scholarly journals A Study of the Flow through the Rotor of an Axial-Compressor : A Proposition of Formulas of Drag Coefficients

1962 ◽  
Vol 5 (18) ◽  
pp. 292-301 ◽  
Author(s):  
Kunio FUJIE
Keyword(s):  
Axial Compressor ◽  
Drag Coefficients ◽  
Flow Through

scholarly journals Simplified Method for Flow Analysis and Performance Calculation Through an Axial Compressor

1984 ◽  
Author(s):  
Hubert Miton ◽  
Youssef Doumandji ◽  
Jacques Chauvin
Keyword(s):  
Equations Of Motion ◽  
Computing Time ◽  
Flow Analysis ◽  
Axial Compressor ◽  
Computation Method ◽  
Duct Flow ◽  
Axial Compressors ◽  
Flow Through ◽  
And Performance ◽  
Performance Calculation

This paper describes a fast computation method of the flow through multistage axial compressors of the industrial type. The flow is assumed to be axisymmetric between the blade rows which are represented by actuator disks. Blade row losses and turning are calculated by means of correlations. The equations of motion are linearized with respect to the log of static pressure, whose variation along the radius is usually of limited extent for the type of machines for which the method has been developed. In each computing plane (i.e. between the blade rows) two flows are combined: a basic flow with constant pressure satisfying the mass flow requirements and a perturbation flow fulfilling the radial equilibrium condition. The results of a few sample calculations are given. They show a satisfactory agreement with a classical duct flow method although the computing time is reduced by a factor five. The method has also been coupled with a surge line prediction calculation.

Drag coefficients for modeling flow through emergent vegetation in the Florida Everglades

2004 ◽  
Vol 22 (4-5) ◽  
pp. 237-248 ◽  
Author(s):  
Jonathan K. Lee ◽  
Lisa C. Roig ◽  
Harry L. Jenter ◽  
Hannah M. Visser
Keyword(s):  
Emergent Vegetation ◽  
Florida Everglades ◽  
Drag Coefficients ◽  
Flow Through ◽  
Modeling Flow

193 A Study of Leakage Flow through Linear Cascade in an Axial Compressor : Effect of Shroud Size

2013 ◽  
Vol 2013.48 (0) ◽  
pp. 188-189
Author(s):  
Masafumi KUMAGAI ◽  
Ken-ichi FUNAZAKI ◽  
Hideo TANIGUCHI ◽  
Hiromasa KATO ◽  
Ryutaro ISHIMURA ◽  
...  
Keyword(s):  
Axial Compressor ◽  
Leakage Flow ◽  
Linear Cascade ◽  
Flow Through

Numerical Investigation on Tandem Compressor Cascades

2015 ◽  
Author(s):  
Manas Madasseri Payyappalli ◽  
S. R. Shine
Keyword(s):  
Model Comparison ◽  
Numerical Study ◽  
Incidence Angle ◽  
Axial Compressor ◽  
Flow Structures ◽  
Finite Volume Scheme ◽  
Axial Compressors ◽  
Flow Mechanisms ◽  
Flow Through ◽  
Tandem Cascades

Tandem blade arrangement of axial compressors has been proposed to obtain high loading and turning compared to a single blade. The objectives of the current study is to investigate the effect of percent pitch, axial overlap and incidence angle for a low speed axial compressor stator cascade and to supplement the results with the flow structures observed. 2-D numerical study was conducted using a finite volume scheme which solves the RANS equations along with the Spalart-Allmaras turbulence model. Comparison offlow structures corresponding to different percent pitch, axial overlap and incidence angle has been made to highlight all prominent flow mechanisms. It is observed that the flow through the gap nozzle between the two blades has significant effects on losses. The incidence range of the tandem cascades is found to be superior to the corresponding single blade cases.

Investigation Into Core Compressor Tip Leakage Modelling Techniques Using a 3D Viscous Solver

2001 ◽  
Author(s):  
Jonathan P. Glanville
Keyword(s):  
Transport Model ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Leakage Flow ◽  
Tip Leakage ◽  
Leakage Flows ◽  
Modelling Techniques ◽  
Flow Through ◽  
Tip Leakage Flows

The leakage flow through the tip clearance gap of an axial compressor has a significant effect on loss production and stall behaviour. Accurate modelling is essential if improved designs are to be developed which control such flows. Studies have been carried out using the DERA TRANSCode 3D Reynolds-Averaged Navier-Stokes code to predict the tip leakage flows in a low speed research compressor. Calculations were carried out using both a simple pinched-tip model and an improved mesh which allowed the true square-tip geometry to be represented. Comparisons between the Baldwin-Lomax algebraic turbulence model and the Spalart-Allmaras one-equation transport model were also made. The results showed that the predictions of both the detailed flows and the loss levels were sensitive to the modelling and that substantial improvements in accuracy were possible.

scholarly journals Numerical Simulation of Rotating Stall in Axial Compressor Blade Rows and Stages

1986 ◽  
Author(s):  
H. G. Neuhoff ◽  
K. G. Grahl
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Compressor Blade ◽  
Time Step ◽  
Time Constants ◽  
Compressor Rotor ◽  
Cascade Flow ◽  
Flow Through ◽  
Transonic Fan ◽  
Highly Loaded

Rotating stall is simulated by a time step integration procedure of the Euler equations. The prescribed compressors consist of finite inlet and outlet ducts, blade rows of finite chord lengths and a throttle without impedance. Due to this compressor model the net mass flow through the compressor remains constant during the transient to fully developed rotating stall. Results are presented for a highly loaded rotor and a transonic fan stage. Contrary to former nonlinear approaches, the presented theory indicates that the fully developed rotating stall in a single compressor rotor is not affected by the number of lobes of an initial circumferential disturbance. For a highly loaded stage the dependence of the stall parameters on the time constants of the cascade flow is demonstrated.

Nonaxisymmetric Flow through Annular Actuator Disks: Inlet Distortion Problem

1978 ◽  
Vol 100 (4) ◽  
pp. 604-617 ◽  
Author(s):  
W. R. Hawthorne ◽  
N. A. Mitchell ◽  
J. E. McCune ◽  
C. S. Tan
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Recent Experimental Data ◽  
Recent Theory ◽  
Inlet Distortion ◽  
Actuator Disk ◽  
Beltrami Flow ◽  
Compressor Rotor ◽  
Flow Through ◽  
Absolute Coordinates

The passage of distorted flow through an annular axial compressor rotor or stator is analyzed in the actuator disk limit. In such a description the flow is steady in absolute coordinates. The resulting analysis yields an overall description of the blade row performance in the presence of inlet flow defects. The present (actuator-disk) analysis is compared successfully with Dunham’s earlier three-dimensional analysis as well as with recent experimental data. In addition, comparison with a recent theory by Greitzer, employing an alternative approach, is made. The analysis shows that at least two important distinct types of vorticity arise, the one being directly analogous to the trailing vorticity (shed circulation) of classical wing theory, and the second being analogous to the vorticity occurring in “secondary flow” theory. The latter arises directly as a result of inlet distortion. The resulting varying flow angles produce spanwise variation in blade loading, and consequent trailing vorticity (Beltrami Flow). The two types of vorticity are therefore interrelated. The static pressure field is also affected by this coupling in agreement with experiment. This problem provided a striking example for which three-dimensional and two-dimensional analyses disagree qualitatively. The vorticity as viewed in coordinates fixed in the rotor is discussed in the Addendum.

Numerical Study on the Effects of Casing Treatment on Unsteadiness of Tip Leakage Flow in an Axial Compressor

2012 ◽  
Author(s):  
Yoojun Hwang ◽  
Shin-Hyoung Kang
Keyword(s):  
Numerical Study ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Casing Treatment ◽  
Tip Leakage ◽  
Operating Range ◽  
Compressor Rotor ◽  
Flow Through

A low speed axial compressor with casing treatment of axial slots was numerically investigated. Time-accurate numerical calculations were performed to simulate unsteady flow in the rotor tip region and the effects of casing treatment on the flow. Since the compressor rotor had a large tip clearance, it was found that the tip leakage flow had an inherent unsteady feature that was not associated with rotor rotation. The unsteadiness of the tip leakage flow was induced by changes in the blade loading due to the pressure distribution formed by the tip leakage flow. This characteristic is called rotating instability or self-induced unsteadiness. The frequency of the flow oscillation was found to decrease as the flow rate was reduced. On the other hand, as expected, the operating range was improved by casing treatment, as shown by calculations in good agreement with the experimentally measured data. The unsteadiness of the tip leakage flow was alleviated by the casing treatment. The interaction between the flow in the tip region and the re-circulated flow through the axial slots was observed in detail. The removal and injection of flow through the axial slots were responsible not only for the extension of the operating range but also for the alleviation of the unsteadiness. Analyses of instantaneous flow fields explained the mechanism of the interaction between the casing treatment and the unsteady oscillation of the tip leakage flow. Furthermore, the effects of changes in the amount of re-circulation and the location of the removal and injection flow on the unsteadiness of the tip leakage flow were examined.

Evaluation of Flow Field Approximations for Transonic Compressor Stages

1996 ◽  
Author(s):  
Daniel J. Dorney ◽  
Om P. Sharma
Keyword(s):  
Flow Field ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Loosely Coupled ◽  
Transonic Compressor ◽  
Blade Row ◽  
Flow Through ◽  
And Performance ◽  
Computer Resources ◽  
Fully Coupled

The flow through gas-turbine compressors is often characterized by unsteady, transonic and viscous phenomena. Accurately predicting the behavior of these complex multi-blade-row flows with unsteady rotor-stator interacting Navier-Stokes analyses can require enormous computer resources. In this investigation, several methods for predicting the flow field, losses and performance quantities associated with axial compressor stages are presented. The methods studied include, 1) the unsteady fully-coupled blade row technique, 2) the steady coupled blade row method, 3) the steady single blade row technique, and 4) the loosely-coupled blade row method. The analyses have been evaluated in terms of accuracy and efficiency.

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