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.

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.

Combined Effects of Forward Sweep and Tip Clearance on the Performance of Axial Flow Compressor Stage

2009 ◽  
Author(s):  
P. V. Ramakrishna ◽  
M. Govardhan
Keyword(s):  
Total Pressure ◽  
Axial Compressor ◽  
Axial Flow ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Numerical Work ◽  
Low Speed ◽  
Operating Range ◽  
Axial Flow Compressor ◽  
Flow Compressor

There are a number of performance indices for a turbomachine on the basis of which its strength is evaluated. In the case of axial compressors, pressure ratio, efficiency and stall margin are few such indices which are of major concern in the design phase as well as in the evaluation of performance of the machine. In the process of improving the blade design, 3D blade stacking, where the aerofoil sections constituting the blade are moved in relation to the flow. Tilting the blade sections to the flow direction (blade sweep) would increase the operating range of an axial compressor due to modifications in the pressure and velocity fields on the suction surface. On the other hand, blade tip gap, though finite, has great influence on the performance of a turbomachine. The present work investigates the combined effect of these two factors on various flow characteristics in a low speed axial flow compressor. The objective of the present paper is thereby confined to study the collective effects of sweep and tip clearance without attempting to suggest an outright new design. In the present numerical work, the performance of Tip Chordline Sweeping (TCS) and Axial Sweeping (AXS) of low speed axial compressor rotor blades are studied. For this, 15 computational domains were modeled for five rotor sweep configurations and three different clearance levels for each rotor. Through the results, 20°AXS rotor is found to be distinctive among all the rotors with highest pressure rise, higher operating range and less tip clearance loss characteristics. TCS rotors produced improved total pressure rise at the low flow coefficients when the tip gap is increased. Hence there is a chance that an “optimum” tip gap exists for the TCS rotors in terms of total pressure coefficient and operating range, while AXS rotors are at their best with the minimum possible clearance.

scholarly journals Effect of Circumferential Single Casing Groove Location on the Flow Stability under Tip-Clearance Effect in a Transonic Axial Flow Compressor Rotor

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6143
Author(s):  
Xiaoxiong Wu ◽  
Bo Liu ◽  
Botao Zhang ◽  
Xiaochen Mao
Keyword(s):  
Control Mechanism ◽  
Incidence Angle ◽  
Axial Flow ◽  
Flow Stability ◽  
Tip Clearance ◽  
Tip Leakage Flow ◽  
Flow Angle ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor

Numerical simulations have been performed to study the effect of the circumferential single-grooved casing treatment (CT) at multiple locations on the tip-flow stability and the corresponding control mechanism at three tip-clearance-size (TCS) schemes in a transonic axial flow compressor rotor. The results show that the CT is more efficient when its groove is located from 10% to 40% tip axial chord, and G2 (located at near 20% tip axial chord) is the best CT scheme in terms of stall-margin improvement for the three TCS schemes. For effective CTs, the tip-leakage-flow (TLF) intensity, entropy generation and tip-flow blockage are reduced, which makes the interface between TLF and mainstream move downstream. A quantitative analysis of the relative inlet flow angle indicates that the reduction of flow incidence angle is not necessary to improve the flow stability for this transonic rotor. The control mechanism may be different for different TCS schemes due to the distinction of the stall inception process. For a better application of CT, the blade tip profile should be further modified by using an optimization method to adjust the shock position and strength during the design of a more efficient CT.

Numerical Investigations of the Coupled Flow Through a Subsonic Compressor Rotor and Axial Skewed Slot

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Xingen Lu ◽  
Wuli Chu ◽  
Junqiang Zhu ◽  
Yangfeng Zhang
Keyword(s):  
Axial Flow ◽  
Tip Clearance ◽  
Stall Margin ◽  
Tip Clearance Flow ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Clearance Flow ◽  
Flow Through ◽  
Flow Compressor

In order to advance the understanding of the fundamental mechanisms of axial skewed slot casing treatment and their effects on the subsonic axial-flow compressor flow field, the coupled unsteady flow through a subsonic compressor rotor and the axial skewed slot was simulated with a state-of-the-art multiblock flow solver. The computational results were first compared with available measured data, that showed the numerical procedure calculates the overall effect of the axial skewed slot correctly. Then, the numerically obtained flow fields were interrogated to identify the physical mechanism responsible for improvement in stall margin of a modern subsonic axial-flow compressor rotor due to the discrete skewed slots. It was found that the axial skewed slot casing treatment can increase the stall margin of subsonic compressor by repositioning of the tip clearance flow trajectory further toward the trailing of the blade passage and retarding the movement of the incoming∕tip clearance flow interface toward the rotor leading edge plane.

Three-Dimensional Flow and Mixing in an Axial Flow Compressor With Different Rotor Tip Clearances

1992 ◽  
Vol 114 (3) ◽  
pp. 675-685 ◽  
Author(s):  
A. Goto
Keyword(s):  
Velocity Fluctuation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Flow Fields ◽  
Tip Clearance ◽  
Small Scale ◽  
Three Dimensional Flow ◽  
Axial Flow Compressor ◽  
Dimensional Flow ◽  
Flow Compressor

The effect of difference in rotor tip clearance on the mean flow fields and unsteadiness and mixing across a stator blade row were investigated using hot-wire anemometry, pressure probes, flow visualization, and the ethylene tracer-gas technique on a single-stage axial flow compressor. The structure of the three-dimensional flow fields was discussed based on results of experiments using the 12-orientation single slanted hotwire technique and spectrum analysis of velocity fluctuation. High-pass filtered measurements of turbulence were also carried out in order to confirm small-scale velocity fluctuation, which is more realistically referred to as turbulence. The span-wise distribution of ethylene gas spreading, estimated by the measured small-scale velocity fluctuation at the rotor exit, agreed quite well with that which was experimentally measured. This fact suggests the significant role of turbulence, generated within the rotor, in the mixing process across the downstream stator. The value of the maximum mixing coefficient in the tip region was found to increase linearly as the tip clearance became enlarged, starting from the value at midspan.

1118 Effect of Tip Clearance on Rotating Stall Inception in an Axial Flow Compressor Rotor

2009 ◽  
Vol 2009 (0) ◽  
pp. 377-378 ◽  
Author(s):  
Hiroaki KIKUTA ◽  
Masato FURUKAWA ◽  
Satoshi GUNJISHIMA ◽  
Kenichiro IWAKIRI ◽  
Takuro KAMEDA
Keyword(s):  
Axial Flow ◽  
Rotating Stall ◽  
Tip Clearance ◽  
Stall Inception ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor

2415 Effect of Tip Clearance on Structure of Rotating Stall Cell in an Axial Flow Compressor Rotor

2006 ◽  
Vol 2006.2 (0) ◽  
pp. 149-150
Author(s):  
Sho BONKOHARA ◽  
Ken-ichiro IWAKIRI ◽  
Ryusuke OHTAGURO ◽  
Yasuhiro SHIBAMOTO ◽  
Masato FURUKAWA
Keyword(s):  
Axial Flow ◽  
Rotating Stall ◽  
Tip Clearance ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor

Effects of tip clearance size on the unsteady flow behaviors and performance in a counter-rotating axial flow compressor

2017 ◽  
Vol 233 (3) ◽  
pp. 1059-1070 ◽  
Author(s):  
Xiaochen Mao ◽  
Bo Liu ◽  
Hang Zhao
Keyword(s):  
Unsteady Flow ◽  
Incidence Angle ◽  
Axial Flow ◽  
Leading Edge ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Axial Flow Compressor ◽  
Flow Compressor

This paper presents the studies performed to better understand the effects of increased tip clearance size on the unsteady flow behaviors and overall performance under the rotor–rotor interaction environment in a counter-rotating axial flow compressor. The investigation method is based on the three-dimensional unsteady Reynolds-averaged Navier–Stokes simulations. The results show that the intensified tip leakage flow in front rotor (R1) caused by the increased tip clearance size will lead to the growth of incoming incidence angle near the tip of the rear rotor (R2). The increasing of double leakage flow range plays a significant role in the sensitivity of the efficiency to tip clearance size and its extent is enlarged gradually with the increase of tip clearance size. As the tip clearance size is increased to 1.5τ (τ represents the designed tip clearance size) from 0.5τ, the results of the fast Fourier transform for the static pressure near blade tip show that two other new fluctuating frequency components appear due to the happening of tip leakage flow self-unsteadiness in R1 and R2, respectively. Additionally, the fluctuating strength near the tip in R2 is significantly increased. However, both the overall fluctuation in R1 caused by the potential effect from downstream and the oscillation in the hub corner on the pressure side of R2 are decreased obviously. The relative inflow angle tends to increase when the incoming wakes and tip leakage flow from R1 encounter the blade leading edge of R2, which leads to the result that the trajectory of tip leakage flow is shifted more upstream.

Numerical Studies on Effect of Stepped Tip Clearance Height on the Performance of Single Stage Transonic Axial Flow Compressor

2013 ◽  
Author(s):  
Pritam Batabyal ◽  
Dilipkumar B. Alone ◽  
S. K. Maharana
Keyword(s):  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Flow ◽  
Single Stage ◽  
Tip Clearance ◽  
Baseline Model ◽  
Axial Flow Compressor ◽  
Design Speed ◽  
Flow Compressor

This paper presents a numerical case study of various stepped tip clearances and their effect on the performance of a single stage transonic axial flow compressor, using commercially available software ANSYS FLUENT 14.0. A steady state, implicit, three dimensional, pressure based flow solver with SST k-Ω turbulence model has been selected for the numerical study. The stepped tip clearances have been compared with the baseline model of zero tip clearance at 70% and 100 % design speed. It has been observed that the compressor peak stage efficiency and maximum stage pressure ratio decreases as the tip clearances in the rear part are increased. The stall margin also increases with increase in tip clearance compared to the baseline model. An ‘optimum’ value of stepped tip clearance has been obtained giving peak stage compressor performance. The CFD results have been validated with the earlier published experimental data on the same compressor at 70% design speed.

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