Improvements to a dual-time-stepping method for computating unsteady flows

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1548-1550 ◽  
Author(s):  
S. DeRango ◽  
D. W. Zingg
Keyword(s):  
Unsteady Flows ◽  
Time Stepping ◽  
Dual Time Stepping

Numerical Solution of Incompressible Unsteady Flows in Turbomachinery

2000 ◽  
Vol 123 (3) ◽  
pp. 680-685 ◽  
Author(s):  
L. He ◽  
K. Sato
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Unsteady Flows ◽  
Navier Stokes ◽  
Time Step ◽  
Navier Stokes Equations ◽  
Flow Solver ◽  
Time Stepping ◽  
Incompressible Viscous Flow ◽  
Dual Time Stepping

A three-dimensional incompressible viscous flow solver of the thin-layer Navier-Stokes equations was developed for the unsteady turbomachinery flow computations. The solution algorithm for the unsteady flows combines the dual time stepping technique with the artificial compressibility approach for solving the incompressible unsteady flow governing equations. For time accurate calculations, subiterations are introduced by marching the equations in the pseudo-time to fully recover the incompressible continuity equation at each real time step, accelerated with a multi-grid technique. Computations of test cases show satisfactory agreements with corresponding theoretical and experimental results, demonstrating the validity and applicability of the present method to unsteady incompressible turbomachinery flows.

scholarly journals Blending Dual Time Stepping and Newton-Krylov Methods for Unsteady Flows

PAMM ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 597-598
Author(s):  
Philipp Birken ◽  
Antony Jameson
Keyword(s):  
Unsteady Flows ◽  
Krylov Methods ◽  
Time Stepping ◽  
Dual Time Stepping

Investigation of the Unsteady Flow for the Supersonic Jet Element

2011 ◽  
Vol 201-203 ◽  
pp. 2178-2181 ◽  
Author(s):  
Yong Xu ◽  
Guo Qing Zhang ◽  
Fei Wang
Keyword(s):  
Unsteady Flow ◽  
Viscous Flow ◽  
Supersonic Jet ◽  
Unsteady Flows ◽  
Time Stepping ◽  
Dual Time Stepping ◽  
Unsteady Viscous Flow ◽  
Thrust Fluctuation

The unsteady viscous flow of the supersonic jet element (SJE) was simulated numerically based on CFD technology. A dual time-stepping scheme and AMG scheme were employed to solve the unsteady flows in SJE, and the reasons of thrust fluctuation during the wall-attachment state of SJE are found out. Based on the pressure cloud and streamlines, the vortices generated by the unsteady flow on attached wall had also been investigated and drawn some conclusions.

Application of an implicit dual-time stepping multi-block solver to 3D unsteady flows

2006 ◽  
pp. 309-316
Author(s):  
R. Steijl ◽  
P. Nayyar ◽  
M.A. Woodgate ◽  
K.J. Badcock ◽  
G.N. Barakos
Keyword(s):  
Unsteady Flows ◽  
Time Stepping ◽  
Dual Time Stepping

Improvements to a Dual-Time-Stepping Method for Computing Unsteady Flows

AIAA Journal ◽  
1997 ◽  
Vol 35 (9) ◽  
pp. 1548-1550 ◽  
Author(s):  
S. DeRango ◽  
D. W. Zingg
Keyword(s):  
Unsteady Flows ◽  
Time Stepping ◽  
Dual Time Stepping

scholarly journals Dual Time Stepping Algorithms With the High Order Harmonic Balance Method for Contact Interfaces With Fretting-Wear

2011 ◽  
Author(s):  
Loi¨c Salles ◽  
Laurent Blanc ◽  
Fabrice Thouverez ◽  
Alexander M. Gouskov ◽  
Pierrick Jean
Keyword(s):  
Frequency Domain ◽  
Dry Friction ◽  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Contact Forces ◽  
Balance Method ◽  
Fretting Wear ◽  
Rate Equations ◽  
Time Stepping ◽  
Dual Time Stepping

Contact interfaces with dry friction are frequently used in turbomachinery. Dry friction damping produced by the sliding surfaces of these interfaces reduces the amplitude of bladed-disk vibration. The relative displacements at these interfaces lead to fretting-wear which reduces the average life expectancy of the structure. Frequency response functions are calculated numerically by using the multi-Harmonic Balance Method (mHBM). The Dynamic Lagrangian Frequency-Time method is used to calculate contact forces in the frequency domain. A new strategy for solving non-linear systems based on dual time stepping is applied. This method is faster than using Newton solvers. It was used successfully for solving Nonlinear CFD equations in the frequency domain. This new approach allows identifying the steady state of worn systems by integrating wear rate equations a on dual time scale. The dual time equations are integrated by an implicit scheme. Of the different orders tested, the first order scheme provided the best results.

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