On nonreflecting projective characteristic boundary condition and its application in the numerical simulation of asymmetric coronal structures

2001 ◽  
Vol 46 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Jingqun Li ◽  
Fengsi Wei
Keyword(s):  
Numerical Simulation ◽  
Boundary Condition ◽  
Characteristic Boundary ◽  
Characteristic Boundary Condition ◽  
Coronal Structures

NUMERICAL SIMULATION OF FREE VORTEX WITH MODIFIED NAVIER–STOKES CHARACTERISTIC BOUNDARY CONDITIONS

2010 ◽  
Vol 24 (13) ◽  
pp. 1333-1336
Author(s):  
LIN CHEN ◽  
DENGBIN TANG ◽  
XIN GUO
Keyword(s):  
Boundary Condition ◽  
Compressible Flows ◽  
Diffusion Processes ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Free Vortex ◽  
Navier Stokes Equations ◽  
Characteristic Boundary ◽  
Accurate Treatment ◽  
Characteristic Boundary Condition

The convection and diffusion processes of free vortex in compressible flows are simulated by using high precision numerical method to solve for the Navier–Stokes equations. Accurate treatment of the boundary condition is extremely important for simulation of vortex flows. The developed numerical methods are well presented by combining six-order non-dissipation compact schemes with Navier–Stokes characteristic boundary condition having transverse and viscous terms, and can accurately simulate the movement of free vortex. The numerical reflecting waves at the boundaries are well controlled.

scholarly journals A Low Dissipative and Stable Cell-Centered Finite Volume Method with the Simultaneous Approximation Term for Compressible Turbulent Flows

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1206
Author(s):  
Myeongseok Kang ◽  
Donghyun You
Keyword(s):  
Boundary Condition ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Simultaneous Approximation ◽  
Summation By Parts ◽  
Eddy Simulation ◽  
Characteristic Boundary ◽  
Simultaneous Approximation Term ◽  
Characteristic Boundary Condition ◽  
Volume Method

A simultaneous-approximation term is a non-reflecting boundary condition that is usually accompanied by summation-by-parts schemes for provable time stability. While a high-order convective flux based on reconstruction is often employed in a finite-volume method for compressible turbulent flow, finite-volume methods with the summation-by-parts property involve either equally weighted averaging or the second-order central flux for convective fluxes. In the present study, a cell-centered finite-volume method for compressible Naiver–Stokes equations was developed by combining a simultaneous-approximation term based on extrapolation and a low-dissipative discretization method without the summation-by-parts property. Direct numerical simulations and a large eddy simulation show that the resultant combination leads to comparable non-reflecting performance to that of the summation-by-parts scheme combined with the simultaneous-approximation term reported in the literature. Furthermore, a characteristic boundary condition was implemented for the present method, and its performance was compared with that of the simultaneous-approximation term for a direct numerical simulation and a large eddy simulation to show that the simultaneous-approximation term better maintained the average target pressure at the compressible flow outlet, which is useful for turbomachinery and aerodynamic applications, while the characteristic boundary condition better preserved the flow field near the outlet.

A Consistent Characteristic Boundary Condition for General Fluid Mixture and Its Implementation in a Preconditioning Scheme

2012 ◽  
Vol 4 (1) ◽  
pp. 72-92 ◽  
Author(s):  
Hua-Guang Li ◽  
Nan Zong ◽  
Xi-Yun Lu ◽  
Vigor Yang
Keyword(s):  
Boundary Condition ◽  
Acoustic Waves ◽  
Fluid Flows ◽  
Computational Domain ◽  
Fluid Mixture ◽  
Characteristic Boundary ◽  
Flow Speeds ◽  
Flow Features ◽  
Characteristic Boundary Condition ◽  
Pass Through

AbstractCharacteristic boundary conditions that are capable of handling general fluid mixtures flow at all flow speeds are developed. The formulation is based on fundamental thermodynamics theories incorporated into an efficient preconditioning scheme in a unified manner. Local one-dimensional inviscid (LODI) relations compatible to the preconditioning system are proposed to obtain information carried by incoming characteristic waves at boundaries accurately. The approach has been validated against a variety of sample problems at a broad range of fluid states and flow speeds. Both acoustic waves and hydrodynamic flow features can pass through the boundaries of computational domain transparently without any un-physical reflection or spurious distortion. The approach can be reliably applied to fluid flows at extensive thermodynamic states and flow speeds in numerical simulations. Moreover, the use of the boundary condition shows to improve the computational efficiency.

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