Transient simulation of internal separated flows using an intelligent higher-order spatial discretization scheme

1997-04-30
Oymak, O
Selçuk, Nevin
This paper summarizes the method-of-lines (MOL) solution of the Navier-Stokes equations for an impulsively started incompressible laminar flow in a circular pipe with a sudden expansion. An intelligent higher-order spatial discretization scheme, which chooses upwind or downwind discretization in a zone-of-dependence manner when flow reversal occurs, was developed for separated flows. Stability characteristics of a linear advective-diffusive equation were examined to depict the necessity of such a scheme in the case of flow reversals. The proposed code was applied to predict the time development of an impulsively started flow in a pipe with a sudden expansion. Predictions were found to show the expected trends for both unsteady and steady states. This paper demonstrates the ease with which the Navier-Stokes equations can be solved in an accurate manner using sophisticated numerical algorithms for the solution of ordinary differential equations (ODEs). Solutions of the Navier-Stokes equations in primitive variables formulation by using the MOL and intelligent higher-order spatial discretization scheme are not available to date. (C) 1997 by John Wiley & Sons, Ltd.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS

Suggestions

Intrusive and data-driven reduced order modelling of the rotating thermal shallow water equation
Yıldız, Süleyman; Karasözen, Bülent; Uzunca, Murat (2022-05-15)
In this paper, we investigate projection-based intrusive and data-driven model order reduction in numerical simulation of rotating thermal shallow water equation (RTSWE) in parametric and non-parametric form. Discretization of the RTSWE in space with centered finite differences leads to Hamiltonian system of ordinary differential equations with linear and quadratic terms. The full-order model (FOM) is obtained by applying linearly implicit Kahan's method in time. Applying proper orthogonal decomposition wit...
Implicit lattice boltzmann method for laminar/turbulent flows
Çevik, Fatih; Albayrak, Kahraman; Department of Mechanical Engineering (2016)
Lattice Boltzmann Method is an alternative computational method for fluid physics problems. The development of the method started in the late 1980s and early 1990s. Various numerical schemes like stream and collide, finite difference, finite element and finite volume schemes are used to solve the discrete Lattice Boltzmann Equation. Almost all of the numerical schemes in the literature are explicit schemes to exploit the natural features of the discrete Lattice Boltzmann Equation like parallelism and easy c...
Numerical simulation of transient turbulent flow in a heated pipe
Uygur, Ahmet Bilge; Selçuk, Nevin; Oymak, Olcay; Department of Chemical Engineering (2002)
A computational fluid dynamics (CFD) code based on direct numerical simulation (DNS) and the method of lines MOL approach developed previously for the solution of transient two-dimensional Navier-Stokes equations for turbulent, incompressible, internal, non-isothermal flows with constant wall temperature was applied to prediction of turbulent flow and temperature fields in flows dominated by forced convection in circular tubes with strong heating. Predictive ability of the code was tested by comparing its r...
Direct Calculation of Entropy Generation by Solving Reynolds-Averaged Entropy Transport Equation in an Air-Cooled Turbine Cascade
Orhan, Omer Emre; Uzol, Oğuz (2012-06-15)
This paper presents an implementation of directly solving Reynolds-Averaged Entropy Transport equation as a part of the CFD solution to predict entropy generation rates in a two-dimensional turbine blade stator section. The Reynolds Averaged Entropy Transport and the necessary modeling. equations are implemented to a commercial CFD solver as a User Defined Scalar (UDS). The results are compared with those obtained by post-processing the temperature and velocity fields obtained by solving full Navier-Stokes ...
Analytical solution of thermally developing microtube heat transfer including axial conduction, viscous dissipation, and rarefaction effects
Barışık, Murat; Yazıcıoğlu, Almıla Güvenç; Çetin, Barbaros; Kakaç, Sadık (Elsevier BV, 2015-10)
The solution of extended Graetz problem for micro-scale gas flows is performed by coupling of rarefaction, axial conduction and viscous dissipation at slip flow regime. The analytical coupling achieved by using Gram-Schmidt orthogonalization technique provides interrelated appearance of corresponding effects through the variation of non-dimensional numbers. The developing temperature field is determined by solving the energy equation locally together with the fully developed flow profile. Analytical solutio...
Citation Formats
O. Oymak and N. Selçuk, “Transient simulation of internal separated flows using an intelligent higher-order spatial discretization scheme,” INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, pp. 759–769, 1997, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54857.