Direct Calculation of Entropy Generation by Solving Reynolds-Averaged Entropy Transport Equation in an Air-Cooled Turbine Cascade

Orhan, Omer Emre
Uzol, Oğuz
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 equations using a k-epsilon closure. Results show. that there could be significant differences especially in the spatial distributions of entropy fields. This type of approach could offer significant improvements in entropy and loss prediction in turbomachinery flows. However, more studies especially for accurate modeling of temperature fluctuations and temperature-velocity correlations in the entropy transport equation are needed.


Computation of multi-passage cascade flows with overset and deforming grids
Tuncer, İsmail Hakkı (null; 1997-12-01)
An overset grid method is applied to the solution of single and multi-passage cascade flows with a compressible Navier-Stokes solver. C-type grids around individual blades are overset onto a Cartesian background grid. Overset grids are allowed to move in time relative to each other as prescribed by the oscillatory plunging motion. The overset grid method uses a simple, robust numerical algorithm to localize moving boundary points and to interpolate solution variables across intergrid boundaries. Computation...
Numerical simulation of turbine internal cooling and conjugate heat transfer problems with Rans based turbulance models
Görgülü, İlhan; Akmandor, İbrahim Sinan; Department of Aerospace Engineering (2012)
The present study considers the numerical simulation of the different flow characteristics involved in the conjugate heat transfer analysis of an internally cooled gas turbine blade. Conjugate simulations require full coupling of convective heat transfer in fluid regions to the heat diffusion in solid regions. Therefore, accurate prediction of heat transfer quantities on both external and internal surfaces has the uppermost importance and highly connected with the performance of the employed turbulence mode...
Numerical Investigation of Nano-Cavities for Optimal Power Absorption in Solar Cells
Karaosmanoglu, Bariscan; Topcuoglu, Ulas; Tuygar, Emre; Ergül, Özgür Salih (2018-06-01)
We present a numerical study of nano-cavities used in solar cells for energy harvesting, by employing surface integral equations based on Maxwell's equations in the frequency domain and an efficient solver based on the multilevel fast multipole algorithm (MLFMA). With the three-dimensional modeling of surfaces, we obtain accurate results to evaluate the performances of different structures for improved power absorption in solar cells. This paper includes a brief description of the developed solver and initi...
Oeksuz, Oezhan; Akmandor, Ibrahim Sinan (2008-06-13)
In this paper, a new multiploid genetic optimization method handling surrogate models of the CID solutions is presented and applied for multi objective turbine blade aerodynamic optimization problem. A fast, efficient, robust, and automated design method is developed to aerodynamically optimize 3D gas turbine blades. The design objectives are selected as maximizing the adiabatic efficiency and torque so as to reduce the weight, size and cost of the gas turbine engine. A 3-Dimensional steady Reynolds Average...
3 D time accurate CFD simulations of wind turbine rotor flow fields
Tonkal, Ozan Çağrı; Pehlivan, Sercan; Sezer Uzol, Nilay; İşler, Veysi (American Institute of Aeronautics and Astronautics Inc.(AIAA); 2006-01-12)
This paper presents the results of three-dimensional and time-accurate Computational Fluid Dynamics (CFD) simulations of the flow field around the National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine rotor. The 3-D, unsteady, parallel, finite volume flow solver, PUMA2, is used for the simulations. The solutions are obtained using unstructured moving grids rotating with the turbine blades. Three different flow cases with different wind speeds and wind yaw angles are investigated:...
Citation Formats
O. E. Orhan and O. Uzol, “Direct Calculation of Entropy Generation by Solving Reynolds-Averaged Entropy Transport Equation in an Air-Cooled Turbine Cascade,” 2012, Accessed: 00, 2020. [Online]. Available: