scholarly journals Computation of Secondary Flows in an Axial Flow Compressor Including Inviscid and Viscous Flow Computation

1984 ◽  
Author(s):  
Francis Leboeuf
Keyword(s):  
Boundary Layer ◽  
Viscous Flow ◽  
Axial Flow ◽  
Inviscid Flow ◽  
Secondary Flows ◽  
Computational Method ◽  
Flow Computation ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Highly Loaded

A computational method for secondary flows in a compressor has been extended to treat stalled flows. An integral equation is used which simulates the inviscid flow at the wall, under the viscous flow influence. We present comparisons with experimental results for a 2D stalled boundary layer, and for the secondary flow in a highly loaded stator of an axial flow compressor.

Highly-Loaded Low-Reaction Boundary Layer Suction Axial Flow Compressor

2007 ◽  
Author(s):  
Songtao Wang ◽  
Xiaoqing Qiang ◽  
Weichun Lin ◽  
Guotai Feng ◽  
Zhongqi Wang
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Design Concept ◽  
Axial Flow Compressor ◽  
Boundary Layer Suction ◽  
High Pressure Ratio ◽  
Flow Compressor ◽  
Highly Loaded

In order to design high pressure ratio and highly loaded axial flow compressor, a new design concept based on Highly-Loaded Low-Reaction and boundary layer suction was proposed in this paper. Then the concept’s characteristics were pointed out by comparing with the MIT’s boundary layer suction compressor. Also the application area of this design concept and its key technic were given out in this paper. Two applications were carried out in order to demonstrate the concept. The first application was to redesign a low speed duplication-stage axial flow compressor into a single stage. The second one was a feasibility analysis to decrease an 11 stage axial compressor’s stage count to 7 while not changing its aerodynamic performance. The analysis result showed that the new design concept is feasible and it can be used on high pressure stage of the aero-engine, compressor of ground gas turbine (except the transonic stage) and high total pressure ratio blower.

scholarly journals Experimental Study and Theoretical Prediction of Secondary Flows in a Transonic Axial Flow Compressor

1982 ◽  
Author(s):  
F. Leboeuf ◽  
F. Bario ◽  
G. Boris ◽  
K. D. Papailiou
Keyword(s):  
Secondary Flow ◽  
Vortex Motion ◽  
Axial Compressor ◽  
Axial Flow ◽  
Inviscid Flow ◽  
Secondary Flows ◽  
Tip Clearance ◽  
Axial Distance ◽  
Axial Flow Compressor ◽  
Flow Compressor

Detailed time-mean measurements have been realized on a transonic axial flow compressor. Flow quantities in the secondary flow regions have been obtained. The purpose of this paper is to present some essential features which drive the secondary following development in axial compressor among others, the strong influence of secondary vortex motion on the energy transfer between the flow and the blading is displayed. Also, we study the effect of tip clearance and axial distance between blade row. A secondary flow model is used for comparisons with theoretical computations. Very good comparisons have been obtained which show the validity of the theoretical model, in particular, the decomposition of the secondary flow into a viscous part and a vortical part, using an inviscid flow as a basis.

A New Design Concept of Highly-Loaded Axial Flow Compressor by Applying Boundary Layer Suction and 3D Blade Technique

2008 ◽  
Author(s):  
Xiaoqing Qiang ◽  
Songtao Wang ◽  
Weichun Lin ◽  
Zhongqi Wang
Keyword(s):  
Boundary Layer ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Boundary Layer Separation ◽  
Design Concept ◽  
Turning Angle ◽  
Boundary Layer Suction ◽  
Layer Separation ◽  
Flow Compressor ◽  
Highly Loaded

A new design concept of highly-loaded axial flow compressor by applying boundary layer suction and 3D blade technique was proposed in this paper. The basic idea of this design concept was that low reaction was adopted as while as increasing the rotor’s geometry turning angle, so that the boundary layer separation of a rotor could be eliminated and the rotor was kept working in high efficiency. This design concept would greatly increase the stator’s geometry turning angle, so boundary layer suction on stator cascades was adopted in order to restrain the boundary layer separation. In some situations, 3D blade technique was also applied in order to control the boundary layer separation more efficiently. The advantages of the above design concept were: the compressor’s pressure ratio was increased remarkably; boundary layer suction was only adopted in stator cascades so as to reduce the complexity of boundary layer suction structure. The key techniques of the new design concept were also explained in this paper. In order to increase the compressor’s pressure ratio, the geometry turning angle of rotor was increased greatly, and the rotor inlet was prewhirled to reduce the rotor’s reaction so as to restrain the rotor’s boundary separation. Boundary layer suction was carried out in the stator cascades (mainly on suction side), hub and shroud in order to control the flow separation. 3D blade technique could be adopted if necessary. The limitation of the application of this design concept was also pointed out through the analysis of the Mach number at rotor inlet, the prewhirl angle of rotor, the work distribution along span wise and the control method of stator separation. Numerical simulation was carried out on a single low-reaction compressor stage with IGV in order to demonstrate the new design concept. By using boundary layer suction and 3D blade technique, the energy loss in stator cascades was greatly reduced and the whole stage’s isentropic efficiency was about 90%. The low-reaction stage’s aerodynamic load was double than conventional design. The boundary layer separation could be effectively controlled by proper combination of boundary layer suction and bowed or twisted blade. The numerical result proved that the new design concept was feasible and had a wide application area.

Boundary-Layer Development on an Axial-Flow Compressor Stator Blade

1978 ◽  
Vol 100 (2) ◽  
pp. 287-292 ◽  
Author(s):  
R. L. Evans
Keyword(s):  
Boundary Layer ◽  
Axial Flow ◽  
Layer Growth ◽  
Ensemble Averaging ◽  
Mean Velocity ◽  
Axial Flow Compressor ◽  
Boundary Layer Development ◽  
Stator Blade ◽  
Flow Compressor ◽  
Layer Development

The boundary layer on an axial-flow compressor stator blade has been measured using an ensemble-averaging technique. Although the mean velocity profiles appear to indicate fully developed turbulent flow, ensemble-averaged instantaneous profiles show the boundary layer to be highly unsteady and transitional over much of the blade chord. At a given chordwise position, variations in boundary-layer thickness with time of up to 150 percent were recorded. When compared to boundary-layer development on a similar blade in a two-dimensional cascade the stator blade boundary-layer growth was found to be much greater. The results indicate that extreme caution should be used in attempting to predict blade boundary-layer development from cascade test results or steady calculation procedures.

Investigations on Stator Hub End Losses and its Control in an Axial Flow Compressor

2014 ◽  
Author(s):  
Kurian K. George ◽  
S. N. Agnimitra Sunkara ◽  
Jubin Tom George ◽  
Melvin Joseph ◽  
A. M. Pradeep ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Axial Flow ◽  
Separated Flow ◽  
Tip Clearance ◽  
Axial Flow Compressor ◽  
Large Vortex ◽  
Stator Blade ◽  
Twisted Blade ◽  
Flow Compressor ◽  
Highly Loaded

In an axial flow compressor, the presence of separated flow near the hub-end of a stator would result in an overall loss in the performance. In the present paper, stator hub-stall is attempted to be eliminated for a high hub-tip ratio (0.8) axial flow compressor stage consisting of a highly loaded rotor and stator. Numerical and experimental studies on an untreated straight stator (straight-stacked, twisted) blade show a large vortex near its hub. The large vortex is attempted to be reduced by modifying the present blade by (i) providing an additional twist at the hub-end of the stator blade (ii) providing a hub-clearance (a cantilevered blade fixed from the casing). The straight (untreated) stator, hub-end-bend version and the hub-clearance version are studied for two different rotor-tip clearances. Detailed computational analysis of the variation of hub-clearance at a fixed rotor-tip clearance is also carried out. Throughout the study, experiments are carried out on the above discussed different stator (untreated & hub-treated) configurations, in combination with the same rotor, at a fixed rotor-tip clearance. The studies show that the flow conditions are improved near the hub of the highly loaded stator blade both by the hub-end-bend design and by the hub-clearance provided.

Effect of Turbulence Model on the Prediction of Performance and Span-Wise Mixing in High-Speed Highly-Loaded Multi-Stage Axial-Flow Compressor

2019 ◽  
Author(s):  
Takashi Goto ◽  
Tetsuya Oshio ◽  
Naoki Tani ◽  
Mizuho Aotsuka ◽  
Guillaume Pallot ◽  
...  
Keyword(s):  
Flow Field ◽  
Turbulence Model ◽  
High Speed ◽  
Axial Flow ◽  
Weno Scheme ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Radial Profiles ◽  
Flow Compressor ◽  
Highly Loaded

Abstract Despite significant advancements in computational power and various numerical modeling in past decades, flow simulation of a multi-stage axial-flow compressor is still one of the most active areas of research, for it is the critical component in engine performance and operability, and there are so many elements that need to be looked into to predicting correct matching of the stages and accurate flow distribution inside the machine. Modeling unsteadiness, both deterministic and random types, and real geometries are among the most important features to be considered in such prediction. The authors have conducted in their previous studies a series of unsteady RANS (URANS) simulations of a 6.5-stage high-speed highly-loaded axial-flow compressor, and explored many unsteady effects as well as effects of real geometries such as Variable Stator Vane (VSV) clearance and inter-stage seal leakage flow on the compressor performance. However, all the analyses failed to predict correct stage matching, total pressure and temperature radial profiles, or mass-flow with adequate accuracies. In the present study, an Improved Delayed Detached Eddy Simulation (IDDES) with SST k-omega model is applied to the simulation of the same compressor configuration at aerodynamic design point. Fifth-order WENO scheme is employed for improved spatial accuracy to suppress significant increase in mesh size. Total number of mesh points are over 400 million for 1/10th sector model. Computations are ensemble averaged for 20 sector passage. Computed overall performance and flow field are compared with the compressor rig test data. The predictions of inter-stage total temperature radial profiles are noticeably improved over the URANS with the same mesh, discretization scheme and eddy turbulence model. Good comparison with the rig data indicates the current simulation is properly capturing the span-wise mixing phenomena. Unsteady flow field are compared between IDDES and URANS to locate the cause for the enhanced mixing. It is shown that components of Reynolds stress responsible for radial diffusion and anisotropic features are intensified in the tip leakage vortex at the rotor exit for the IDDES.

The effect of variable stator on performance of a highly loaded tandem axial flow compressor stage

2016 ◽  
Vol 25 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Hamzeh Eshraghi ◽  
Masoud Boroomand ◽  
Abolghasem M. Tousi ◽  
Mohammad Toude Fallah ◽  
Ali Mohammadi
Keyword(s):  
Axial Flow ◽  
Compressor Stage ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Variable Stator ◽  
Highly Loaded
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