introduction of several blade passages to approximate the stator:rotor count ratio. Particular attention is dedicated to grid dependency in space and time as well as to the influence of the number of blades included in the calculations.

Unsteady Navier-Stokes Simulation of a Transonic Flutter Cascade Near-Stall Conditions Applying Algebraic Transition Models

2005 ◽  
Vol 128 (3) ◽  
pp. 474-483 ◽  
Author(s):  
Hans Thermann ◽  
Reinhard Niehuis
Keyword(s):  
Boundary Layer ◽  
Stokes Equations ◽  
Strong Shock ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Implicit Time ◽  
Compressor Cascade ◽  
Transonic Compressor ◽  
Transition Models ◽  
Operating Points

Due to the trend in the design of modern aeroengines to reduce weight and to realize high pressure ratios, fan and first-stage compressor blades are highly susceptible to flutter. At operating points with transonic flow velocities and high incidences, stall flutter might occur involving strong shock-boundary layer interactions, flow separation, and oscillating shocks. In this paper, results of unsteady Navier-Stokes flow calculations around an oscillating blade in a linear transonic compressor cascade at different operating points including near-stall conditions are presented. The nonlinear unsteady Reynolds-averaged Navier-Stokes equations are solved time accurately using implicit time integration. Different low-Reynolds-number turbulence models are used for closure. Furthermore, empirical algebraic transition models are applied to enhance the accuracy of prediction. Computations are performed two dimensionally as well as three dimensionally. It is shown that, for the steady calculations, the prediction of the boundary layer development and the blade loading can be substantially improved compared with fully turbulent computations when algebraic transition models are applied. Furthermore, it is shown that the prediction of the aerodynamic damping in the case of oscillating blades at near-stall conditions can be dependent on the applied transition models.

Simulation of the Transitional Flow in a Low Pressure Gas Turbine Cascade With a High-Order Discontinuous Galerkin Method

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
A. Ghidoni ◽  
A. Colombo ◽  
S. Rebay ◽  
F. Bassi
Keyword(s):  
Discontinuous Galerkin ◽  
Turbulence Model ◽  
Stokes Equations ◽  
Time Integration ◽  
High Order ◽  
Transitional Flow ◽  
Navier Stokes ◽  
Implicit Time ◽  
Turbine Cascade ◽  
High Reynolds

In the last decade, discontinuous Galerkin (DG) methods have been the subject of extensive research efforts because of their excellent performance in the high-order accurate discretization of advection-diffusion problems on general unstructured grids, and are nowadays finding use in several different applications. In this paper, the potential offered by a high-order accurate DG space discretization method with implicit time integration for the solution of the Reynolds-averaged Navier–Stokes equations coupled with the k-ω turbulence model is investigated in the numerical simulation of the turbulent flow through the well-known T106A turbine cascade. The numerical results demonstrate that, by exploiting high order accurate DG schemes, it is possible to compute accurate simulations of this flow on very coarse grids, with both the high-Reynolds and low-Reynolds number versions of the k-ω turbulence model.

scholarly journals Choice and Limits of a Fluid Model for the Numerical Study in Dynamic Fluid Structure Interaction Problems

2003 ◽  
Author(s):  
Jean Franc¸ois Sigrist ◽  
Christian Laine ◽  
Dominique Lemoine ◽  
Bernard Peseux
Keyword(s):  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Model ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Linear Solution ◽  
Fluid Structure ◽  
Design Engineers ◽  
Inviscid Incompressible Fluid ◽  
Basic Fluid

This paper is related to the study of a nuclear propulsion reactor prototype for the French Navy. This prototype is built on ground and is to be dimensioned toward seismic loading. The dynamic analysis takes the coupled fluid structure analysis into account. The basic fluid models used by design engineers are inviscid incompressible or compressible. The fluid can be described in a bidimensional by slice or a three-dimensional approach. A numerical study is carried out on a generic problem for the linear FSI dynamic problem. The results of this study are presented and discussed. As a conclusion, the three-dimensional inviscid incompressible fluid appears to be the best compromise between the description of physical phenomena and the cost of modeling. The geometry of the reactor is such that large displacements of the structure in the fluid can occur. Therefore, the linearity hypothesis might not be longer valid. The case of large amplitude imposed oscillating motion of a cylinder in a confined fluid is numerically studied. A CFD code is used to investigate the fluid behavior solving the NAVIER-STOKES equations. The forces induced on the cylinder by the fluid are computed and compared to the linear solution. The limit of the linear model can then be exhibited.

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