scholarly journals Numerical Simulation of Combustion and Rotor-Stator Interaction in a Turbine Combustor

2003 ◽  
Vol 9 (5) ◽  
pp. 363-374 ◽  
Author(s):  
Dragos D. Isvoranu ◽  
Paul G. A. Cizmas
Keyword(s):  
Numerical Algorithm ◽  
Stokes Equations ◽  
Species Conservation ◽  
Finite Difference Approximation ◽  
Navier Stokes ◽  
Difference Approximation ◽  
Combustion Model ◽  
Combustion Gases ◽  
Fully Implicit ◽  
Correction Technique

This article presents the development of a numerical algorithm for the computation of flow and combustion in a turbine combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species-conservation equations. The chemistry model used herein is a two-step, global, finite-rate combustion model for methane and combustion gases. The governing equations are written in the strong conservation form and solved using a fully implicit, finite-difference approximation. The gas dynamics and chemistry equations are fully decoupled. A correction technique has been developed to enforce the conservation of mass fractions. The numerical algorithm developed herein has been used to investigate the flow and combustion in a one-stage turbine combustor.

The Influence of In Situ Reheat on Turbine-Combustor Performance

2004 ◽  
Author(s):  
Steven Chambers ◽  
Horia Flitan ◽  
Paul Cizmas ◽  
Dennis Bachovchin ◽  
Thomas Lippert ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Stokes Equations ◽  
Species Conservation ◽  
Navier Stokes ◽  
Combustion Model ◽  
Navier Stokes Equations ◽  
Blade Loading ◽  
Combustion Gases ◽  
Injection Parameters

This paper presents a numerical and experimental investigation of the in situ reheat necessary for the development of a turbine-combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species conservation equations. The chemistry model used herein is a two-step, global, finite rate combustion model for methane and combustion gases. A numerical simulation has been used to investigate the validity of the combustion model by comparing the numerical results against experimental data obtained for an isolated vane with fuel injection at its trailing edge. The numerical investigation has then been used to explore the unsteady transport phenomena in a four-stage turbine-combustor. In situ reheat simulations investigated the influence of various fuel injection parameters on power increase, airfoil temperature variation and turbine blade loading.

The Influence of In Situ Reheat on Turbine-Combustor Performance

2004 ◽  
Vol 128 (3) ◽  
pp. 560-572 ◽  
Author(s):  
Steven Chambers ◽  
Horia Flitan ◽  
Paul Cizmas ◽  
Dennis Bachovchin ◽  
Thomas Lippert ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Stokes Equations ◽  
Species Conservation ◽  
Navier Stokes ◽  
Combustion Model ◽  
Navier Stokes Equations ◽  
Blade Loading ◽  
Combustion Gases ◽  
Injection Parameters

This paper presents a numerical and experimental investigation of the in situ reheat necessary for the development of a turbine-combustor. The flow and combustion were modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species conservation equations. The chemistry model used herein was a two-step, global, finite rate combustion model for methane and combustion gases. A numerical simulation was used to investigate the validity of the combustion model by comparing the numerical results against experimental data obtained for an isolated vane with fuel injection at its trailing edge. The numerical investigation was then used to explore the unsteady transport phenomena in a four-stage turbine-combustor. In situ reheat simulations investigated the influence of various fuel injection parameters on power increase, airfoil temperature variation, and turbine blade loading. The in situ reheat decreased the power of the first stage, but increased more the power of the following stages, such that the power of the turbine increased between 2.8% and 5.1%, depending on the parameters of the fuel injection. The largest blade excitation in the turbine-combustor corresponded to the fourth-stage rotor, with or without combustion. In all cases analyzed, the highest excitation corresponded to the first blade passing frequency.

Potential Core of a Submerged Laminar Jet

1988 ◽  
Vol 110 (4) ◽  
pp. 392-398 ◽  
Author(s):  
Shiro Akaike ◽  
Mitsumasa Nemoto
Keyword(s):  
Numerical Solution ◽  
Flow Pattern ◽  
Stokes Equations ◽  
Finite Difference Approximation ◽  
Navier Stokes ◽  
Difference Approximation ◽  
Potential Core ◽  
Laminar Jet ◽  
Cone Type ◽  
Developing Region

This study is intended to clarify the flow pattern in the flow developing region of an axisymmetric laminar water jet issuing into the surrounding calm water. The jet, initially having a potential core region of some extent at the nozzle exit, was studied. The numerical solution of the Navier-Stokes equations in the developing region was obtained using a finite-difference approximation. The velocity profile was measured using a miniature cone-type hot probe. Flow visualization by the hydrogen bubble method was also performed. Experiments were carried out for the jet Reynolds number ranging from 100 to 600. The flow pattern in the developing region was made clear. The experimental results were compared with the numerical solution.

SCALING OF FLUID RECOVERY FROM PERCOLATION FRACTALS

Fractals ◽  
1994 ◽  
Vol 02 (02) ◽  
pp. 269-272 ◽  
Author(s):  
IAN D WEDGWOOD ◽  
DONALD M MONRO
Keyword(s):  
Stokes Equations ◽  
Petroleum Reservoirs ◽  
Finite Difference Approximation ◽  
Navier Stokes ◽  
Difference Approximation ◽  
Viscous Effects ◽  
Navier Stokes Equation ◽  
Navier Stokes Equations ◽  
Reservoir Models ◽  
Wide Range

We report on the recovery of fluid driven through percolation lattices across a range of scales using a finite difference approximation to the Navier-Stokes equation. This is important in the study of recovery from petroleum reservoirs, in which flow occurs over a wide range of scales, from the microscopic pores right up to the full reservoir. This variation of scale presents difficulties, since flow at the pore level is subject to predominantly viscous effects, whereas at the larger scales the viscous effects may become negligible in comparison with inertial effects. The Navier-Stokes equations may differ greatly with scale. Theoretical rock structures are created using percolation lattices and the flow properties of identical rock structures are then examined as a function of scale. The resultant recovery rates exhibit similarity across scale which would simplify the study of geological reservoir models.

scholarly journals Numerical Solution of the Navier–Stokes Equations Using Multigrid Methods with HSS-Based and STS-Based Smoothers

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 233
Author(s):  
Galina Muratova ◽  
Tatiana Martynova ◽  
Evgeniya Andreeva ◽  
Vadim Bavin ◽  
Zeng-Qi Wang
Keyword(s):  
Stokes Equations ◽  
Hermitian Matrix ◽  
Multigrid Methods ◽  
Finite Difference Approximation ◽  
Navier Stokes ◽  
Difference Approximation ◽  
Algebraic Equations ◽  
Navier Stokes Equations ◽  
Linear Algebraic Equations ◽  
Discretized Systems

Multigrid methods (MGMs) are used for discretized systems of partial differential equations (PDEs) which arise from finite difference approximation of the incompressible Navier–Stokes equations. After discretization and linearization of the equations, systems of linear algebraic equations (SLAEs) with a strongly non-Hermitian matrix appear. Hermitian/skew-Hermitian splitting (HSS) and skew-Hermitian triangular splitting (STS) methods are considered as smoothers in the MGM for solving the SLAE. Numerical results for an algebraic multigrid (AMG) method with HSS-based smoothers are presented.

Parallel CUDA implementation of a numerical algorithm for solving the Navier-Stokes equations using the pressure uniqueness condition

2021 ◽  
Author(s):  
Almas Temirbekov ◽  
Dossan Baigereyev ◽  
Nurlan Temirbekov ◽  
Baidaulet Urmashev ◽  
Aidana Amantayeva
Keyword(s):  
Numerical Algorithm ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Uniqueness Condition ◽  
Navier Stokes Equations

scholarly journals Modeling of Tip Clearance Flows Through an Improved 3-D Pressure Correction Navier-Stokes Solver

1993 ◽  
Author(s):  
N. Lymberopoulos ◽  
K. Giannakoglou ◽  
I. Nikolaou ◽  
K. D. Papailiou ◽  
A. Tourlidakis ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Special Treatment ◽  
Pressure Correction ◽  
Compressor Rotor ◽  
Numerical Predictions ◽  
Correction Technique

Mechanical constraints dictate the existence of tip clearances in rotating cascades, resulting to a flow leakage through this clearance which considerably influences the efficiency and range of operation of the machine. Three-dimensional Navier-Stokes solvers are often used for the numerical study of compressor and turbine stages with tip-clearance. The quality of numerical predictions depends strongly on how accurately the blade tip region is modelled; in this respect the accurate modelling of tip region was one of the main goals of this work. In the present paper, a 3-D Navier-Stokes solver is suitably adapted so that the flat tip surface of a blade and its sharp edges could be accurately modelled, in order to improve the precision of the calculation in the tip region. The adapted code solves the fully elliptic, steady, Navier-Stokes equations through a space-marching algorithm and a pressure correction technique; the H-type topology is retained, even in cases with thick leading edges where a special treatment is introduced herein. The analysis is applied to two different cases, a linear cascade and a compressor rotor, and comparisons with experimental data are provided.

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