Numerical simulation of transient turbulent flow in a heated pipe

Uygur, Ahmet Bilge
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 results with experimental data available in iiithe literature for air flowing upward in a vertical tube with heating rates causing significant property variation. Two entry Reynolds numbers were employed, with three different heating rates yielding conditions considered to be turbulent, sub- turbulent and laminarizing. Favorable comparisons were obtained between the predictions and measurements. Small discrepancies in the near wall region can be attributed to strong heating which induces significant variations of the gas properties. In an attempt to improve the performance of the code, a parallel algorithm of the code was developed and tested against sequential code for speed-up and efficiency. It was found that the same results are obtained with super-linear speed-up and efficiency. The code provides an algorithm for future DNS applications.


Mol solution for transient turbulent flow in a heated pipe
Uygur, AB; Tarhan, T; Selçuk, Nevin (2005-08-01)
A computational fluid dynamics (CFD) code, based on direct numerical simulation (DNS) and method of lines (MOL) approach previously developed for the prediction of transient turbulent, incompressible, confined non-isothermal flows with constant wall temperature was applied to the prediction of turbulent flow and temperature fields in flows dominated by forced convection in circular tubes with strong heating. The code was parallelized in order to meet the high grid resolutions required by DNS of turbulent fl...
Transient simulation of radiating flows
Selçuk, Nevin; Ayranci, I; Tarhan, T (2005-06-01)
Time-dependent Navier-Stokes equations are solved in conjunction with the radiative transfer equation by coupling a previously developed direct numerical simulation-based computational fluid dynamics code to an existing radiation code, both based on the method of lines approach. The temperature profiles predicted by the coupled code are validated against steady-state solutions available in the literature for laminar, axisymmetric, hydrodynamically developed flow of a gray, absorbing, emitting fluid in a hea...
Kirez, Oguz; Güvenç Yazıcıoğlu, Almıla; KAKAÇ, SADIK (2012-11-15)
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Transient simulation of reacting radiating flows
Uygur, A. Bilge; Tarhan, Tanil; Selçuk, Nevin (2006-10-01)
Laminar methane-air diffusion flame was simulated by coupling a method of lines based parallel direct numerical simulation code with a radiation code based on method of lines solution of discrete ordinates method. The predictions of the code are validated against experimental data as well as numerical results of the same code without radiation model. Comparisons show that incorporation of radiation code to the computational fluid dynamics code results in a significant improvement in the predicted temperatur...
Numerical Simulation of Reciprocating Flow Forced Convection in Two-Dimensional Channels
Sert, Cüneyt (ASME International, 2003-5-20)
<jats:p>Numerical simulations of laminar, forced convection heat transfer for reciprocating, two-dimensional channel flows are performed as a function of the penetration length, Womersley (α) and Prandtl (Pr) numbers. The numerical algorithm is based on a spectral element formulation, which enables high-order spatial resolution with exponential decay of discretization errors, and second-order time-accuracy. Uniform heat flux and constant temperature boundary conditions are imposed on certain regions of the ...
Citation Formats
A. B. Uygur, “Numerical simulation of transient turbulent flow in a heated pipe,” Middle East Technical University, 2002.