Numerical Investigations on the Optimum Design of Radial Inflow Turbine Guide Vanes

1994 ◽  
Author(s):  
A. W. Reichert ◽  
H. Simon
Keyword(s):  
High Efficiency ◽  
Stokes Equations ◽  
Guide Vane ◽  
Iterative Solution ◽  
Design Principles ◽  
Solution Procedure ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Guide Vanes ◽  
Standard Interface

To improve the prediction of compressible flow in highly loaded turbomachinery components a modified high resolution scheme to solve the Navier Stokes equations has been developed. The scheme is based on the methods introduced by Osher and Roe. For high efficiency, an implicit iterative solution procedure is used. The code is validated, presenting highly accurate computational results. A structured grid is used during the investigations and a special grid topology for turbine vanes is presented. As the guide vanes are designed using CAD software the CFD code is coupled via the standard interface IGES (Smith et al., 1988). Starting with classical design principles, a first guide vane is designed. Based on flow field computations, the design of the guide vanes is improved successively. Resulting from the experiences gained during the improvement procedure general design principles are formulated.

The Effect of Midplane Guide Vanes in a Biplane Wells Turbine

2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Tapas K. Das ◽  
Abdus Samad
Keyword(s):  
Stokes Equations ◽  
Guide Vane ◽  
Flow Analysis ◽  
Leading Edge ◽  
Navier Stokes ◽  
Flow Conditions ◽  
Wells Turbine ◽  
Navier Stokes Equations ◽  
Guide Vanes ◽  
Ansys Cfx

Guide vanes (GVs) improve the performance of a turbine in terms of efficiency, torque, or operating range. In this work, a concept of different orientations of GVs in between a two-row biplane wells turbine (BWT) was introduced and analyzed for the performance improvement. The fluid flow was simulated numerically with a commercial software ANSYS CFX 16.1. The Reynolds-averaged Navier–Stokes equations with the k-ω turbulence closure model were solved for different designs and flow conditions. For the base model, the results from simulation and experiments are in close agreement. Among the designs considered, the configuration, where the blades are in one line (zero circumferential angle between blades of two plane) and the midplane guide vane has concave side to the leading edge of the blade, performed relatively better. However, the performance was still less compared to the base model. The reason behind the reduction in performance from the base model is attributed to the blockage of flow and the change of flow path occurring due to the presence of the midplane GVs. The flow analysis of different cases and the comparison with the base model are presented in the current study.

Measurement and Calculation of Nozzle Guide Vane End Wall Heat Transfer

1998 ◽  
Author(s):  
Neil W. Harvey ◽  
Martin G. Rose ◽  
John Coupland ◽  
Terry Jones
Keyword(s):  
Heat Transfer ◽  
Stokes Equations ◽  
Guide Vane ◽  
Correction Method ◽  
Navier Stokes ◽  
Design Data ◽  
Navier Stokes Equations ◽  
Wall Functions ◽  
Transfer Rates ◽  
Nozzle Guide

A 3-D steady viscous finite volume pressure correction method for the solution of the Reynolds averaged Navier-Stokes equations has been used to calculate the heat transfer rates on the end walls of a modern High Pressure Turbine first stage stator. Surface heat transfer rates have been calculated at three conditions and compared with measurements made on a model of the vane tested in annular cascade in the Isentropic Light Piston Facility at DERA, Pyestock. The NGV Mach numbers, Reynolds numbers and geometry are fully representative of engine conditions. Design condition data has previously been presented by Harvey and Jones (1990). Off-design data is presented here for the first time. In the areas of highest heat transfer the calculated heat transfer rates are shown to be within 20% of the measured values at all three conditions. Particular emphasis is placed on the use of wall functions in the calculations with which relatively coarse grids (of around 140,000 nodes) can be used to keep computational run times sufficiently low for engine design purposes.

Numerical Modeling of Flow Over a Dam Spillway

2006 ◽  
Author(s):  
Iraj Saeedpanah ◽  
M. Shayanfar ◽  
E. Jabbari ◽  
Mohammad Haji Mohammadi
Keyword(s):  
Free Surface ◽  
Stokes Equations ◽  
Iterative Solution ◽  
Free Surface Flows ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Continuity Equations ◽  
Water Jets ◽  
Pressure Fields ◽  
Good Agreement

Free surface flows are frequently encountered in hydraulic engineering problems including water jets, weirs and around gates. An iterative solution to the incompressible two-dimensional vertical steady Navier-Stokes equations, comprising momentum and continuity equations, is used to solve for the priori unknown free surface, the velocity and the pressure fields. The entire water body is covered by a unstructured finite element grid which is locally refined. The dynamic boundary condition is imposed for the free surface where the pressure vanishes. This procedure is done continuously until the normal velocities components vanish. To overcome numerical errors and oscillations encountering in convection terms, the SUPG (streamline upwinding Petrov-Galerkin) method is applied. The solution method is tested for different discharges onto a standard spillway geometries. The results shows good agreement with available experimental data.

scholarly journals Aerothermodynamic Effects and Modeling of the Tangential Curvature of Guide Vanes in an Axial Turbine Stage

2017 ◽  
Vol 2017 ◽  
pp. 1-16
Author(s):  
Tzong-Hann Shieh
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Suction Side ◽  
Meridional Flow ◽  
Navier Stokes ◽  
Obtuse Angle ◽  
Turbine Stage ◽  
Navier Stokes Equations ◽  
Axial Turbine ◽  
Guide Vanes

By tangential curvature of the stacking line of the profiles guide vanes can be designed, which have on both ends an obtuse angle between suction side and sidewall. This configuration, according to literature, is capable of reducing secondary loss. This type of vanes develops considerable radial components of the blade force and effects a displacement of the meridional flow towards both sidewalls. In this paper we work with a finite-volume-code for computations of the three-dimensional Reynolds averaged Navier-Stokes equations for an axial turbine stage with radial and two types of tangentially curved guide vanes. With computational results, mathematical formulations are developed for a new flow model of deflection of such blades that are formally compatible with the assumption of a rotation-symmetrical flow and with the existing throughflow codes, in order to predict the deflection angle over the blade height for the tangential leaned and curved blades.

IGV-Rotor Interaction Analysis in a Transonic Compressor Using the Navier-Stokes Equations

1996 ◽  
Author(s):  
Andrea Arnone ◽  
Roberto Pacciani
Keyword(s):  
Stokes Equations ◽  
Interaction Analysis ◽  
Guide Vane ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Inlet Guide Vane ◽  
Operating Characteristics ◽  
Navier Stokes Equations ◽  
Transonic Compressor ◽  
Mass Flow Rates

A recently developed, time-accurate multigrid viscous solver has been extended to handle quasi-three-dimensional effects and applied to the first stage of a modern transonic compressor. Interest is focused on the inlet guide vane (IGV):rotor interaction where strong sources of unsteadiness are to be expected. Several calculations have been performed to predict the stage operating characteristics. Flow structures at various mass flow rates, from choke to near stall, are presented and discussed. Comparisons between unsteady and steady pitch-averaged results are also included in order to obtain indications about the capabilities of steady, multi-row analyses.

Numerical Simulation of Asymmetric Exhaust Flows Using an Actuator Disc Blade Row Model

2002 ◽  
Author(s):  
Jianjun Liu
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Solution Procedure ◽  
Navier Stokes ◽  
Exhaust Hood ◽  
Navier Stokes Equations ◽  
Multigrid Algorithm ◽  
Blade Row ◽  
Actuator Disc

This paper describes the numerical simulation of the asymmetric exhaust flows by using a 3D viscous flow solver incorporating an actuator disc blade row model. The three dimensional Reynolds-Averaged Navier-Stokes equations are solved by using the TVD Lax-Wendroff scheme. The convergence to a steady state is speeded up by using the V-cycle multigrid algorithm. Turbulence eddy viscosity is estimated by the Baldwin-Lomax model. Multiblock method is applied to cope with the complicated physical domains. Actuator disc model is used to represent a turbine blade row and to achieve the required flow turning and entropy rise across the blade row. The solution procedure and the actuator disc boundary conditions are described. The stream traces in various sections of the exhaust hood are presented to demonstrate the complicity of the flow patterns existing in the exhaust hood.

Flow past a row of flat plates at large Reynolds numbers

1993 ◽  
Vol 441 (1912) ◽  
pp. 211-235 ◽  
Keyword(s):  
Stokes Equations ◽  
Solution Procedure ◽  
Circular Cylinders ◽  
Navier Stokes ◽  
Flat Plates ◽  
Navier Stokes Equations ◽  
Element Discretization ◽  
Flow Past ◽  
High Reynolds ◽  
Outflow Boundary

The steady, incompressible, high Reynolds number, viscous flow past a row of flat plates is computed by a Galerkin finite element discretization of the Navier-Stokes equations in the streamfunction/vorticity formulation. A novel implementation of the inflow and outflow boundary conditions is described, which combines numerical stability with computational economy in the solution procedure. The calculations reported here cover the range of medium and small blockage ratios, i. e. 5 ≼ a ≼ 25 (where a is the inverse blockage ratio). A transition is found from narrow wake eddies for small values of a , to wide wake eddies for values of a above a crit ≈ 15. This transition is in general agreement with the trends reported earlier by Fornberg (1991), for the related problem of flow past a row of circular cylinders (for which a crit was approximately 8).

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