Computation of the Flow Field of Transonic Axial Compressor by Steady Arbitrary Lagrangian Eulerian Formulation

2008 ◽  
Author(s):  
Adel Ghenaiet ◽  
Nouredine Djeghri
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Arbitrary Lagrangian Eulerian ◽  
Viscous Effects ◽  
Stability Range ◽  
Transonic Compressor ◽  
Ale Formulation ◽  
Transonic Axial Compressor ◽  
Residual Smoothing

This paper presents a multi-block solver dealing with an inviscid three dimensional compressible flow through a transonic compressor blading. For efficient computations of the 3D time dependant Euler equations, this solver that we have developed has been cast within a stationary ALE ‘Arbitrary Lagrangian Eulerian’. The main contribution of this paper is by consolidating this ALE formulation, to alleviate the shortcomings linked to rotation effects and the mixed relative subsonic–supersonic inlet flow conditions, which are now simply implemented through an absolute subsonic flow velocity. The finite volume based solver is using the central differencing scheme known as JST (Jameson-Schmidt-Turkel). The explicit multistage Runge-Kutta algorithm is used as a pseudo time marching to the steady-state, coupled with two convergence accelerating techniques; the variable local time-stepping and the implicit residual smoothing procedure. The adaptive implicit residual smoothing has extended the stability range of this explicit scheme, and proved to be successful in accelerating the rate of convergence. This code is currently being extended to include viscous effects, where fluxes are discretized based on Green’s theorem. To support this solver, an H type grid generator based on algebraic and elliptic methods has been developed. The segmentation of the complete domain into smaller blocks has provided full topological and geometrical flexibilities. The code was used to compute the flow field of a transonic axial compressor NASA rotor 37, and comparisons between the calculations and some available experimental data under the design speed and part speed, show qualitatively good agreement.

Influence of Unsteady Effects on the Measurements in a Transonic Axial Compressor

1992 ◽  
Vol 114 (3) ◽  
pp. 510-516 ◽  
Author(s):  
J. Paulon ◽  
Zhifang Zhang ◽  
Pingfang Jia ◽  
Jingfei Meng
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Compressor Stage ◽  
Transonic Compressor ◽  
Flow Parameters ◽  
Transonic Axial Compressor ◽  
Unsteady Effects ◽  
Computation Codes ◽  
Interaction Phenomena

Interaction phenomena between rotor and stator are unavoidable in advanced compressors and their effects increase with the performance of the turbomachines. Until now, it was not possible to quantify the interaction effects, but with the development of three-dimensional unsteady computation codes in a complete stage, it is possible to know, in detail, the flow field through the machine and to make evident and to explain the difficulties encountered in measuring the flow parameters. A study has been conducted in this way at ONERA, on an axial transonic compressor stage. The computations have been made with a simulation of the losses; in this manner, the overall computed and measured performances of the compressor are the same. A detailed analysis of the unsteady computation results makes evident, between rotor and stator, large variations of some parameters of the flow as a function of time, but also as a function of the axial and tangential relative position of steady probes and stator blades. Unsteady measurements made on another transonic machine confirm the indications given by these computations.

scholarly journals Influence of Unsteady Effects on the Measurements in a Transonic Axial Compressor

1991 ◽  
Author(s):  
Jacques Paulon ◽  
Zhifang Zhang ◽  
Pingfang Jia ◽  
Jingfei Meng
Keyword(s):  
Flow Field ◽  
Relative Position ◽  
Axial Compressor ◽  
Compressor Stage ◽  
Transonic Compressor ◽  
Flow Parameters ◽  
Transonic Axial Compressor ◽  
Unsteady Effects ◽  
Computation Codes ◽  
Interaction Phenomena

Interaction phenomena between rotor and stator are unavoidable in advanced compressors and their effects increase with the performances of the turbomachines. Until now, it was not possible to quantify the interaction effects, but with the development of 3-D unsteady computation codes in a complete stage, it is possible to know, in detail, the flow field through the machine and to make evident and to explain the difficulties encountered in measuring the flow parameters. A study has been conducted in this way at ONERA, on an axial transonic compressor stage. The computations have been made with a simulation of the losses; in this manner, the overall computed and measured performances of the compressor are the same. A detailed analysis of the unsteady computation results makes evident, between rotor and stator, large variations of some parameters of the flow as a function of time but also as a function of the axial and tangential relative position of steady probes and stator blades. Unsteady measurements made on another transonic machine confirm the indications given by these computations.

Difference in the Working Principle of Axial Slot and Tip Blowing Casing Treatments

2016 ◽  
Author(s):  
André Inzenhofer ◽  
Cyril Guinet ◽  
Andreas Hupfer ◽  
Bernd Becker ◽  
Patrick Grothe ◽  
...  
Keyword(s):  
Flow Field ◽  
Axial Compressor ◽  
Casing Treatment ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Negative Effect ◽  
Working Principle ◽  
Transonic Axial Compressor ◽  
The Difference ◽  
Casing Treatments

Tip blowing and axial slot casing treatments have shown their ability to enhance the stability of a transonic axial compressor with different effects on efficiency. For an effective application of these casing treatments, a good knowledge of the influence of the casing treatment on the rotor flow field is important. There is still a need for more detailed investigations, in order to understand the interaction between the treatment and the near casing 3D flow field. For transonic compressor rotors this interaction is more complex, as super- and subsonic flow regions alternate while interacting with the casing treatment. In the present study, an axial slot and a tip blowing casing treatment, which have been developed and optimized for the same tip critical transonic axial compressor rotor (reference rotor) by Streit et al. [1] and Guinet et al. [2], are subject of the investigation. Both casing treatment types showed their capabilities to enhance the compressor stability without losing by means of CFD simulations. Since the higher compressor stability allows a higher blade loading, Streit et al. reduced the blade number of the rotor. Thus, the efficiency was increased due to the reduction of friction losses. However, applying the tip blowing casing treatment to the reduced rotor shows a negative effect on the efficiency. Both casing treatment types recirculate flow from a downstream to an upstream location of the rotor and reinject it to enhance the near casing flow field. Although the working principle of the two casing treatment types are similar, the transfer of the casing treatments from the reference to the reduced rotor show different trends in efficiency. Therefore, the effect of recirculation cannot explain the difference in efficiency. Hence, applying axial slots must include additional flow features, compared to recirculation channels. Compensating effects as in circumferential groove casing treatments and other flow interactions between the near casing flow field and the slot flow are considered. These additional mechanisms of the axial slot casing treatment will be identified and isolated by comparing the two different casing treatment types. The numerical simulations are carried out on a 1.5 stage transonic axial compressor using URANS simulations.

Experimental Study of the Flow Field Within a Transonic Axial Compressor Rotor by Laser Velocimetry and Comparison With Through-Flow Calculations

1978 ◽  
Vol 100 (2) ◽  
pp. 279-286 ◽  
Author(s):  
R. J. Dunker ◽  
P. E. Strinning ◽  
H. B. Weyer
Keyword(s):  
Flow Field ◽  
Pressure Ratio ◽  
Analytical Data ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Compressor Rotor ◽  
Through Flow ◽  
Equivalent Mass ◽  
Transonic Axial Compressor ◽  
Design Speed

The flow field ahead, within, and behind the rotor of a transonic axial compressor designed for a total pressure ratio of 1.51 at a relative tip Mach number of 1.4 has been studied in detail using an advanced laser velocimeter. The tests were carried out at 70 and 100 percent design speed (20,260 rpm) and equivalent mass flows corresponding to the point of maximum isentropic efficiency. The tests yielded quite complete data on the span- and gap-wise velocity profiles, on the three-dimensional shock waves in and outside of the rotor blade channels, and on the blade wakes. Some of the experimental results will be submitted, discussed, and compared to corresponding analytical data of a through-flow calculation. The comparison reveals considerable discrepancies inside the blade row between the two-dimensional calculation and the experiments primarily due to the loss and deviation correlations used, as well as to the distribution of losses and flow angles inside the blade channels.

Analysis of the Interrow Flow Field Within a Transonic Axial Compressor: Part 2—Unsteady Flow Analysis

2000 ◽  
Vol 123 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Xavier Ottavy ◽  
Isabelle Tre´binjac ◽  
Andre´ Vouillarmet
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Leading Edge ◽  
Rotor Blades ◽  
Time Averaging ◽  
Order Of Magnitude ◽  
Transonic Axial Compressor

An analysis of the experimental data, obtained by laser two-focus anemometry in the IGV-rotor interrow region of a transonic axial compressor, is presented with the aim of improving the understanding of the unsteady flow phenomena. A study of the IGV wakes and of the shock waves emanating from the leading edge of the rotor blades is proposed. Their interaction reveals the increase in magnitude of the wake passing through the moving shock. This result is highlighted by the streamwise evolution of the wake vorticity. Moreover, the results are analyzed in terms of a time-averaging procedure and the purely time-dependent velocity fluctuations that occur are quantified. It may be concluded that they are of the same order of magnitude as the spatial terms for the inlet rotor flow field. That shows that the temporal fluctuations should be considered for the three-dimensional rotor time-averaged simulations.

scholarly journals Laser Two-Focus Anemometry Investigation of the Flow Field Within a Supersonic Axial Compressor Rotor

1990 ◽  
Author(s):  
Isabelle Trebinjac ◽  
André Vouillarmet
Keyword(s):  
Flow Field ◽  
Comprehensive Evaluation ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Viscous Effects ◽  
Compressor Rotor ◽  
High Pressure Compressor ◽  
Good Agreement

Laser anemometer measurements have been performed within and downstream of a supersonic single-stage high-pressure compressor. At design point and with standard upstream conditions the maximum relative Mach number varies from 1.3 at the tip to 1.1 at the hub. The stage total pressure ratio is 1.84 and the specific mass flow 180 kg/s/m2. The laser two-focus anemometer has been completely designed in the Laboratory; its originality being the use of a counting technique instead of the classical multichannel analyzer one. The data acquisition and reduction procedures are presented here. A comprehensive evaluation of the global flow-field is in the scope of this paper. For that, the intra-blade flow field is described and the shock pattern is discussed. Furthermore, the experimental results are compared with both inviscid and viscous three-dimensional numerical simulations. The viscous computation is based on the Navier-Stokes solution using a mixing length turbulence model. The good agreement observed in this last case shows off the necessity of taking into account the viscous effects in a supersonic compressor flow calculation.

Numerical investigation of the axial compressor performance with inlet distortions

2017 ◽  
Vol 232 (8) ◽  
pp. 1434-1441
Author(s):  
ZX Liu ◽  
HZ Diao ◽  
XC Zhu ◽  
ZH Du
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Body Force ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Force Model ◽  
Transonic Compressor ◽  
High Pressure Ratio ◽  
Compressor Performance

In this paper, a three-dimensional body force model for predicting compressor performance and stability is implemented in the Ansys CFX. The influence of the blade rows on the flow field is represented by the source terms of CFX-solver equation. At first, a high-speed and high-pressure-ratio transonic compressor with the clean inlet is investigated. The overall performance and the flow fields are in agreement well with those of the experimental date, so the model is reliable and correct. Then, the effects of the circumferential distortions in the inlet total pressure and the total temperature on the compressor performance and flow field are also illustrated, respectively. In summary, the proposed body force model is suitable to investigate the flow field of the compressor with the inlet distortions.

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.

Flow Field Unsteadiness in the Tip Region of a Transonic Compressor Rotor

1997 ◽  
Vol 119 (1) ◽  
pp. 122-128 ◽  
Author(s):  
S. L. Puterbaugh ◽  
W. W. Copenhaver
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Vortex Interaction ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Operating Points

An experimental investigation concerning tip flow field unsteadiness was performed for a high-performance, state-of-the-art transonic compressor rotor. Casing-mounted high frequency response pressure transducers were used to indicate both the ensemble averaged and time varying flow structure present in the tip region of the rotor at four different operating points at design speed. The ensemble averaged information revealed the shock structure as it evolved from a dual shock system at open throttle to an attached shock at peak efficiency to a detached orientation at near stall. Steady three-dimensional Navier Stokes analysis reveals the dominant flow structures in the tip region in support of the ensemble averaged measurements. A tip leakage vortex is evident at all operating points as regions of low static pressure and appears in the same location as the vortex found in the numerical solution. An unsteadiness parameter was calculated to quantify the unsteadiness in the tip cascade plane. In general, regions of peak unsteadiness appear near shocks and in the area interpreted as the shock-tip leakage vortex interaction. Local peaks of unsteadiness appear in mid-passage downstream of the shock-vortex interaction. Flow field features not evident in the ensemble averaged data are examined via a Navier-Stokes solution obtained at the near stall operating point.

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