scholarly journals Experimental Investigation of Unsteady Pressure on an Axial Compressor Rotor Blade Surface

2010 ◽  
Vol 02 (02) ◽  
pp. 131-136 ◽  
Author(s):  
Qingwei Wang ◽  
Bo Liu ◽  
Xiaorong Xiang ◽  
Xiangfeng Bo ◽  
Weimin Hou
Keyword(s):  
Experimental Investigation ◽  
Rotor Blade ◽  
Axial Compressor ◽  
Blade Surface ◽  
Unsteady Pressure ◽  
Compressor Rotor

Cold Blade Profile Generation Methodology for Compressor Rotor Blades Using FSI Approach

2017 ◽  
Author(s):  
Kirubakaran Purushothaman ◽  
Sankar Kumar Jeyaraman ◽  
Ajay Pratap ◽  
Kishore Prasad Deshkulkarni
Keyword(s):  
Aspect Ratio ◽  
Rotor Blade ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Blade Profile ◽  
Interaction Technique ◽  
Compressor Rotor ◽  
Blade Shape ◽  
Blade Geometry

This paper describes a methodology for obtaining correct blade geometry of high aspect ratio axial compressor blades during running condition taking into account of blade untwist and bending. It discusses the detailed approach for generating cold blade geometry for axial compressor rotor blades from the design blade geometry using fluid structure interaction technique. Cold blade geometry represents the rotor blade shape at rest, which under running condition deflects and takes a new operating blade shape under centrifugal and aerodynamic loads. Aerodynamic performance of compressor primarily depends on this operating rotor blade shape. At design point it is expected to have the operating blade shape same as the intended design blade geometry and a slight mismatch will result in severe performance deterioration. Starting from design blade profile, an appropriate cold blade profile is generated by applying proper lean and pre-twist calculated using this methodology. Further improvements were carried out to arrive at the cold blade profile to match the stagger of design profile at design operating conditions with lower deflection and stress for first stage rotor blade. In rear stages, thermal effects will contribute more towards blade deflection values. But due to short blade span, deflection and untwist values will be of lower values. Hence difference between cold blade and design blade profile would be small. This methodology can especially be used for front stage compressor rotor blades for which aspect ratio is higher and deflections are large.

Effect of Rotor Tip Gap Variation at the Rear Stages of an Axial Flow Compressor

2012 ◽  
Vol 225 ◽  
pp. 233-238
Author(s):  
A.M. Pradeep ◽  
R.N. Chiranthan ◽  
Debarshi Dutta ◽  
Bhaskar Roy
Keyword(s):  
Rotor Blade ◽  
Cross Flow ◽  
Axial Compressor ◽  
Axial Flow ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Suction Surface ◽  
Design Point ◽  
Compressor Rotor ◽  
Multi Stage

In this paper, detailed analysis of the tip flow of an axial compressor rotor blade has been carried out using the commercial CFD package ANSYS CFX. The rotor blade was designed such that it is reminiscent of the rear stages of a multi-stage axial compressor. The effects of varying tip gaps are studied using CFD simulations for overall pressure rise and flow physics of the tip flow at the design point and near the peak pressure point. Rig tests of a low speed research compressor rotor with 3% tip clearance provided characteristics plots for validation of the CFD results. With increase in clearance from 1% to 4%, the rotor pressure rise at the design point was observed to decrease linearly. Increase in the clearance increases the cross flow across the tip; however, the magnitude of the average jet velocity crossing the tip decreases. The tip leakage vortex was observed to stay close to the suction surface with increase in clearance.

scholarly journals Development of Small Rotating Stall in a Single Stage Axial Compressor

1985 ◽  
Author(s):  
K. Mathioudakis ◽  
F. A. E. Breugelmans
Keyword(s):  
Experimental Study ◽  
Rotor Blade ◽  
Axial Compressor ◽  
Propagation Speed ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Blade Surface ◽  
Hot Wire ◽  
Additional Information ◽  
Cell Pattern

In this paper we present the results of a detailed experimental study of the development of small rotating stall, as it appears in a one stage axial compressor. Stationary hot-wire probes are used to measure the variation of amplitude and propagation speed of the disturbances caused by small stall. Measurements near the rotor blade surface with rotating probes provide additional information on the nature of the phenomenon. The development of the cell pattern for different operating conditions is studied. The different character from what is known as “big stall” is demonstrated.

scholarly journals The Effect of Adding Roughness and Thickness to a Transonic Axial Compressor Rotor

1995 ◽  
Vol 117 (4) ◽  
pp. 491-505 ◽  
Author(s):  
K. L. Suder ◽  
R. V. Chima ◽  
A. J. Strazisar ◽  
W. B. Roberts
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Axial Compressor ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Blade Surface ◽  
Suction Surface ◽  
Compressor Rotor ◽  
Performance Deterioration ◽  
Design Speed

The performance deterioration of a high-speed axial compressor rotor due to surface roughness and airfoil thickness variations is reported. A 0.025 mm (0.001 in.) thick rough coating with a surface finish of 2.54–3.18 rms μm (100–125 rms μin.) is applied to the pressure and suction surface of the rotor blades. Coating both surfaces increases the leading edge thickness by 10 percent at the hub and 20 percent at the tip. Application of this coating results in a loss in efficiency of 6 points and a 9 percent reduction in the pressure ratio across the rotor at an operating condition near the design point. To separate the effects of thickness and roughness, a smooth coating of equal thickness is also applied to the blade. The smooth coating surface finish is 0.254–0.508 rms μm (10–20 rms μin.), compared to the bare metal blade surface finish of 0.508 rms pm (20 rms μin.). The smooth coating results in approximately half of the performance deterioration found from the rough coating. Both coatings are then applied to different portions of the blade surface to determine which portions of the airfoil are most sensitive to thickness/roughness variations. Aerodynamic performance measurements are presented for a number of coating configurations at 60, 80, and 100 percent of design speed. The results indicate that thickness/roughness over the first 2 percent of blade chord accounts for virtually all of the observed performance degradation for the smooth coating, compared to about 70 percent of the observed performance degradation for the rough coating. The performance deterioration is investigated in more detail at design speed using laser anemometer measurements as well as predictions generated by a quasi-three-dimensional Navier–Stokes flow solver, which includes a surface roughness model. Measurements and analysis are performed on the baseline blade and the full-coverage smooth and rough coatings. The results indicate that adding roughness at the blade leading edge causes a thickening of the blade boundary layers. The interaction between the rotor passage shock and the thickened suction surface boundary layer then results in an increase in blockage, which reduces the diffusion level in the rear half of the blade passage, thus reducing the aerodynamic performance of the rotor.

Numerical Studies on the Effect of Gurney Flap on Aerodynamic Performance and Stall Margin of a Transonic Axial Compressor Rotor

2014 ◽  
Author(s):  
Mudassir Ahmed M. Rafeeq ◽  
Quamber H. Nagpurwala ◽  
Subbaramu Shivaramaiah
Keyword(s):  
Total Pressure ◽  
Rotor Blade ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Stall Margin ◽  
Compressor Rotor ◽  
Numerical Studies ◽  
Gurney Flap ◽  
Total Pressure Ratio

Numerical studies have been carried out on the effectiveness of trailing edge Gurney flap on a transonic axial compressor rotor. The baseline geometry of the rotor blade was modified at the trailing edge by introducing Gurney flaps of varying depth and span-wise length, viz. 1 mm, 2 mm and 3 mm depth with 20% span length of Gurney flap from tip (designated as GF1-20, GF2-20 and GF3-20 respectively), and 1 mm depth with 50% and 100% span length (designated as GF1-50 and GF1-100 respectively). Geometric models of the compressor rotor without and with Gurney flaps were generated using CATIA V5 software and CFD simulations at 100% design rotor speed were carried out using ANSYS CFX software. Results have shown that the compressor total pressure ratio increased with increase in both depth and spanwise length of Gurney flap. Peak pressure ratio increased from 1.51 for baseline case to 1.58 for rotor GF1-100. However, the peak isentropic efficiency remained almost constant for various Gurney flap configurations, except for GF1-100 which showed a tendency for improvement in efficiency. The stall margin reduced with the introduction of Gurney flap and was lowest for configuration GF1-100 which gave highest peak pressure ratio. Higher blade loading with Gurney flap was responsible for lowering the stall margin. Analysis of the flow through the blade passages has shown clear formation of trailing end vortex structure in the presence of Gurney flap that resulted in bending of the streamlines towards suction surface of the rotor blade, with consequent reduction in flow deviation and increased flow deflection, and hence increased total pressure ratio.

Effect of Inflow Circumferential Distortion on a Transonic Axial Compressor

2017 ◽  
Author(s):  
Yuyun Li ◽  
Zhiheng Wang ◽  
Guang Xi
Keyword(s):  
Total Pressure ◽  
Rotor Blade ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Leading Edge ◽  
Inlet Distortion ◽  
Compressor Rotor ◽  
Structure Changes ◽  
Transonic Axial Compressor

The Inlet distortion, which may lead to the stability reduction or structure failure, is often non-ignorable in an axial compressor. In the paper, the three-dimensional unsteady numerical simulations on the flow in NASA rotor 67 are carried out to investigate the effect of inlet distortion on the performance and flow structure in a transonic axial compressor rotor. A sinusoidal circumferential total pressure distortion with eleven periods per revolution is adopted to study the interaction between the transonic rotor and inlet circumferential distortion. Concerning the computational expense, the flow in two rotor blade passages is calculated. Various intensities of the total pressure distortion are discussed, and the detailed flow structures under different rotating speeds near the peak efficiency condition are analyzed. It is found that the distortion has a positive effect on the flow near the hub. Even though there is no apparent decrease in the rotor efficiency or total pressure ratio, an obvious periodic loading exists over the whole blade. The blade loadings are concentrated in the region near the leading edge of the rotor blade or regions affected by the oscillating shocks near the pressure side. The time averaged location of shock structure changes little with the distortion, and the motion of shocks and the interactions between the shock and the boundary layer make a great contribution to the instability of the blade structure.

Calculation of natural frequencies and effective elastic properties of the axial compressor rotor blade

2016 ◽  
Vol 11 (1) ◽  
pp. 81-87
Author(s):  
A.A. Filippov
Keyword(s):  
Composite Structures ◽  
Rotor Blade ◽  
Natural Frequencies ◽  
Axial Compressor ◽  
Homogenization Method ◽  
Asymptotic Homogenization ◽  
Turbine Engine ◽  
Composite Blade ◽  
Compressor Rotor ◽  
Asymptotic Homogenization Method

The results of the numerical calculations of the natural frequencies of the composite rotor blade axial compressor of aircraft gas turbine engine. Shows the way of solving of а unit cell problem arising in the application of asymptotic homogenization method to elastic deformation of regular composite structures. Components of the effective stiffness matrix of the composite blade obtained by asymptotic homogenization.

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