Turbulent Boundary Layers on Centrifugal Compressor Blades: Prediction of the Effects of Surface Curvature and Rotation

1976 ◽  
Vol 98 (3) ◽  
pp. 374-381 ◽  
Author(s):  
J. P. Johnston ◽  
S. A. Eide
Keyword(s):  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Factor H ◽  
Rotor Blades ◽  
Data Sets ◽  
Compressor Blades ◽  
Simple Method ◽  
Compressor Rotor ◽  
Attached Flow ◽  
Effects Of Rotation

A method for calculation of turbulent boundary layers on curved, rotating surfaces is presented, and the applicability of the method to the prediction of attached flow over compressor rotor blades is indicated. Calculated results are compared to existing data sets. Additional sample calculations to study the effects of rotation are also presented. Correlations of these calculated results provide a simple method for estimation of the effects of rotation on skin friction, cf, and boundary-layer shape factor, H.

An Approach to Three-Dimensional Turbulent Boundary Layers

1966 ◽  
Author(s):  
A. D. Carmichael
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Shape Factor ◽  
Basic Assumption ◽  
Three Dimensional ◽  
Cross Flow ◽  
Turbulent Boundary Layers ◽  
Factor H ◽  
Simple Method ◽  
The Cross

A relatively simple method for predicting some of the characteristics of three-dimensional turbulent boundary layers is presented. The basic assumption of the method is that the cross-flow is small. An empirical correlation of a basic shape factor of the cross-flow boundary layer against the streamwise shape factor H is provided. This correlation, together with data for the streamwise boundary layer, is used to predict the cross flow. The solution is very sensitive to the accuracy of the streamwise boundary-layer data which is predicted by conventional two-dimensional methods.

A Mixing-Length Model for the Prediction of Convex Curvature Effects on Turbulent Boundary Layers

1984 ◽  
Vol 106 (1) ◽  
pp. 142-148 ◽  
Author(s):  
E. W. Adams ◽  
J. P. Johnston
Keyword(s):  
Heat Transfer ◽  
Layer Thickness ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Radius Of Curvature ◽  
Data Sets ◽  
Mixing Length ◽  
Flat Wall ◽  
Curvature Effects ◽  
Layer Thickness Ratio

A mixing-length model is developed for the prediction of turbulent boundary layers with convex streamwise curvature. For large layer thickness ratio, δ/R > 0.05, the model scales mixing length on the wall radius of curvature, R. For small δ/R, ordinary flat wall modeling is used for the mixing-length profile with curvature corrections, following the recommendations of Eide and Johnston [7]. Effects of streamwise change of curvature are considered; a strong lag from equilibrium is required when R increases downstream. Fifteen separate data sets were compared, including both hydrodynamic and heat transfer results. In this paper, six of these computations are presented and compared to experiment.

Stator Blades Manufacturing Geometrical Variability in Axial Compressors and Impact on the Aeroelastic Excitation Forces

2021 ◽  
pp. 1-16
Author(s):  
Marco Gambitta ◽  
Arnold Kühhorn ◽  
Bernd Beirow ◽  
Sven Schrape
Keyword(s):  
Manufacturing Process ◽  
Axial Compressor ◽  
Reconstruction Algorithm ◽  
Forced Response ◽  
Rotor Blades ◽  
Compressor Blades ◽  
Input Uncertainty ◽  
Axial Compressors ◽  
Compressor Rotor ◽  
The Impact

Abstract The manufacturing geometrical variability is an unavoidable source of uncertainty in the realization of machinery components. Deviations of a part geometry from its nominal design are inevitably present due to the manufacturing process. In the aeroelastic forced response problem within axial compressors, these uncertainties may affect the vibration characteristics. Therefore, the impact of geometrical uncertainties due to the manufacturing process onto the modal forcing of axial compressor blades is investigated. The research focuses on the vibrational behavior of an axial compressor rotor blisk. In particular, the amplitude of the forces acting as source of excitation on the vibrating blades is studied. The geometrical variability of the upstream stator is investigated as input uncertainty. The variability is modeled starting from a series of optical surface scans. A stochastic model is created to represent the measured manufacturing geometrical deviations from the nominal model. A data reduction methodology is proposed to represent the uncertainty with a minimal set of variables. The manufacturing geometrical variability model allows to represent the input uncertainty and probabilistically evaluate its impact on the aeroelastic problem. An uncertainty quantification is performed in order to evaluate the resulting variability on the modal forcing acting on the vibrating rotor blades. Of particular interest is the possible rise of low engine orders due to the mistuned flow field along the annulus. A reconstruction algorithm allows the representation of the variability during one rotor revolution. The uncertainty on low harmonics of the modal rotor forcing can be therefore identified and quantified.

Stator Blades Manufacturing Geometrical Variability in Axial Compressors and Impact on the Aeroelastic Excitation Forces

2021 ◽  
Author(s):  
Marco Gambitta ◽  
Arnold Kühhorn ◽  
Bernd Beirow ◽  
Sven Schrape
Keyword(s):  
Manufacturing Process ◽  
Axial Compressor ◽  
Reconstruction Algorithm ◽  
Forced Response ◽  
Rotor Blades ◽  
Compressor Blades ◽  
Input Uncertainty ◽  
Axial Compressors ◽  
Compressor Rotor ◽  
The Impact

Abstract The manufacturing geometrical variability is a source of uncertainty, which cannot be avoided in the realization of machinery components. Deviations of a part geometry from its nominal design are inevitably present due to the manufacturing process. In the case of the aeroelastic forced response problem within axial compressors, these uncertainties may affect the vibration characteristics. For this reason, the impact of geometrical uncertainties due to the manufacturing process onto the modal forcing of axial compressor blades is investigated in this study. The research focuses on the vibrational behavior of an axial compressor rotor blisk. In particular the amplitude of the forces acting as source of excitation on the vibrating blades is studied. The geometrical variability of the upstream stator is investigated as input uncertainty. The variability is modeled starting from a series of optical surface scans. A stochastic model is created to represent the measured manufacturing geometrical deviations from the nominal model. A data reduction methodology is proposed in order to represent the uncertainty with a minimal set of variables. The manufacturing geometrical variability model allows to represent the input uncertainty and probabilistically evaluate its impact on the aeroelastic problem. An uncertainty quantification is performed in order to evaluate the resulting variability on the modal forcing acting on the vibrating rotor blades. Of particular interest is the possible rise of low engine orders due to the mistuned flow field along the annulus. A reconstruction algorithm allows the representation of the variability during one rotor revolution. The uncertainty on low harmonics of the modal rotor forcing can be therefore identified and quantified.

Effects of Blade Damage on the Performance of a Transonic Axial Compressor Rotor

2012 ◽  
Author(s):  
Yanling Li ◽  
Abdulnaser Sayma
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Rotor Blades ◽  
Design Stage ◽  
Compressor Blades ◽  
Stall Margin ◽  
Compressor Rotor ◽  
Surge Margin ◽  
Compressor Performance ◽  
Transonic Axial Compressor

Gas turbine axial compressor blades may encounter damage during service for various reasons. Debris from casing or foreign objects may impact blades causing damage near the rotor’s tip. This may result in deterioration of performance and reduction in the surge margin. Ability to assess the effect of damaged blades on the compressor performance and stability is important at both the design stage and in service. The damage to compressor blades breaks the cyclic symmetry of the compressor assembly. Thus computations have to be performed using the whole annulus. Moreover, if rotating stall or surge occurs, the downstream boundary conditions are not known and simulations become difficult. This paper presents an unsteady CFD analysis of compressor performance with tip curl damage. Tip curl damage typically occurs when rotor blades hit a loose casing liner. The computations were performed up to the stall boundary, predicting rotating stall patterns. The aim is to assess the effect of blade damage on stall margin and provide better understanding of the flow behaviour during rotating stall. Computations for the undamaged rotor are also performed for comparison. A transonic axial compressor rotor is used for the time-accurate numerical unsteady flow simulations, with a variable choked nozzle downstream simulating an experimental throttle. One damaged blade was introduced in the rotor assembly and computations were performed at 60% of the design rotational speed. It was found that there is no significant effect on the compressor stall margin due to one damaged blade despite the differences in rotating stall patterns between the undamaged and damaged assemblies.

scholarly journals The Prediction of Boundary Layers With Rotation and Variation of Stream Filament Thickness

1989 ◽  
Author(s):  
Hua Yaonan ◽  
Wang Baoguo
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Present Method ◽  
Axial Compressor ◽  
Momentum Equation ◽  
Stream Surface ◽  
Boundary Layer Equations ◽  
Compressor Rotor ◽  
Transonic Axial Compressor ◽  
Effects Of Rotation

The boundary layer equations with accounting for rotation and variation of stream filament thickness on the Sl stream surface of revolution in turbomachinery are derived in this paper. A method is presented for calculating laminar, turbulent and wake boundary layers by means of solving the integral momentum equation. The turbulent boundary layer with separation also can be calculated by use of present method. The prediction of the boundary layer on the cascade blade of the DFVLR transonic axial compressor rotor was carried out in this paper. The effects of rotation and variation of stream filament thickness on the predicted behavior of the boundary layer are carefully investigated. It is shown that in certain cases their effects on the predicted results are significant.

Fractal characteristics of turbulent–non-turbulent interface in supersonic turbulent boundary layers

2018 ◽  
Vol 843 ◽  
Author(s):  
Yi Zhuang ◽  
Huijun Tan ◽  
Hexia Huang ◽  
Yazhou Liu ◽  
Yue Zhang
Keyword(s):  
Boundary Layers ◽  
Large Scale ◽  
Turbulent Boundary Layers ◽  
Data Sets ◽  
Scaling Exponent ◽  
Supersonic Wind Tunnel ◽  
Laser Scattering ◽  
Box Counting ◽  
Planar Laser ◽  
Scale Range

The turbulent–non-turbulent interface (TNTI) of supersonic turbulent boundary layers is a fundamental but relatively unexplored physics problem. In this study, we present experimental results from fractal analysis on the TNTI of supersonic turbulent boundary layers, and test the applicability of the additive law for these flows. By applying the nanoparticle-tracer planar laser scattering (NPLS) technique in a supersonic wind tunnel, we obtain data covering nearly three decades in scale. The box-counting results indicate that the TNTI of supersonic turbulent boundary layers is a self-similar fractal with a fractal dimension of 2.31. By comparing data sets acquired from two orthogonal planes, we find that the scaling exponent does not depend on direction, consistent with the validity of the additive law for the TNTI of turbulent boundary layers in a scale range with the large-scale limit not exceeding approximately $0.05\unicode[STIX]{x1D6FF}$.

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.

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