The Calculation of Deviation Angle in Axial-Flow Compressor Cascades

1983 ◽  
Vol 105 (3) ◽  
pp. 474-479 ◽  
Author(s):  
L. C. Wang ◽  
R. Hetherington ◽  
A. Goulas
Keyword(s):  
Stokes Equations ◽  
Pressure Coefficient ◽  
Axial Flow ◽  
Navier Stokes ◽  
Angle Of Incidence ◽  
Deviation Angle ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Vorticity Transport ◽  
Good Agreement

The deviation angles of axial flow compressor cascades have been predicted by solving the Reynolds averaged fully turbulent Navier-Stokes equations. A finite element method has been used. To close the problem an algebraic eddy viscosity turbulent model has been chosen. The introduction of the idea of vorticity to the governing equation enables the establishment of a relation between the entropy and the vorticity fields, and the vorticity transport differential equation in the stream function-vorticity method is replaced by a differential operation. A series of calculations have been carried out to examine the influence of cascade geometry on the devotion angle. Very good agreement has been obtained for small angles of incidence with the correlations produced by NASA and using Carter’s rule. Good agreement has also been shown for the variation of deviation angle with the angle of incidence with the experimental data of Felix and Emery, as well as for the distribution of the pressure coefficient along the blade axial chord.

An Implicit Off-Design Deviation Angle Correlation of Axial Flow Compressor Blade Elements

2017 ◽  
Author(s):  
Wu Dong-run ◽  
Teng Jin-fang ◽  
Qiang Xiao-qing ◽  
Feng Jin-zhang
Keyword(s):  
Experimental Data ◽  
Incidence Angle ◽  
High Reliability ◽  
Axial Flow ◽  
Compressor Blade ◽  
Deviation Angle ◽  
Axial Flow Compressor ◽  
New Correlation ◽  
Classical Correlations ◽  
Flow Compressor

This paper applies a new analytical/empirical method to formulate the off-design deviation angle correlation of axial flow compressor blade elements. An implicit function of deviation angle is used to map off-design deviation curves into linear correlations (minimum linear correlation coefficient R = 0.959 in this paper). Solution of the coefficients in the correlation is given through the study of classical theories and statistical analysis of the experimental data. The off-design deviation angle can be calculated numerically. The approach requires only knowledge of the blade element geometry. The comparison among 2 classical correlations and the new correlation proposed in this paper shows the new correlation has minimum error over the entire range of incidence angle while classical correlations show high reliability only in a limited range. Experimental data in this paper is collected from NASA’s open technical reports. Rotors and stators are studied together. Considering there is significant deviation angle variation along spanwise direction, only data at 50% span is studied, if possible. The error among experimental data, statistical regressions of the experimental data, and numerical results based on the new correlation is discussed. It has to be noted that the influence of the flow condition other than incidence angle is only being discussed but with less break through.

The Development of an Aerodynamic Performance Prediction Tool for Modern Axial Flow Compressor Profiles

2006 ◽  
Author(s):  
Dario Bruna ◽  
Carlo Cravero ◽  
Mark G. Turner
Keyword(s):  
Performance Prediction ◽  
Parametric Design ◽  
Flow Analysis ◽  
Axial Flow ◽  
Navier Stokes ◽  
Flow Angle ◽  
Flow Solver ◽  
Aerodynamic Loss ◽  
Axial Flow Compressor ◽  
Flow Compressor

The development of a computational tool (MP-LOS) for the aerodynamic loss modeling and prediction for axial-flow compressor blade sections is presented in this paper. A state-of-the-art quasi 3-D flow solver, MISES, has been used for the flow analysis on existing airfoil geometries in many working conditions. Different values of inlet flow angle, inlet Mach number, AVDR, Reynolds number and solidity have been chosen to investigate a possible working range. The target is a loss prediction formulation that will be introduced into throughflow or axisymmetric Navier-Stokes codes for the performance prediction of multistage axial flow compressors. The loss coefficient has been correlated to the flow parameters that have shown an influence on the profile loss for the blades under study. The proposed correlation, using the described computational approach, can be extended to any profile family with the aid of any code for the parametric design of blade profiles.

Analysis of Three-Dimensional Viscous Flow in a Supersonic Axial Flow Compressor Rotor With Emphasis on Tip Leakage Flow

1992 ◽  
Author(s):  
G. Perrin ◽  
F. Leboeuf ◽  
W. N. Dawes
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Axial Flow ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Axial Velocity Component ◽  
Tip Leakage ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor

A three-dimensional computation has been performed for a supersonic axial flow compressor rotor by solving the Navier-Stokes equations. The results of the computation are used to analyse the tip leakage flow in more detail. As well as the global behaviour of the tip leakage vortex, the analysis focuses on the origins of this vortex. It is shown that the main source of its vorticity is the shear layer at the tip of the blade associated with the shedding of the blade loading. A separation occurs, with respect to the axial velocity component, as the jet leakage flow, crossing the clearance gap, encounters the upstream incoming flow. Although the entropy increase of this separation is low, it has a strong effect on the mixing around the leakage vortex. Overall, for this compressor and the choosen operating point, the tip leakage effects are localised near the tip wall and suction side of the blade.

Numerical Flow Prediction in Inlet Pipe of Vertical Inline Pump

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Christopher Stephen ◽  
Shouqi Yuan ◽  
Ji Pei ◽  
Xing Cheng G
Keyword(s):  
Stokes Equations ◽  
Reverse Flow ◽  
Pressure Coefficient ◽  
Navier Stokes ◽  
Mean Flow ◽  
Inlet Pipe ◽  
Navier Stokes Equations ◽  
Computational Fluid Dynamics Cfd ◽  
The Mean ◽  
Good Agreement

For a pump, the inlet condition of flow determines the outlet conditions of fluid (i.e., energy). As a rule to minimize the losses at the entry of pump, the bends should be avoided as one of the methods. But for the case of vertical inline pump, it is unavoidable in order to save the space for installation. For the purpose of investigation in inlet pipe of vertical inline pump, the unsteady Reynolds-averaged Navier–Stokes equations are solved using the computational fluid dynamics (CFD) code. The results have been shown that there is a good agreement between the performance characteristics obtained from the simulation and experiments. The velocity coefficient from the simulation along the inlet pipe sections is well matched with the theoretical values and found to have variation near the exit of inlet pipe. The pressure and velocity coefficients studies depict the flow physics at each section along with the study of helicity at the exit of inlet pipe to determine the recirculation effects. It is observed that the vortices associated with the motion of the particles are moved toward the surfaces and are more intense than the mean flow. The trends of pressure coefficient at the exit of inlet pipe were addressed with reference to the various flow rates for eight set of radial lines. Hence, this work concludes that for inlet pipe, the generation of circulation was due to the stream path and the reverse flow from the impeller and was reconfirmed with the literature.

The Influence of Shrouded Stator Cavity Flows on the Aerodynamic Performance of a High-Speed Multistage Axial-Flow Compressor

2011 ◽  
Author(s):  
Dai Kato ◽  
Mai Yamagami ◽  
Naoki Tsuchiya ◽  
Hidekazu Kodama
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Axial Flow ◽  
Main Flow ◽  
Navier Stokes ◽  
Cavity Flows ◽  
Axial Flow Compressor ◽  
First Case ◽  
Flow Compressor ◽  
Unsteady Effects

This paper investigates numerically the effects of shrouded stator seal cavity flows on a high-speed, six-stage, advanced axial-flow compressor performance. Two cases of fully three-dimensional unsteady Reynolds-averaged Navier-Stokes simulations are performed. The first case includes only the main flow path without cavities, while the second case takes into account the effect of cavities by fully meshing and solving the seal cavity flows under each of the stator vanes. Both simulations included rotor blade tip clearances. The latter case showed 1.7 point degradation in efficiency from the first case. Contributors to the overall performance degradation, such as windage heating, mixing loss due to seal leakage flow with the main flow, and additional loss of the rotors and stators due to alteration in velocity triangles, are identified by comparing the two simulation results. Compared to theoretical or semi-empirical leakage and windage models, higher loss production and temperature rise are found especially in mid to rear stages. Unsteady effects for such differences are discussed.

Reverse Flow Turbine-Like Operation of an Axial Flow Compressor

2012 ◽  
Author(s):  
A. Gill ◽  
T. W. von Backström ◽  
T. M. Harms
Keyword(s):  
Reverse Flow ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Harmonic Approximation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Time Dependent ◽  
Navier Stokes ◽  
Axial Flow Compressor ◽  
Flow Compressor

This article describes an experimental investigation of the flow structures occurring in an axial flow compressor during second quadrant operation for reversed rotor rotation in the incompressible flow regime. In second quadrant operation, the flow direction is reversed, but the pressure is lower at the compressor inlet than at the outlet. The compressor thus acts as an axial flow turbine. A three stage axial flow compressor, with a mass flow rate of 2.7 kg/s and a pressure ratio of 1.022 was investigated. The design rotor tip Mach number is 0.2. Three operational points within the second quadrant were investigated, at flow coefficients of −0.482, −0.553 and −0.843. A five hole conical probe and a 50 micron diameter inclined hot film anemometer were used in this investigation. Radial traverses downstream of rotor rows and a time-dependent area traverse downstream of the first stage stator were performed. Three-dimensional time-dependent numerical Navier-Stokes solutions using the non-linear harmonic approximation for single blade passages in each blade row for each of the cases are compared with experimental work. The compressor has already been show to be capable of attaining relatively high turbine efficiency (76%) when operating in this mode. Examination of the flow field shows that little to no flow separation occurs on the rotor or stator blades. The wakes of all blades are found to be thin and sharp, and the area between wakes is large and approximately uniform. Numerical results agree relatively well with experimental results.

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