scholarly journals A Novel Surface Parametric Method and Its Application to Aerodynamic Design Optimization of Axial Compressors

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1230
Author(s):  
Zhaohui Dong ◽  
Jinxin Cheng ◽  
Tian Liu ◽  
Gaolu Si ◽  
Buchuan Ma
Keyword(s):  
Control Method ◽  
Parametric Method ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Blade Surface ◽  
Aerodynamic Optimization ◽  
Suction Surface ◽  
Parametric Control ◽  
Surge Margin ◽  
Design Speed

A novel parametric control method for the compressor blade, the full-blade surface parametric method, is proposed in this paper. Compared with the traditional parametric method, the method has good surface smoothness and construction convenience while maintaining low-dimensional characteristics, and compared with the semi-blade surface parametric method, the proposed method has a larger degree of geometric deformation freedom and can account for changes in both the suction surface and pressure surface. Compared with the semi-blade surface parametric method, the method only has four more control parameters for each blade, so it does not significantly increase the optimization time. The effectiveness of this novel parametric control method has been verified in the aerodynamic optimization field of compressors by an optimization case of Stage35 (a single-stage transonic axial compressor) under multi-operating conditions. The optimization case has brought the following results: the adiabatic efficiency of the optimized blade at design speed is 1.4% higher than that of the original one and the surge margin 2.9% higher, while at off-design speed, the adiabatic efficiency is improved by 0.6% and the surge margin by 1.3%.

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.

scholarly journals Research on Aerodynamic Optimization Method of Multistage Axial Compressor under Multiple Working Conditions Based on Phased Parameterization Strategy

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Jinxin Cheng ◽  
Zhaohui Dong ◽  
Shengfeng Zhao ◽  
Hang Xiang
Keyword(s):  
Working Conditions ◽  
Axial Compressor ◽  
Optimization Method ◽  
Optimization Process ◽  
Second Phase ◽  
Aerodynamic Optimization ◽  
Surge Margin ◽  
Modification Method ◽  
Design Speed ◽  
Multistage Axial Compressor

Multistage axial compressor is the key component of aeroengine and gas turbine to realize energy conversion. In order to avoid the “curse of dimensionality” problem in the global optimization process of AL-31F four-stage low-pressure compressor under multiple working conditions, an optimization method based on phased parameterization strategy is proposed. The method uses the idea of “exploration before exploitation” for reference and divides the optimization process into two phases. In the first phase, the traditional parametric modification method based on stacking line is adopted; in the second phase, the full-blade surface parametric modification method with significant low-dimensional characteristics is adopted. Based on the improved artificial bee colony algorithm, a multitask concurrent optimization system is built on the supercomputing platform, and the engineering optimization solution is obtained within 91 hours. The optimization results are as follows: under the condition of meeting the constraints, the adiabatic efficiency is increased by 0.3% and the surge margin is 4.0% at the design speed; the adiabatic efficiency is increased by 0.8% and the surge margin is 2.3% at the off-design speed. These results verify the usefulness and reliability of the optimization method in the field of aerodynamic optimization of a multistage axial flow compressor.

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

1994 ◽  
Author(s):  
Kenneth L. Suder ◽  
Rodrick V. Chima ◽  
Anthony J. Strazisar ◽  
William B. Roberts
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Performance Degradation ◽  
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 microinches) is applied to the pressure and suction surface of the rotor blades. Coating both surfaces increases the leading edge thickness by 10% at the hub and 20% at the tip. Application of this coating results in a loss in efficiency of 6 points and a 9% 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 microinches), compared to the bare metal blade surface finish of 0.508 RMS μm (20 RMS microinches). 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% of design speed. The results indicate that thickness/roughness over the first 10% of blade chord accounts for virtually all of the observed performance degradation for the smooth coating, compared to about 70% 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-3D 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 coating the blade 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.

Aerodynamic Instability and Life Limiting Effects of Inlet and Interstage Water Injection Into Gas Turbines

2005 ◽  
Author(s):  
Klaus Brun ◽  
Rainer Kurz ◽  
Harold R. Simmons
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Water Injection ◽  
Axial Compressor ◽  
Careful Analysis ◽  
Operating Conditions ◽  
Aerodynamic Stability ◽  
Surge Margin ◽  
Power Enhancement ◽  
Aerodynamic Instability

Gas turbine power enhancement technologies such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection are being employed by end-users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Particularly, the effect of these add-on devices, off-design operating conditions, non-standard fuels, and compressor degradation/fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. Nonetheless, compressor aerodynamic instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure; i.e., a careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses non-standard fuels. This paper discusses a simplified method to evaluate the principal factors that affect the aerodynamic stability of a single shaft gas turbine’s axial compressor. As an example, the method is applied to a frame type gas turbine and results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities but that it can be a contributing factor if for other reasons the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.

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 Experimental Evaluation of the Effectiveness of Online Water-Washing in Gas Turbine Compressors

2014 ◽  
Author(s):  
Klaus Brun ◽  
William C. Foiles ◽  
Terrence A. Grimley ◽  
Rainer Kurz
Keyword(s):  
Wind Tunnel ◽  
Gas Turbine ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Blade Surface ◽  
Compressor Blades ◽  
Flow Recirculation ◽  
Water Washing ◽  
Air Stream ◽  
Recirculation Zones

An investigation of the effectiveness of online combustion turbine axial compressor washing using various purity grade waters and commercial washing detergents was performed. For this project, blade surface fouling dirt was obtained from gas turbine axial compressor blades installed at various field sites. The dirt was analyzed to determine the composition and consistency of typical blade surface fouling materials. A representative dirt formula and blade coating procedure was developed so that comparative tests could be performed using various cleaning fluids. Dirt coated blades were installed in a wind tunnel capable of simulating compressor operating conditions. A spray nozzle upstream of the blade test section was used for washing blades with five different test liquids to determine the effectiveness or advantages of any liquid. Once this testing was completed, a similar test setup was then utilized to inject a mixture of formulated fouling dirt and the various online cleaning liquids upstream of the blade into the wind tunnel to assess redeposit characteristics. The effect of high-purity water versus regular water on fouling dirt was also studied in separate residue experiments. Results indicate that spraying cleaning fluid into a flowing air stream is a viable means of cleaning a compressor blade. Each of the fluids was able to clean the test blade at both low and high air velocities and at different blade incident angles. Within the parameters/fluids tested, the results indicate that: 1. The blade cleaning is primarily a mechanical function and does not depend on the type of fluid used for cleaning. The results showed that most of the cleaning occurs shortly after the cleaning fluid is introduced into the flow stream. 2. Dirt removed from the blades may redeposit in other areas as the cleaning fluid is evaporated. Redeposit occurred in flow recirculation zones during the cleaning tests, and heated flow tests demonstrated dirt deposit in the presence of a cleaning fluid. In addition, the type of fluid used for cleaning has no effect on the redeposit characteristics of the dirt. 3. Blade erosion was not found to be a significant issue for the short durations that online water-washing was performed. However, uncontrolled water-washing (or overspray) for extended periods of time did result in measureable leading and trailing edge blade erosions.

scholarly journals Experimental and Computational Investigation of the Tip Clearance Flow in a Transonic Axial Compressor Rotor

1996 ◽  
Vol 118 (2) ◽  
pp. 218-229 ◽  
Author(s):  
K. L. Suder ◽  
M. L. Celestina
Keyword(s):  
Axial Compressor ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Vortex Interaction ◽  
Peak Efficiency ◽  
Tip Clearance Flow ◽  
Compressor Rotor ◽  
Clearance Flow ◽  
Transonic Axial Compressor ◽  
Design Speed

Experimental and computational techniques are used to investigate tip clearance flows in a transonic axial compressor rotor at design and part-speed conditions. Laser anemometer data acquired in the endwall region are presented for operating conditions near peak efficiency and near stall at 100 percent design speed and at near peak efficiency at 60 percent design speed. The role of the passage shock/leakage vortex interaction in generating endwall blockage is discussed. As a result of the shock/vortex interaction at design speed, the radial influence of the tip clearance flow extends to 20 times the physical tip clearance height. At part speed, in the absence of the shock, the radial extent is only five times the tip clearance height. Both measurements and analysis indicate that under part-speed operating conditions a second vortex, which does not originate from the tip leakage flow, forms in the end-wall region within the blade passage and exits the passage near midpitch. Mixing of the leakage vortex with the primary flow downstream of the rotor at both design and part-speed conditions is also discussed.

Shape Optimization of Axial Compressor Blades Using Adjoint Method With Emphasis on Thickness Distribution

2015 ◽  
Author(s):  
Jia Yu ◽  
Lucheng Ji ◽  
Weiwei Li ◽  
Weilin Yi
Keyword(s):  
Optimization Design ◽  
Adjoint Method ◽  
Thickness Distribution ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Aerodynamic Optimization ◽  
Suction Surface ◽  
Compressor Blades ◽  
Blade Thickness ◽  
Shape Parameterization

Shape parameterization plays an important role in aerodynamic optimization design of axial compressor blades. Blade thickness is one of the most important parameters in blade design, which has strong influence on compressor aerodynamic performance. However, the previous adjoint-based optimization designs using the Hicks-Henne functions only parameterized the perturbations to the tangential coordinates of points on suction surface or meanline, and kept the tangential thickness of the blade constant during the optimization process. In previous development work of turbomachinery blade optimization using adjoint method and thin shear-layer N-S equations, a new shape parameterization is introduced, which uses Hicks-Henne functions to parameterize the perturbations to both the tangential coordinates of mesh points on suction blade surface and the tangential thickness of the blade. This new approach is applied to the redesign of NASA rotor 67 and the results obtained with and without the blade tangential thickness parameterization are discussed in detail. The results show the redesign with and without the blade tangential thickness parameterization can both improve the aerodynamic performance of the axial compressor. However, the redesign with the blade tangential thickness parameterization can produce a consistently better performance than that without it.

scholarly journals Experimental Evaluation of the Effectiveness of Online Water-Washing in Gas Turbine Compressors

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Klaus Brun ◽  
Terrence A. Grimley ◽  
William C. Foiles ◽  
Rainer Kurz
Keyword(s):  
Wind Tunnel ◽  
Gas Turbine ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Blade Surface ◽  
Compressor Blades ◽  
Flow Recirculation ◽  
Water Washing ◽  
Air Stream ◽  
Recirculation Zones

An investigation of the effectiveness of online combustion turbine axial compressor washing using various purity grade waters and commercial washing detergents was performed. For this project, blade surface fouling dirt was obtained from gas turbine axial compressor blades installed at various field sites. The dirt was analyzed to determine consistency of typical blade surface fouling materials. A representative dirt formula and blade coating procedure was developed so that comparative tests could be performed using various cleaning fluids. Dirt coated blades were installed in a wind tunnel capable of simulating compressor operating conditions. A spray nozzle upstream of the blade test section was used for washing blades with five different test liquids to determine the effectiveness or advantages of any liquid. Once this testing was completed, a similar test setup was then utilized to inject a mixture of formulated fouling dirt and the various online cleaning liquids upstream of the blade into the wind tunnel to assess redeposit characteristics. The effect of high-purity water versus regular water on fouling dirt was also studied in separate residue experiments. Results indicate that spraying cleaning fluid into a flowing air stream is a viable means of cleaning a compressor blade. Each of the fluids was able to clean the test blade at both low and high air velocities and at different blade incident angles. Within the parameters/fluids tested, the results indicate that: (1) The blade cleaning is primarily a mechanical function and does not depend on the type of fluid used for cleaning. The results showed that most of the cleaning occurs shortly after the cleaning fluid is introduced into the flow stream. (2) Dirt removed from the blades may redeposit in other areas as the cleaning fluid is evaporated. Redeposit occurred in flow recirculation zones during the cleaning tests, and heated flow tests demonstrated dirt deposit in the presence of a cleaning fluid. In addition, the type of fluid used for cleaning has no effect on the redeposit characteristics of the dirt. (3) Blade erosion was not found to be a significant issue for the short durations that online water-washing was performed. However, uncontrolled water-washing (or overspray) for extended periods of time did result in measureable leading and trailing edge blade erosions.

A Blade Resonance Prediction Using Fluid-Structure Interaction Calculation Method and Comparison With the Test

2009 ◽  
Author(s):  
Daisuke Kariya ◽  
Toshiyuki Yamamoto ◽  
Kunihiko Ishihara
Keyword(s):  
Surface Pressure ◽  
Fluid Structure Interaction ◽  
Operating Conditions ◽  
Blade Surface ◽  
Axial Fan ◽  
Fluid Structure ◽  
Low Speed ◽  
Structure Interaction ◽  
Surface Pressure Distribution ◽  
Design Speed

In this study, nozzle-wake resonance of a low-speed axial fan blade is numerically analyzed, and compared with the test. The numerical method is fluid-structure interaction (FSI) calculation, which combines unsteady structural FEM and unsteady CFD. Instantaneous blade surface pressure distribution is calculated by CFD, which is used as a boundary condition of unsteady FEM. Blade response is then calculated by FEM, and the deformation of the blade is transferred to CFD. Advantage of this method is that it can include the effects of real geometry, blade/vane arrangement, operating conditions, etc. Aerodynamic damping is also included. In this study commercial codes are used for both CFD and FEM. On the other hand, the authors have built a test rig of low-speed two-stage axial fan, specially designed for this study. The second stage rotor (2R hereafter) blades are intentionally designed to have a resonance of 1st bending mode near design speed. Vibratory stress, amplitude, and unsteady surface pressure of 2R blades were measured. Comparison of measurement and calculation revealed the potential of FSI method. Though there were some discrepancies between prediction and measurement, the blade response was reasonably explained by lift fluctuation estimated from blade surface pressure.

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