scholarly journals The Use of Experimental Interstate Data for Matching the Performance of Axial Compressor Stages Having Variable-Setting-Angle Blade Rows

1976 ◽  
Author(s):  
L. E. Brown
Keyword(s):  
Rotor Blade ◽  
Axial Compressor ◽  
Axial Flow ◽  
Performance Characteristics ◽  
Test Rig ◽  
Axial Flow Compressor ◽  
Component Test ◽  
Experimental Tool ◽  
Angle Blade ◽  
Flow Compressor

Stage performance characteristics provide a powerful analytic tool for experimentally matching the stages and blade rows of an axial-flow compressor, while the variable stage compressor component test rig provides a most powerful experimental tool for developing compressors. This paper describes: Why and how the stage characteristics “normalized” to correct them for changes of stator setting angles, how these normalized characteristics can be fully defined for every stage; and how these characteristic can point the way to a well-matched configuration of setting angles. In addition, it proposes methods for distinguishing between the stall of rotors and stators and for normalizing the characteristics of stages with variable-setting rotor blade rows.

Influence of Rain Ingestion on the Endwall Treatment in an Axial Flow Compressor

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Jichao Li ◽  
Juan Du ◽  
Mingzhen Li ◽  
Feng Lin ◽  
Hongwu Zhang ◽  
...  
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Pressure Rise ◽  
Water Film ◽  
Stall Margin ◽  
Axial Flow Compressor ◽  
Water Ingestion ◽  
Blade Row ◽  
Flow Compressor ◽  
The Stability

The effects of water ingestion on the performance of an axial flow compressor are experimentally studied with and without endwall treatment. The background to the work is derived from the assessment of airworthiness for an aero-engine. The stability-enhancing effects with endwall treatments under rain ingestion are not previously known. Moreover, all the endwall treatments are designed under dry air conditions in the compressor. Water ingestion at 3% and 5% relative to the design mass flow proposed in the airworthiness standard are applied to initially investigate the effects on the performance under smooth casing (SC). Results show that the water ingestions are mainly located near the casing wall after they move through the rotor blade row. The pressure rise coefficient increases, efficiency declines, and torque increases under the proposed water ingestion. The increase of the inlet water increases the thickness of the water film downstream the rotor blade row and aggravates the adverse effects on the performances. Subsequently, three endwall treatments, namely circumferential grooves, axial slots, and hybrid slots–grooves, are tested with and without water ingestion. Compared with no water ingestion, the circumferential grooves basically have no resistance to the water ingestion. The axial slots best prevent the drop of the pressure rise coefficient induced by water ingestion, and hybrid slots–grooves are the second-best place owing to the contribution of the front axial slots. Therefore, the hybrid slots–grooves can not only extend the stall margin with less efficiency penalty compared with axial slots, but also prevent rain ingestion from worsening the compressor performance.

Aerodynamic Design and Performance of Five-Stage Transonic Axial-Flow Compressor

1961 ◽  
Vol 83 (3) ◽  
pp. 303-320 ◽  
Author(s):  
Karl Kovach ◽  
D. M. Sandercock
Keyword(s):  
Research Work ◽  
Axial Flow ◽  
Performance Characteristics ◽  
Research Center ◽  
Aerodynamic Design ◽  
Axial Flow Compressor ◽  
Turbojet Engine ◽  
And Performance ◽  
Flow Compressor ◽  
Work Done

A five-stage axial-flow compressor with all rotors operating with transonic relative inlet Mach numbers was designed as a research vehicle at the Lewis Research Center in 1952. The compressor was designed and tested as a component of a turbojet engine. This paper summarizes the research work done on this compressor including the aerodynamic design and detailed performance characteristics.

Water Film Formation on an Axial Flow Compressor Rotor Blade

2008 ◽  
Author(s):  
Theoklis Nikolaidis ◽  
Periclis Pilidis ◽  
J. A. Teixeira ◽  
V. Pachidis
Keyword(s):  
Rotor Blade ◽  
Guide Vane ◽  
Axial Flow ◽  
Water Film ◽  
Inlet Guide Vane ◽  
Computational Domain ◽  
Axial Flow Compressor ◽  
Water Ingestion ◽  
Compressor Rotor ◽  
Flow Compressor

A numerical approach was used to evaluate the liquid water film thickness and its motion on an axial flow compressor rotor blade under water ingestion conditions. By post-processing blading data and using computer programs to create the blades and their computational grid, the global computational domain of the first stage of an axial flow compressor was built. The flow field within the domain was solved by CFX-Tascflow, which is a commercial CFD code commonly used in turbomachinery. The computational domain consists of an extended inlet, an inlet guide vane, a rotor and a stator blade. Having solved the flow field at Design Point, the inlet guide vane blade was re-positioned to account for changes in idle speed. At that speed, the effects of water ingestion are expected to be more significant on gas turbine engine performance. Several cases with water ingestion were studied, changing parameters like water mass and compressor rotational speed. A FORTRAN computer program was created to calculate the water film height and speed. The extra torque needed by the compressor to keep running at the same rotational speed, was also calculated. The considerable increase in torque was confirmed by experimental observations according to which water ingestion had a detrimental effect on gas turbine operation.

Flow Fields in an Axial Flow Compressor During Four-Quadrant Operation

2013 ◽  
Author(s):  
Andrew Gill ◽  
Theodor W. von Backström ◽  
Thomas M. Harms ◽  
Dwain Dunn
Keyword(s):  
Flow Direction ◽  
Tangential Velocity ◽  
Axial Compressor ◽  
Axial Flow ◽  
Pressure Rise ◽  
Flow Fields ◽  
Time Dependent ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor

It has been shown in previous investigations that when all combinations of both positive and negative direction of rotation and flow direction are allowed in operating a multistage axial flow compressor, the operating point may be in any of the four quadrants of the pressure rise versus flow characteristic. The present paper is the first discussion of the flow field of all possible modes of operation of an axial flow compressor. During the present study interstage time dependent hot film velocity measurements and five hole pneumatic probe measurements were combined with steady and time dependent CFD solutions to investigate the flow fields in the three-stage axial compressor. Results are presented in terms of mean-line velocity triangles, mean stream surface plots, mid-span radial velocity contours right through the compressor, rotor-downstream radial distributions of axial and tangential velocity, stator-downstream axial velocity contours and mid-span entropy contours through the compressor. Main flow features are pointed out and discussed. The study was instigated in an effort to understand possible accident scenarios in a three-shaft closed cycle nuclear powered helium gas turbine.

The Effect of Rotor Blade Speed to the Best Efficiency Point of Single Stage Axial Flow Compressor

2010 ◽  
Author(s):  
Mohamad Firdaus Sukri ◽  
Faizil Wasbari ◽  
Shafizal Mat ◽  
M. A. Wahid ◽  
S. Samion ◽  
...  
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Single Stage ◽  
Axial Flow Compressor ◽  
Flow Compressor

Flow Analysis of Axial Compressor AV63-15 Variable Stator Simulation

2012 ◽  
Vol 532-533 ◽  
pp. 474-478
Author(s):  
Wei Hua Cheng ◽  
Mian Chang Li ◽  
Chuan Peng Li
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Operating Conditions ◽  
Axial Flow Compressor ◽  
Air Supply ◽  
The Difference ◽  
And Performance ◽  
Flow Compressor

This paper conducts numerical simulation to a 15-stage civil axial flow compressor and obtains its main parameters distribution and performance curve by a full three-dimensional viscid flow computation software. The computation result indicates that, the developed axial flow compressor meets the anticipated design requirements, and satisfies the customers’ indicators. Under the designed compression ratio, the difference between the maximum air supply quantity in summer and the minimum air supply quantity in winter is 22%. By comparing the operating conditions and data analysis, obtained the change trend of axial velocity, static pressure and temperature, and Ma, and discovered that, under opening of 48° and outlet back pressure of 550KPa, flow separation occurred on the section of machine set close to hud, which indicated that operating condition was close to surging condition.

Experimental and numerical investigation of a subsonic compressor with bend-skewed slot-casing treatment

2006 ◽  
Vol 220 (12) ◽  
pp. 1785-1796 ◽  
Author(s):  
X Lu ◽  
W Chu ◽  
Y Zhang ◽  
J Zhu
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Efficiency Gain ◽  
Stall Margin ◽  
Blade Passage ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor ◽  
Isentropic Efficiency

On the basis of the test results of discrete axial and blade angle slot casing treatment, a new type of casing treatment was designed for a subsonic axial flow compressor rotor by optimizing various geometry parameters. To obtain a wide operating range and to minimize penalties in terms of isentropic efficiency, seven compressor configurations incorporating casing treatments of 0, 16.6, 33.3, 50, 66.6, 83.3, and 100 per cent rotor exposures were experimentally investigated. The results showed that significant improvements in stall margin are possible in all exposures and insignificant isentropic efficiency sacrifices are recorded in some exposures. Nearly 21.43 per cent stall margin improvement in terms of the corrected mass flow-rate was achieved with 33.3 per cent rotor blade tip axial chord exposure. The compressor built with 16.6 per cent rotor exposure was the best configuration in terms of maximum isentropic efficiency gain. The second issue of the paper was to offer a contribution to the understanding of the physical mechanism by which bend-skewed slot-casing treatment improves stall margin under subsonic conditions. By applying a concept similar to ‘Domain scaling’ approach (as often used in multistage turbomachinery flow-fields) to the interface between the rotor blade passage and end-wall treatments, a time-dependent three-dimensional numerical simulation was performed for the subsonic axial-flow compressor rotor with bend-skewed slot-casing treatment. The numerical results agreed well with the available experimental results. Detailed analyses of the coupled flow through bend-skewed slot-casing treatment and rotor blade passage under subsonic conditions led to some preliminary conclusions as to the flow physics involved in the stall margin improvements afforded by the use of bend-skewed slot-casing treatment.

Growth of a Perturbation in an Axial Flow Compressor

1979 ◽  
Vol 101 (1) ◽  
pp. 87-94 ◽  
Author(s):  
J. Fabri
Keyword(s):  
Angular Velocity ◽  
Initial Perturbation ◽  
Axial Compressor ◽  
Axial Flow ◽  
Time Dependent ◽  
Perturbation Amplitude ◽  
Axial Flow Compressor ◽  
Linearized Theory ◽  
Flow Compressor ◽  
Multistage Axial Compressor

A time-dependent linearized approach is used to predict the amplification or the decay of an initial perturbation in the multistage axial compressor of high hub-to-tip ratio. This analysis shows that for unstalled flow regimes the change in perturbation amplitude remains limited. The linearized theory remains valid until the stall limit. It is shown that, near this limit, peripheral propagation of an induced perturbation takes place at an angular velocity close to one-half of rotor angular velocity. However in most cases this perturbation has a limited amplitude.

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.

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