V.S.Malyuga Numerical investigation of the flow in a duct with two serial stenoses. Algorithm of the solution |
Applied hydromechanics, Vol. 12 (84) ¹ 4, (2010) |
| A numerical solution algorithm for the unsteady incompressible Navier-Stokes equations is described in the paper. The discretization procedure is based on the finite volume method. The equations are solved in the fixed Cartesian coordinate system. Stabilized and bounded differencing schemes, second-order accurate in both space and time, are used. The TVD differencing scheme of Chakravarthy-Osher is employed for the discretization of the convective terms. The numerical algorithm is designed for three-dimensional arbitrarily unstructured meshes. The system of non-linear algebraic equations obtained from the discretization procedure is linearized and solved with the PISO algorithm. The corresponding systems of linear algebraic equations are solved using the iterative solvers based on the preconditioned conjugate/biconjugate gradient methods. These solvers are available from the repository NetLib [62]. The numerical algorithm described in the paper is employed for the direct numerical simulation of the flow in a duct containing two sequential stenoses. The calculations are performed for various widths of the inter-stenoses segment of the duct. It is established that if the duct is sufficiently narrow between the stenoses, in some range of Reynolds number, the vortices generated in the inter-stenoses domain are situated symmetrically. But if the duct is sufficiently wide between the stenoses, the two rows of the vortices generated in the inter-stenoses domain are chequer-wise situated. |
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KEY WORDS: numerical solution, finite volume method, solvers, stenos, vortices |
| TEXT LANGUAGE: Russian |