3D Transonic Potential Flow Computation in an Axial-Flow Compressor Rotor by an Approximate Factorization Scheme

1986 ◽  
Vol 108 (1) ◽  
pp. 112-117
Author(s):  
Jialin Zhang
Keyword(s):  
Flow Field ◽  
Transonic Flow ◽  
Axial Flow ◽  
Curvilinear Coordinates ◽  
Full Potential ◽  
Approximate Factorization ◽  
Factorization Scheme ◽  
Compressor Rotor ◽  
Fully Implicit ◽  
Flow Compressor

A conservative full-potential equation of 3D transonic flow in a turbomachine has been derived with the tensor method and expressed with respect to nonorthogonal curvilinear coordinates, and a fully implicit approximate factorization scheme to calculate the flow field has been developed in this paper. The new algorithm has been used to compute the 3D transonic flow field within an axial-flow single-stage compressor rotor tested by DFVLR. Comparisons between the computed flow field and the DFVLR data have been made. Results demonstrate that fast convergence can be achieved by the presented algorithm and that the agreement with the measurements obtained with an advanced laser velocimeter is quite good.

scholarly journals 3D Flow Field Measurement Around a Rotating Stall Cell

1998 ◽  
Author(s):  
C. Palomba ◽  
P. Puddu ◽  
F. Nurzia
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Field Pattern ◽  
Mean Flow ◽  
Axial Section ◽  
Average Technique ◽  
Compressor Rotor ◽  
Flow Compressor

Rotating stall is an unsteady phenomenon that arises in axial and radial flow compressors. Under certain operating conditions a more or less regular cell of turbulent flow develops and propagates around the annulus at a speed lower than rotor speed. Recently little work has been devoted to the understanding of the flow field pattern inside a rotating cell. However, this knowledge could be of help in the understanding of the interaction between the cell and the surrounding flow. Such information could be extremely important during the modelling process when some hypothesis have to be made about the cell behaviour. A detailed experimental investigation has been conducted during one cell operation of an isolated low-speed axial flow compressor rotor using a slanted hot wire and an ensemble average technique based on the cell revolution time. The three flow field components have been measured on 9 axial section for 800 circumferential points and on 21 radial stations to give a complete description of the flow field upstream and downstream of the rotor. Interpretation of data can give a description of the mean flow field patterns inside and around the rotating cell.

A New Approach to the Experimental Study of Turbomachinery Flow Phenomena

1977 ◽  
Vol 99 (1) ◽  
pp. 97-105 ◽  
Author(s):  
J. P. Gostelow
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Axial Flow ◽  
Centrifugal Pumps ◽  
New Approach ◽  
Static Pressure Distribution ◽  
Compressor Rotor ◽  
Flow Phenomena ◽  
On Line ◽  
Flow Compressor

Measurements of the unsteady flow field over a rotor and within its wake are needed in the development of most turbomachines. The technique advocated is that of data acquisition by on-line computer, using the periodic passing of a blade as a phase reference. The phase-lock averaging process is described as is its use in reducing the noise of raw data traces. Measurements of the unsteady flow over a cascade and of the resulting boundary layer behavior are presented. The approach was used in interpreting the unsteady flow field of an axial-flow compressor rotor and the static pressure distribution over the rotor tip. Finally the application to centrifugal pumps is discussed, enabling the designer to obtain information on the suction pressures and the extent of any separated region.

Computation of Potential Flow on S2 Stream Surface for a Transonic Axial-Flow Compressor Rotor

1985 ◽  
Vol 107 (2) ◽  
pp. 323-328 ◽  
Author(s):  
Pan-Ming Lu¨ ◽  
Chung-Hua Wu
Keyword(s):  
Potential Function ◽  
Axial Compressor ◽  
Axial Flow ◽  
Full Potential ◽  
Stream Surface ◽  
Compressor Rotor ◽  
Transonic Axial Compressor ◽  
Design Speed ◽  
Flow Compressor ◽  
Good Agreement

A set of conservative full potential function equations governing the fluid flow along a given S2 streamsurface in a transonic axial compressor rotor was obtained. By the use of artificial density and a potential function/density iteration, this set of equations can be solved, and the passage shock on the S2 streamsurface can be captured. A computer program for this analysis problem has been developed and used to compute the flow field along a mean S2 streamsurface in the DFVLR transonic axial compressor rotor. A comparison of computed results with DFVLR L2F measurement at 100 percent design speed shows fairly good agreement.

scholarly journals Transonic Flow Along Arbitrary Stream Filament of Revolution Solved by Separate Computations With Shock Fitting

1986 ◽  
Author(s):  
Wang Baoguo ◽  
Hua Yaonan ◽  
Huang Xiaoyan ◽  
Wu Chung-Hua
Keyword(s):  
Flow Field ◽  
Stream Function ◽  
Transonic Flow ◽  
Matrix Method ◽  
Axial Compressor ◽  
Iteration Scheme ◽  
Curvilinear Coordinates ◽  
Algebraic Equations ◽  
Compressor Rotor ◽  
Orthogonal Curvilinear Coordinates

The transonic flow field in a cascade of blades lying on an S1 stream surface of revolution is solved by separate computations in the supersonic and the transonic region. The characteristics method is used to solve the supersonic flow upstream of the passage shock and the direct matrix method is used to solve the transonic flow downstream of the passage shock. The transonic stream-function equation in weak conservative form was discretized with respect to general non-orthogonal curvilinear coordinates. Using the artificial density technique and a new iteration scheme between the stream function and the density, the set of algebraic equations was solved by the direct matrix method. A computer program has been developed and is applied to compute the flow field on several S1 stream surfaces of revolution for the DFVLR transonic axial compressor rotor. It is found that the thickness of the S1 stream filament and the variation of entropy along the streamlines have strong influence on calculation. The calculated result agrees with the experimental data fairly well.

scholarly journals Numerical Prediction of Wakes in Cascades and Compressor Rotors Including the Effects of Mixing: Part II — Rotor Passage Flow and Wakes Including the Effects of Spanwise Mixing

1991 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Radial Component ◽  
Navier Stokes ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Entire Flow ◽  
High Reynolds ◽  
Flow Compressor

The results of a numerical investigation to predict the flow field including wakes and mixing in axial flow compressor rotors has been presented in this paper. The wake behaviour in a moderately loaded compressor rotor has been studied numerically using a three-dimensional incompressible Navier-Stokes solver with a high Reynolds number form of the k–ε turbulence model. The equations are solved using a time dependent implicit technique. The agreement between the measured data and the predictions are good; including the blade boundary layer profiles, wake mean velocity profiles and decay. The ability of the pseudo-compressibility scheme to predict the entire flow field including the near and far wake profiles and its decay characteristics, effect of loading and the viscous losses of a three-dimensional rotor flow field has been demonstrated. An analysis of the passage averaged velocities and the pressure coefficients shows that the mixing in the downstream regions away from the hub and annulus walls is dominated by wake diffusion. In regions away from the walls, the radial mixing is predominantly caused by the transport of mass, momentum and energy by the radial component of velocity in the wake.

Numerical Prediction of Wakes in Cascades and Compressor Rotors Including the Effects of Mixing: Part II—Rotor Passage Flow and Wakes Including the Effects of Spanwise Mixing

1992 ◽  
Vol 114 (3) ◽  
pp. 617-626 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Radial Component ◽  
Navier Stokes ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Entire Flow ◽  
High Reynolds ◽  
Flow Compressor

The results of a numerical investigation to predict the flow field including wakes and mixing in axial flow compressor rotors has been presented in this paper. The wake behavior in a moderately loaded compressor rotor has been studied numerically using a three-dimensional incompressible Navier–Stokes solver with a high Reynolds number form of the k–ε turbulence model. The equations are solved using a time-dependent implicit technique. The agreement between the measured data and the predictions is good, including the blade boundary layer profiles, wake mean velocity profiles, and decay. The ability of the pseudocompressibility scheme to predict the entire flow field including the near and far wake profiles and its decay characteristics, effect of loading, and the viscous losses of a three-dimensional rotor flow field has been demonstrated. An analysis of the passage-averaged velocities and the pressure coefficients shows that the mixing in the downstream regions away from the hub and annulus walls is dominated by wake diffusion. In regions away from the walls, the radial mixing is predominantly caused by the transport of mass, momentum, and energy by the radial component of velocity in the wake.

Experimental and Numerical Investigation of Flow Characteristics Near Casing in an Axial Flow Compressor Rotor at Stable and Stall Inception Conditions

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Yanhui Wu ◽  
Junfeng Wu ◽  
Gaoguang Zhang ◽  
Wuli Chu
Keyword(s):  
Flow Field ◽  
Flow Characteristic ◽  
Flow Characteristics ◽  
Axial Flow ◽  
Stall Inception ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Instantaneous Flow Field ◽  
Measured Flow ◽  
Flow Compressor

Casing instantaneous pressure measurements and full-annulus unsteady simulations were undertaken to analyze flow characteristics near casing at stable and stall inception conditions in an axial flow compressor rotor, and the objective was to establish its linkage with the stall inception process. The measured flow characteristic at near-stall stable operating conditions was the appearance of rotating instability (RI), which attributed to the activity of an unsteady flow with varying frequency. A similar flow characteristic was found in the simulated near-stall stable flow conditions, and detailed analyses of instantaneous flow field indicated the formation and activity of tip secondary vortex could be flow mechanism for the appearance of RI as far as nonuniform tip loading distribution in measurements was concerned. The measured flow characteristic before spike emergence was still the activity of RI. However, it was submerged into flow field accompany by the emergence of spike. The simulated stall inception process was similar to that from measurement, and further analyses of instantaneous flow field established the causal linkage between RI and stall inception process for the test rotor.

Inverse Design of Axial-Flow Compressor Blades Using Elastic Surface Algorithm in Subsonic and Transonic Flow Regimes With Separation

2016 ◽  
Author(s):  
M. H. Noorsalehi ◽  
M. Nili-Ahamadabadi ◽  
E. Shirani ◽  
M. Safari
Keyword(s):  
Pressure Distribution ◽  
Transonic Flow ◽  
Design Method ◽  
Axial Flow ◽  
Flow Regimes ◽  
Inverse Design ◽  
Elastic Surface ◽  
Axial Flow Compressor ◽  
Inverse Design Method ◽  
Flow Compressor

In this study, a new inverse design method called Elastic Surface Algorithm (ESA) is developed and enhanced for axial-flow compressor blade design in subsonic and transonic flow regimes with separation. ESA is a physically based iterative inverse design method that uses a 2D flow analysis code to estimate the pressure distribution on the solid structure, i.e. airfoil, and a 2D solid beam finite element code to calculate the deflections due to the difference between the calculated and target pressure distributions. In order to enhance the ESA, the wall shear stress distribution, besides pressure distribution, is applied to deflect the shape of the airfoil. The enhanced method is validated through the inverse design of the rotor blade of the first stage of an axial-flow compressor in transonic viscous flow regime. In addition, some design examples are presented to prove the effectiveness and robustness of the method. The results of this study show that the enhanced Elastic Surface Algorithm is an effective inverse design method in flow regimes with separation and normal shock.

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