scholarly journals The Extension of a Solution-Adaptive 3D Navier-Stokes Solver Towards Geometries of Arbitrary Complexity

1992 ◽  
Author(s):  
W. N. Dawes
Keyword(s):  
Guide Vane ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Wide Range ◽  
Nozzle Guide Vane ◽  
Arbitrary Geometries ◽  
Recent Developments ◽  
Nozzle Guide

This paper describes recent developments to a three dimensional, unstructured mesh, solution-adaptive Navier-Stokes solver. By adopting a simple, pragmatic but systematic approach to mesh generation, the range of simulations which can be attempted is extended towards arbitrary geometries. The combined benefits of the approach result in a powerful analytical ability. Solutions for a wide range of flows are presented including a transonic compressor rotor, a centrifugal impellor, a steam turbine nozzle guide vane with casing extraction belt, the internal coolant passage of a radial inflow turbine and a turbine disc-cavity flow.

The Extension of a Solution-Adaptive Three-Dimensional Navier–Stokes Solver Toward Geometries of Arbitrary Complexity

1993 ◽  
Vol 115 (2) ◽  
pp. 283-295 ◽  
Author(s):  
W. N. Dawes
Keyword(s):  
Guide Vane ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Wide Range ◽  
Nozzle Guide Vane ◽  
Recent Developments ◽  
Nozzle Guide

This paper describes recent developments to a three-dimensional, unstructured mesh, solution-adaptive Navier–Stokes solver. By adopting a simple, pragmatic but systematic approach to mesh generation, the range of simulations that can be attempted is extended toward arbitrary geometries. The combined benefits of the approach result in a powerful analytical ability. Solutions for a wide range of flows are presented, including a transonic compressor rotor, a centrifugal impeller, a steam turbine nozzle guide vane with casing extraction belt, the internal coolant passage of a radial inflow turbine, and a turbine disk cavity flow.

Toward Improved Throughflow Capability: The Use of Three-Dimensional Viscous Flow Solvers in a Multistage Environment

1992 ◽  
Vol 114 (1) ◽  
pp. 8-17 ◽  
Author(s):  
W. N. Dawes
Keyword(s):  
Experimental Evidence ◽  
Guide Vane ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Flow Properties ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

A methodology is presented for simulating turbomachinery blade rows in a multistage environment by deploying a standard three-dimensional Navier–Stokes solver simultaneously on a number of blade rows. The principal assumptions are that the flow is steady relative to each blade row individually and that the rows can communicate via inter-row mixing planes. These mixing planes introduce circumferential averaging of flow properties but preserve quite general radial variations. Additionally, each blade can be simulated in three-dimensional or axisymmetrically (in the spirit of throughflow analysis) and a series of axisymmetric rows can be considered together with one three-dimensional row to provide, cheaply, a machine environment for that row. Two applications are presented: a transonic compressor rotor and a steam turbine nozzle guide vane simulated both isolated and as part of a stage. In both cases the behavior of the blade considered in isolation was different to when considered as part of a stage and in both cases was in much closer agreement with the experimental evidence.

Towards Improved Throughflow Capability: The Use of 3D Viscous Flow Solvers in a Multistage Environment

1990 ◽  
Author(s):  
W. N. Dawes
Keyword(s):  
Experimental Evidence ◽  
Steam Turbine ◽  
Guide Vane ◽  
Navier Stokes ◽  
Flow Properties ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

A methodology is presented for simulating turbomachinery blade rows in a multistage environment by deploying a standard 3D Navier-Stokes solver simultaneously on a number of blade rows. The principle assumptions are that the flow is steady relative to each blade row individually and that the rows can communicate via inter-row mixing planes. These mixing planes introduce circumferential averaging of flow properties but preserve quite general radial variations. Additionally, each blade can be simulated in 3D or axisymmetrically (in the spirit of throughflow analysis) and a series of axisymmetric rows can be considered together with one 3D row to provide, cheaply, a machine environment for that row. Two applications are presented: a transonic compressor rotor and a steam turbine nozzle guide vane simulated both isolated and as part of a stage. In both cases the behaviour of the blade considered in isolation was different to when considered as part of a stage and in both cases was in much closer agreement with the experimental evidence.

Influence of Pre-History and Leading Edge Contouring on Aero-Performance of a 3D Nozzle Guide Vane

2013 ◽  
Author(s):  
Ranjan Saha ◽  
Boris I. Mamaev ◽  
Jens Fridh ◽  
Björn Laumert ◽  
Torsten H. Fransson
Keyword(s):  
Guide Vane ◽  
Three Dimensional ◽  
Leading Edge ◽  
Stagnation Line ◽  
Wide Range ◽  
Nozzle Guide Vane ◽  
Turbine Vane ◽  
Loss Coefficients ◽  
Exit Mach Number ◽  
Nozzle Guide

Experiments are conducted to investigate the effect of the pre-history in the aerodynamic performance of a three-dimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (5 hole and 3 hole) concentrating mainly on the endwall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector and vorticity contour, as well as, mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the pre-history (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface which allows identifying the locations of secondary flow vortices, stagnation line and saddle point.

Influence of Prehistory and Leading Edge Contouring on Aero Performance of a Three-Dimensional Nozzle Guide Vane

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Ranjan Saha ◽  
Boris I. Mamaev ◽  
Jens Fridh ◽  
Björn Laumert ◽  
Torsten H. Fransson
Keyword(s):  
Guide Vane ◽  
Three Dimensional ◽  
Leading Edge ◽  
Stagnation Line ◽  
Wide Range ◽  
Nozzle Guide Vane ◽  
Loss Coefficients ◽  
Exit Mach Number ◽  
Nozzle Guide ◽  
End Wall

Experiments are conducted to investigate the effect of the prehistory in the aerodynamic performance of a three-dimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (five hole and three hole) concentrating mainly on the end wall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector, and vorticity contour, as well as mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the prehistory (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface, which allows identifying the locations of secondary flow vortices, stagnation line, and saddle point.

Effects of Gap Leakage on Fluid Flow in a Contoured Turbine Nozzle Guide Vane

2000 ◽  
Author(s):  
Y.-L. Lin ◽  
T. I-P. Shih ◽  
M. K. Chyu ◽  
R. S. Bunker
Keyword(s):  
Computational Study ◽  
Guide Vane ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Hot Gas ◽  
Nozzle Guide Vane ◽  
A Cell ◽  
Nozzle Guide ◽  
Volume Method

Computations were performed to study the three-dimensional flow in a nozzle guide vane with leakage issuing from a narrow gap with a backward-facing step located upstream of the airfoil on each endwall. The nozzle guide vane investigated has one flat and one contoured endwall. For the contoured endwall, two configurations of the same contouring profile were investigated with and without gap leakage. In one configuration, all contouring is upstream of the airfoil passage. In the other, the contouring starts upstream of the airfoil passage and continues through it. Results obtained show that when there is gap leakage, secondary flows are reduced at all endwalls for both nozzle configurations investigated. Without gap leakage, secondary flows are reduced only on the contoured endwall in which the contouring started upstream of the airfoil passage and continued through it. When all of the contouring is located upstream of the airfoil passage, there is considerable hot gas ingestion into the gap at both endwalls. When the contouring starts upstream of the airfoil passage and continues throught it, hot gas ingestion was minimal at the contoured endwall and greatly reduced at the flat endwall. This computational study is based on the ensemble-averaged conservation equations of mass, momentum (compressible Navier-Stokes), and energy. Effects of turbulence were modeled by the low Reynolds number shear-stress transport k-ω model. Solutions were generated by a cell-centered finite-volume method that uses third-order accurate flux-difference splitting of Roe with limiters and multigrid acceleration of a diagonalized ADI scheme with local time stepping on patched structured grids.

Control of Secondary Flows in a Turbine Nozzle Guide Vane by Endwall Contouring

2000 ◽  
Author(s):  
T. I-P. Shih ◽  
Y.-L. Lin ◽  
T. W. Simon
Keyword(s):  
Film Cooling ◽  
Computational Study ◽  
Guide Vane ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Film Cooling Effectiveness ◽  
Nozzle Guide Vane ◽  
A Cell ◽  
Nozzle Guide

Computations were performed to study the three-dimensional flow and temperature distribution in a nozzle guide vane that has one flat and one contoured endwall with and without film cooling injected from two slots, one on each endwall located just upstream of the airfoil. For the contoured endwall, two locations of the same contouring were investigated, one with all contouring upstream of the airfoil and another with the contouring starting upstream of the airfoil and continuing through the airfoil passage. Results obtained show that when the contouring is all upstream of the airfoil, secondary flows on both the flat and the contoured endwalls are similar in magnitude. When the contouring starts upstream of the airfoil and continues through the airfoil passage, secondary flows on the contoured endwall are markedly weaker than those on the flat endwall. With weaker secondary flows on the contoured endwall, film-cooling effectiveness there is greatly improved. This computational study is based on the ensemble-averaged conservation equations of mass, momentum (compressible Navier-Stokes), and energy. Effects of turbulence were modeled by the low Reynolds number shear-stress transport k-ω model. Solutions were generated by a cell-centered, finite-volume method that uses third-order accurate flux-difference splitting of Roe with limiters and multigrid acceleration of a diagonalized ADI scheme with local time stepping on patched/embedded structured grids.

Shape Optimization of Transonic Compressor Blades Using Quasi-3D Flow Physics

2000 ◽  
Author(s):  
June Chung ◽  
Ki D. Lee
Keyword(s):  
Design Method ◽  
Computational Cost ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Navier Stokes ◽  
Compressor Blades ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Wide Range

A design method for transonic compressor rotor blades is developed based on Navier-Stokes physics. The method is applied to optimize the blade sections at several span stations, and new three-dimensional blades are constructed by interpolating the geometry of the designed blade sections. The method is demonstrated with NASA Rotor 37, producing new rotor blades with improved adiabatic efficiency over a wide range of operating conditions. The results indicate that the developed design process can find improved designs at an affordable computational cost.

Flow Field Unsteadiness in the Tip Region of a Transonic Compressor Rotor

1997 ◽  
Vol 119 (1) ◽  
pp. 122-128 ◽  
Author(s):  
S. L. Puterbaugh ◽  
W. W. Copenhaver
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Vortex Interaction ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Operating Points

An experimental investigation concerning tip flow field unsteadiness was performed for a high-performance, state-of-the-art transonic compressor rotor. Casing-mounted high frequency response pressure transducers were used to indicate both the ensemble averaged and time varying flow structure present in the tip region of the rotor at four different operating points at design speed. The ensemble averaged information revealed the shock structure as it evolved from a dual shock system at open throttle to an attached shock at peak efficiency to a detached orientation at near stall. Steady three-dimensional Navier Stokes analysis reveals the dominant flow structures in the tip region in support of the ensemble averaged measurements. A tip leakage vortex is evident at all operating points as regions of low static pressure and appears in the same location as the vortex found in the numerical solution. An unsteadiness parameter was calculated to quantify the unsteadiness in the tip cascade plane. In general, regions of peak unsteadiness appear near shocks and in the area interpreted as the shock-tip leakage vortex interaction. Local peaks of unsteadiness appear in mid-passage downstream of the shock-vortex interaction. Flow field features not evident in the ensemble averaged data are examined via a Navier-Stokes solution obtained at the near stall operating point.

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