scholarly journals A Three-Dimensional Turbine Engine Analysis Compressor Code (TEACC) for Steady-State Inlet Distortion

1997 ◽  
Author(s):  
Alan Hale ◽  
Walter O’Brien
Keyword(s):  
Three Dimensional ◽  
Simulation Tool ◽  
Source Terms ◽  
Turbine Engine ◽  
Streamline Curvature ◽  
Inlet Distortion ◽  
Blade Row ◽  
Practical Design ◽  
Distorted Region ◽  
Computationally Intensive

The direct approach of modeling the flow between all blade passages for each blade row in the compressor is too computationally intensive for practical design and analysis investigations with inlet distortion. Therefore a new simulation tool called the Turbine Engine Analysis Compressor Code (TEACC) has been developed. TEACC solves the compressible, time-dependent, 3D Euler equations modified to include turbomachinery source terms which represent the effect of the blades. The source terms are calculated for each blade row by the application of a streamline curvature code. TEACC was validated against experimental data from the transonic NASA rotor, Rotor 1B, for a clean inlet and for an inlet distortion produced by a 90-deg, one-per-revolution distortion screen. TEACC revealed that strong swirl produced by the rotor caused the compressor to increase in loading in the direction of rotor rotation through the distorted region and decrease in loading circumferentially away from the distorted region.

1997 Best Paper Award—Education Committee: A Three-Dimensional Turbine Engine Analysis Compressor Code (TEACC) for Steady-State Inlet Distortion

1998 ◽  
Vol 120 (3) ◽  
pp. 422-430 ◽  
Author(s):  
A. Hale ◽  
W. O’Brien
Keyword(s):  
Three Dimensional ◽  
Simulation Tool ◽  
Source Terms ◽  
Turbine Engine ◽  
Streamline Curvature ◽  
Inlet Distortion ◽  
Blade Row ◽  
Practical Design ◽  
Distorted Region ◽  
Computationally Intensive

The direct approach of modeling the flow between all blade passages for each blade row in the compressor is too computationally intensive for practical design and analysis investigations with inlet distortion. Therefore a new simulation tool called the Turbine Engine Analysis Compressor Code (TEACC) has been developed. TEACC solves the compressible, time-dependent, three-dimensional Euler equations modified to include turbomachinery source terms, which represent the effect of the blades. The source terms are calculated for each blade row by the application of a streamline curvature code. TEACC was validated against experimental data from the transonic NASA rotor, Rotor 1B, for a clean inlet and for an inlet distortion produced by a 90-deg, one-per-revolution distortion screen. TEACC revealed that strong swirl produced by the rotor caused the compressor to increase in loading in the direction of rotor rotation through the distorted region and decrease in loading circumferentially away from the distorted region.

scholarly journals Through-Flow Analysis for Axial-Stage Design Including Streamline-Slope Effects

1993 ◽  
Author(s):  
Theodosios Korakianitis ◽  
Dequan Zou
Keyword(s):  
Mass Flow ◽  
Three Dimensional ◽  
Momentum Equation ◽  
Total Enthalpy ◽  
Streamline Curvature ◽  
Flow Balance ◽  
Through Flow ◽  
Blade Row ◽  
Iteration Loop ◽  
Predictor Corrector

This paper presents a new method to design (or analyze) subsonic or supersonic axial compressor and turbine stages and their three-dimensional velocity diagrams from hub to tip by solving the three-dimensional radial-momentum equation. Some previous methods (matrix through-flow based on the streamfunction approach) can not handle locally supersonic flows, and they are computationally intensive when they require the inversion of large matrices. Other previous methods (streamline curvature) require two nested iteration loops to provide a converged solution: an outside iteration loop for the mass-flow balance; and an inside iteration loop to solve the radial momentum equation at each flow station. The present method is of the streamline-curvature category. It still requires the iteration loop for the mass-flow balance, but the radial momentum equation at each flow station is solved using a one-pass numerical predictor-corrector technique, thus reducing the computational effort substantially. The method takes into account the axial slope of the streamlines. Main design characteristics such as the mass-flow rate, total properties at component inlet, hub-to-tip ratio at component inlet, total enthalpy change for each stage, and the expected efficiency of each streamline at each stage are inputs to the method. Other inputs are the radial position and axial velocity component at one surface of revolution through the axial stages. These can be provided for either the hub, or the mean, or the tip location of the blading. In addition the user specifies the azimuthal deflection of the flow from the axial direction at each radius (or as a function of radius) at each blade row inlet and outlet. By construction the method eliminates radial variations of total enthalpy (work) and entropy at each blade row inlet and outlet. In an alternative formulation enthalpy variations across radial positions at each axial station are included in the analysis. The remaining three-dimensional velocity diagrams from hub to tip, and the radial location of the remaining streamlines, are obtained by solving the momentum equation using a predictor-corrector method. Examples for one turbine and one compressor design are included.

A Quasi-Three-Dimensional Turbomachinery Blade Design System: Part I—Throughflow Analysis

1985 ◽  
Vol 107 (2) ◽  
pp. 301-307 ◽  
Author(s):  
I. K. Jennions ◽  
P. Stow
Keyword(s):  
Three Dimensional ◽  
Computing System ◽  
Design System ◽  
Blade Design ◽  
Weighted Averages ◽  
Streamline Curvature ◽  
Blade Row ◽  
Blade Section ◽  
System Part ◽  
Analysis System

The purpose of this work has been to develop a quasi-three-dimensional blade design and analysis system incorporating fully linked throughflow, blade-to-blade and blade section stacking programs. In Part I of the paper, the throughflow analysis is developed. This is based on a rigorous passage averaging technique to derive throughflow equations valid inside a blade row. The advantages of this approach are that the meridional streamsurface does not have to be of a prescribed shape, and by introducing density weighted averages the continuity equation is of an exact form. Included in the equations are the effects of blade blockage, blade forces, blade-to-blade variations and loss. The solution of the equations is developed for the well-known streamline curvature method, and the contributions from these extra effects on the radial equilibrium equation are discussed. Part II of the paper incorporates the analysis into a quasi-three-dimensional computing system and demonstrates its operational feasibility.

The Control of Non-Axisymmetric Flow in Axial Turbomachinery Using Circumferentially Varying Stator Exit Angles

2000 ◽  
Author(s):  
Jonathan Taylor ◽  
Tom Hynes
Keyword(s):  
Design Method ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Design Strategies ◽  
Inlet Distortion ◽  
Alternative Approach ◽  
Blade Row ◽  
Actuator Disc ◽  
Flow Through ◽  
The Impact

Turbomachinery operating in distorted flowfields is often very close to the sources of the distortion, and can influence the flowfield distortions at its inlet and outlet. Several techniques are available to reduce the impact of an upstream-running outlet distortion on the turbomachinery by introducing circumferential variation in the most downstream stator row. However, these techniques assume that the upstream-running distortion is not changed by the modifications to the turbomachinery, and none of them addresses the issue of inlet distortion, either on its own or in combination with outlet distortion. A methodology to design circumferentially varying stator angles has been developed. This is based on a two-dimensional linearisation of the distorted flow through the turbomachinery, combined with information from three-dimensional flowfield calculations. The resulting new design method has been applied to an installed lift fan operating with considerable inlet and outlet distortion. The distorted flow through the lift fan is computed by a three-dimensional numerical method incorporating an actuator disc blade row model. The new design method is then used to produce several redesigned builds with circumferentially varying stator exit angles. The three-dimensional flow through the new builds is computed, and compared with flow through the axisymmetric fan. The calculations show that existing non-axisymmetric design strategies may not be applicable to installations having large flowfield distortions. An alternative approach based on unsteady rotor loading is presented, and relatively small stator exit angle variations are shown to produce significant reductions in this quantity.

A Three-Dimensional Analysis Code of Compressor Performance and Stability for Steady Inlet Distortion

2015 ◽  
Author(s):  
Jin Guo ◽  
Jun Hu ◽  
Chao Yin
Keyword(s):  
Flow Field ◽  
Entropy Production ◽  
Three Dimensional ◽  
Design System ◽  
Force Model ◽  
Source Terms ◽  
Local Flow ◽  
Inlet Distortion ◽  
Velocity Circulation ◽  
Compressor Performance

Inlet distortion has a great impact on the compressor performance and stability. Developing a model which quickly and accurately can assess the performance and stability of a compressor with inlet distortion is one of the key technologies needed to improve the fidelity of a compressor design system. Thus, a new 3-D analysis code called CSAC based on the theory of body force model has been developed and used to predict compressor performance and stability with inlet distortion. The code solves the compressible 3-D Euler equations modified to include source terms which represent the effect of the blade rows. The source terms were calculated by the velocity circulation vectors and entropy production which were extracted from the 3-D Navier-Stokes (N-S) steady-state solutions at the stations between each blade row at many operating points with clean inflow. An analysis was carried out to determine the local flow conditions for parameterizing the magnitude of the velocity circulation vectors and entropy production of individual blade rows. A NASA stage 35 flow field with clean inlet was simulated with the code. The calculation results agreed well with the N-S solutions and experimental data. The stage 35 performance and stability with inlet steady circumferential total pressure distortion was also simulated using the code. The predicted performance maps of the stage 35 with inlet distortion showed a reduced range and pressure rise. In addition, the results reflected the strong three-dimensional characteristics of the flow field with inlet distortion, and the interaction of the blade rows with the upstream flow field. This paper describes the modeling method of CSAC and presents a detailed examination of the computed results.

Assessing Viscous Body Forces for Unsteady Calculations

2003 ◽  
Vol 125 (3) ◽  
pp. 425-432 ◽  
Author(s):  
L. Xu
Keyword(s):  
Drag Coefficient ◽  
Body Force ◽  
Three Dimensional ◽  
Viscous Force ◽  
Local Source ◽  
Source Terms ◽  
Viscous Effects ◽  
Computational Mesh ◽  
Blade Row ◽  
Computational Resources

A strategy has been developed to model the three-dimensional unsteady flows through turbomachines subject to nonaxisymmetric flow/geometrical conditions such as low order distortions with relatively long length-scale unsteadiness, by modeling the viscous effects as local source terms for a coarse computational mesh, but not calculating them directly. In general full annulus multi-row calculations are required for such flows, but currently the computational resources are devoted to resolving detailed viscous flow very close to the walls, which in some cases is not the center of concern. By avoiding resolving detailed viscous effects the model can accelerate the calculation by at least two orders of magnitude. The method has been illustrated to be able to resolve disturbances down to the blade passing frequency and give good estimates of overall unsteady blade forces due to blade row interactions. Obviously, the correct modeling of the viscous body force as source terms in the governing equations is the key for accuracy of such calculations. Different ways of constructing/approximating the viscous body force term are discussed and their adequacy in unsteady flow calculations is assessed. It is found that in general the viscous force is relatively small compared to the total blade force, even smaller the unsteady fluctuation of the viscous force and a simple drag coefficient model is quite adequate to model both time mean and dynamic viscous effects. However, for the cases when separations are present variations in the drag coefficient may become large and more detailed modeling may be required.

The Design and Testing of a Radial Flow Turbine for Aerodynamic Research

1992 ◽  
Vol 114 (2) ◽  
pp. 411-418 ◽  
Author(s):  
I. Huntsman ◽  
H. P. Hodson ◽  
S. H. Hill
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Three Dimensional ◽  
Surface Flow ◽  
Gas Generator ◽  
Low Speed ◽  
Streamline Curvature ◽  
Blade Row ◽  
Scaling Parameters ◽  
Design And Testing

This paper describes the design of a high-speed radial inflow turbine for use as part of a gas generator, and the design of a large-scale (1.2 m tip diameter) low-speed model of the high-speed turbine. Streamline curvature throughflow, two-dimensional blade-to-blade, and fully three-dimensional inviscid and viscous calculation methods have been used extensively in the analysis of the designs. The use of appropriate scaling parameters and their impact on turbine performance is discussed. A simple model shows, for example, how to model the blade lean in the inducer, which serves to balance the effect of meridional curvature at inlet to the rotor and can be used to unload the rotor tip. A brief description of the low-speed experimental facility is followed by a presentation and discussion of experimental results. These include surface flow visualization patterns on both the rotor and stator blades and blade row exit traverses.

Unsteady Three-Dimensional Analysis of Inlet Distortion in a Transonic Fan

2006 ◽  
Author(s):  
Peng Sun ◽  
Guotal Feng
Keyword(s):  
Shock Wave ◽  
Total Pressure ◽  
Large Scale ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Inlet Distortion ◽  
Flow Loss ◽  
Large Scale Vortex ◽  
Total Temperature ◽  
Transonic Fan

A time-accurate three-dimensional Navier-Stokes solver of the unsteady flow field in a transonic fan was carried out using "Fluent-parallel" in a parallel supercomputer. The numerical simulation focused on a transonic fan with inlet square wave total pressure distortion and the analysis of result consisted of three aspects. The first was about inlet parameters redistribution and outlet total temperature distortion induced by inlet total pressure distortion. The pattern and causation of flow loss caused by pressure distortion in rotor were analyzed secondly. It was found that the influence of distortion was different at different radial positions. In hub area, transportation-loss and mixing-loss were the main loss patterns. Distortion not only complicated them but enhanced them. Especially in stator, inlet total pressure distortion induced large-scale vortex, which produced backflow and increased the loss. While in casing area, distortion changed the format of shock wave and increased the shock loss. Finally, the format of shock wave and the hysteresis of rotor to distortion were analyzed in detail.

Effects of Inlet Distortion on the Flow Field in a Transonic Compressor Rotor

1996 ◽  
Author(s):  
Chunill Hah ◽  
Douglas C. Rabe ◽  
Thomas J. Sullivan ◽  
Aspi R. Wadia
Keyword(s):  
Boundary Layer ◽  
Flow Field ◽  
Viscous Flow ◽  
Total Pressure ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Aerodynamic Loss ◽  
Transonic Compressor ◽  
Inlet Distortion ◽  
Compressor Rotor

The effects of circumferential distortions in inlet total pressure on the flow field in a low-aspect-ratio, high-speed, high-pressure-ratio, transonic compressor rotor are investigated in this paper. The flow field was studied experimentally and numerically with and without inlet total pressure distortion. Total pressure distortion was created by screens mounted upstream from the rotor inlet. Circumferential distortions of 8 periods per revolution were investigated at two different rotor speeds. The unsteady blade surface pressures were measured with miniature pressure transducers mounted in the blade. The flow fields with and without inlet total pressure distortion were analyzed numerically by solving steady and unsteady forms of the Reynolds-averaged Navier-Stokes equations. Steady three-dimensional viscous flow calculations were performed for the flow without inlet distortion while unsteady three-dimensional viscous flow calculations were used for the flow with inlet distortion. For the time-accurate calculation, circumferential and radial variations of the inlet total pressure were used as a time-dependent inflow boundary condition. A second-order implicit scheme was used for the time integration. The experimental measurements and the numerical analysis are highly complementary for this study because of the extreme complexity of the flow field. The current investigation shows that inlet flow distortions travel through the rotor blade passage and are convected into the following stator. At a high rotor speed where the flow is transonic, the passage shock was found to oscillate by as much as 20% of the blade chord, and very strong interactions between the unsteady passage shock and the blade boundary layer were observed. This interaction increases the effective blockage of the passage, resulting in an increased aerodynamic loss and a reduced stall margin. The strong interaction between the passage shock and the blade boundary layer increases the peak aerodynamic loss by about one percent.

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