Investigating the effect of the impeller blade gradient angle on the compressor reliability

2021 ◽  
pp. 095440702110349
Author(s):  
Song Li ◽  
Xinle Yang ◽  
Weikang Li ◽  
Meiling Tang
Keyword(s):  
Natural Frequency ◽  
Pressure Ratio ◽  
Equivalent Stress ◽  
Frequency Multiplication ◽  
Impeller Blade ◽  
Inertia Moment ◽  
Blade Thickness ◽  
Cantilever Length ◽  
Compressor Impeller ◽  
Compressor Reliability

Studies show that operating stress and natural frequency of the turbocharger impeller are two key parameters that affect the service life of the turbocharger. In this regard, NREC and ANSYS software are utilized in the present study to design impellers and calculate the impeller stress, natural frequency, and the inertia moment of the impeller for each baseline impeller and their modifications. Furthermore, modal tests are carried out to verify the simulation results. Finally, the compressor characteristic maps before and after the blade gradient angle optimization are compared. Obtained results show that compared with the cantilever length, the blade thickness has a remarkable influence on the blade gradient angle. Moreover, it is found that the correlation between the blade gradient angle and the first-order frequency multiplication ratio is linear. As the blade gradient angle increases, the maximum stress at the blade root of the compressor initially decreases and then increases. The value of the blade gradient angle varies within the range of 2.288°–3.955°. Moreover, the closer the gradient angle to 3.26°, the smaller the maximum equivalent stress of the impeller, and the higher the impeller strength. The greater the thickness of the blade, the longer the cantilever length of the impeller, and the greater the inertia moment. Optimizing the blade gradient angle can improve the efficiency of the compressor without changing the pressure ratio and flow rate. It should be indicated that error between the results from the simulation and the experiment is within the range 1.736%–1.254%. Therefore, the calculation results are reliable. It is concluded that the regular pattern of the blade gradient angle affects the compressor impeller stress and its natural frequency. The present article is expected to provide a helpful theoretical basis for designing an optimized compressor impeller.

scholarly journals Aerodynamic and Structural Characteristics of a Centrifugal Compressor Impeller

2019 ◽  
Vol 9 (16) ◽  
pp. 3416 ◽  
Author(s):  
T R Jebieshia ◽  
Senthil Kumar Raman ◽  
Heuy Dong Kim
Keyword(s):  
Centrifugal Compressor ◽  
Structural Characteristics ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Von Mises Stress ◽  
Impeller Blade ◽  
Compressor Impeller ◽  
The One ◽  
Von Mises ◽  
Von Mises Stresses

The present study focuses on the aerodynamic performance and structural analysis of the centrifugal compressor impeller. The performance characteristics of the impeller are analyzed with and without splitter blades by varying the total number of main and splitter blades. The operating conditions of the compressor under centrifugal force and pressure load from the aerodynamic analysis are applied to the impeller blade and hub to perform the one-way Fluid–Structure Interaction (FSI). For the stress assessment, maximum equivalent von Mises stresses in the impeller blades are compared with the maximum allowable stress of the impeller material. The effects of varying the pressure field on the deformation and stress of the impeller are also calculated. The aerodynamic and structural performance of the centrifugal compressor at 73,000 rpm are investigated in terms of the efficiency, pressure ratio, equivalent von Mises stress, and total deformation of the impeller.

Detuning the Natural Frequencies of a Compressor Impeller Blade Through the Design Optimization

2015 ◽  
Author(s):  
Alexander O. Pugachev ◽  
Alexander V. Sheremetyev ◽  
Viktor V. Tykhomirov ◽  
Alexey V. Petrov
Keyword(s):  
Natural Frequency ◽  
Centrifugal Compressor ◽  
Natural Frequencies ◽  
Optimization Problems ◽  
Detailed Comparison ◽  
Element Model ◽  
Optimization Method ◽  
Design Parameters ◽  
Impeller Blade ◽  
Compressor Impeller

This paper describes a theoretical approach to shift individual natural frequencies of centrifugal compressor impeller blades. The approach applies sizing optimization of blade’s geometry using a gradient-based optimization method. Calculation of gradients is carried out by the finite-difference method. A new centrifugal compressor blade profile generator incorporating a blade parametrization procedure is developed. The blade’s geometry is parametrized using intuitive geometric parameters. Five design parameters related to the length of the sectional profile generator line, profile thicknesses and rotation angles at hub and shroud are defined for each of the blade sectional profiles. In addition, two global design parameters are defined to control rigid rotation of the blade hub and shroud sections in circumferential direction. Four nonlinear optimization problems containing multiple frequency constraints and constraints on the static equivalent stresses are considered. The optimization aims are either shifting a particular natural frequency of a blade or minimization of blade’s mass. For instance, one of the considered optimization problems is to decrease the 1st natural frequency of an impeller blade by 5%, while the 2nd and the 3rd natural frequencies must be simultaneously increased by 5%. The analysis is applied to the centrifugal compressor of a small-size turboprop engine. A three-dimensional finite element model of the impeller blade is developed in ANSYS Mechanical software package to perform static and modal analyses. The results of the optimization show that the code can meet defined objectives and constraints with reasonable accuracy. A detailed comparison of optimized profiles with the baseline geometry is provided.

scholarly journals Optimal Design of a Centrifugal Compressor Impeller Using Evolutionary Algorithms

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Soo-Yong Cho ◽  
Kook-Young Ahn ◽  
Young-Duk Lee ◽  
Young-Cheol Kim
Keyword(s):  
Centrifugal Compressor ◽  
Optimization Algorithm ◽  
Pressure Ratio ◽  
Optimization Technique ◽  
Computational Time ◽  
Impeller Blade ◽  
Design Variables ◽  
Compressor Impeller ◽  
Artificial Neural Network Ann ◽  
Geometric Variation

An optimization study was conducted on a centrifugal compressor. Eight design variables were chosen from the control points for the Bezier curves which widely influenced the geometric variation; four design variables were selected to optimize the flow passage between the hub and the shroud, and other four design variables were used to improve the performance of the impeller blade. As an optimization algorithm, an artificial neural network (ANN) was adopted. Initially, the design of experiments was applied to set up the initial data space of the ANN, which was improved during the optimization process using a genetic algorithm. If a result of the ANN reached a higher level, that result was re-calculated by computational fluid dynamics (CFD) and was applied to develop a new ANN. The prediction difference between the ANN and CFD was consequently less than 1% after the 6th generation. Using this optimization technique, the computational time for the optimization was greatly reduced and the accuracy of the optimization algorithm was increased. The efficiency was improved by 1.4% without losing the pressure ratio, and Pareto-optimal solutions of the efficiency versus the pressure ratio were obtained through the 21st generation.

Instantaneous Measurements in the Jet-Wake Discharge Flow of a Centrifugal Compressor Impeller

1975 ◽  
Vol 97 (3) ◽  
pp. 337-345 ◽  
Author(s):  
D. Eckardt
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Theoretical Models ◽  
Vaneless Diffuser ◽  
Impeller Blade ◽  
Measuring Systems ◽  
Compressor Design ◽  
Wake Patterns ◽  
Compressor Impeller ◽  
Critical Problems

One of the critical problems in centrifugal compressor design is the diffuser-impeller interaction. Up to now, theoretical models, which describe one of the salient features of this problem, the impeller discharge mixing process, appear to be proved experimentally only at low tip speeds. In the present study investigations on this subject were accomplished in the vaneless diffuser of a low-pressure ratio centrifugal compressor, running at tip speeds of 300 m/s. Detailed, instantaneous measurements in the impeller discharge mixing zone were performed by high-frequency measuring systems. Relative velocity distributions at the exit of impeller blade channels show pronounced jet/wake-patterns. The radial extension of flow distortions in the vaneless diffuser entry region, caused by rotating wakes, reached up to higher radius ratios than predicted by theoretical models.

scholarly journals Technical aspects of a large size industrial process turbo compressor revamp

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Piotr Świder ◽  
Zbigniew Kozanecki Jr ◽  
Marek Graczykowski ◽  
Władysław Kryłłowicz
Keyword(s):  
Power Consumption ◽  
Pressure Ratio ◽  
Industrial Process ◽  
Operating Parameters ◽  
General Outline ◽  
Impeller Blade ◽  
Technical Aspects ◽  
Large Size ◽  
Compressor Impeller ◽  
Turbo Compressor

AbstractThis paper describes several modernization aspects of the process 8 MW air compressor and its driver. The main aim of the revamp was to increase internal efficiencies of both the compressor and turbine and increase the load of the compressor without additional power consumption. The original pressure ratio was preserved. To meet these requirements a redesign of the flow path of both machineswas necessary.Moreover, the turbineworking conditions were changed from extraction-condensing to condensing. In terms of compressor, impeller blade redesign, adaptation of diffusers and Abradable seals were a part of the scope. The revamp was completed in April 2014 with all the requirements met. This paper covers the general outline and a comparison of the original and modernized machine operating parameters, design and technical assumptions and also describes some problematic issues which occurred during the realization of the project.

Performance Analysis of the Impeller of a Centrifugal Air Compressor

2019 ◽  
Author(s):  
T. R. Jebieshia ◽  
S. K. Raman ◽  
H. D. Kim
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Von Mises Stress ◽  
Structural Performance ◽  
Impeller Blade ◽  
Compressor Impeller ◽  
The One ◽  
Von Mises ◽  
Von Mises Stresses

Abstract The present study focuses on the aerodynamic performance and structural analysis of the centrifugal compressor impeller. Performance characteristics of the impeller are analyzed with and without splitter blades by varying the total number of main and splitter blades. The operating conditions of the compressor under centrifugal force and pressure load from the aerodynamic analysis were applied to the impeller blade and hub to perform the one-way Fluid-Structure Interaction (FSI). For the stress assessment, maximum equivalent von-Mises stresses in the impeller blades are compared with the maximum allowable stress of the impeller material. The effects of varying pressure field on the deformation and stress of the impeller is also calculated. The aerodynamic and structural performance of the centrifugal compressor at 73000 rpm are investigated in terms of the efficiency, pressure ratio, equivalent von-Mises stress, and total deformation of the impeller.

Effects of Disk Geometry on Strength of a Centrifugal Compressor Impeller for a High Pressure Ratio Turbocharger

2012 ◽  
Author(s):  
Xinqian Zheng ◽  
Lei Jin ◽  
Yangjun Zhang ◽  
Huihua Qian ◽  
Fenghu Liu
Keyword(s):  
High Pressure ◽  
Centrifugal Compressor ◽  
Internal Combustion Engines ◽  
Maximum Stress ◽  
Pressure Ratio ◽  
Equivalent Stress ◽  
Geometric Parameters ◽  
Element Analysis ◽  
High Pressure Ratio ◽  
Compressor Impeller

High pressure ratio turbocharger technology is widely used to lower fuel consumption, reduce emissions and improve power density of internal combustion engines. The centrifugal compressor is the key component of turbochargers. The reliability of compressor impeller becomes critical with increasing pressure ratio. For extending its maximum rotational speed limits, it is important to improve the impeller’s disk geometry to decease stress. In order to investigate the effects of disk geometric parameters on the strength of a centrifugal compressor impeller, a 3-D finite element analysis (FEA) with various disk geometric parameters was performed in this paper. Subsequently, the impeller’s disk geometry was improved to decrease the maximum stress. The results show that the maximum von Mises equivalent stress in the core of the disk of the improved impeller could be decreased by 19%. Further, the maximum stress of another improved impeller without shaft bore decreases by 50%. That means, the improved impeller can bear higher pressure ratios or use cheaper material with lower ultimate tensile strength.

scholarly journals A Proper Shape of the Trailing Edge Modification to Solve a Housing Damage Problem in a Gas Turbine Power Plant

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 705
Author(s):  
Thodsaphon Jansaengsuk ◽  
Mongkol Kaewbumrung ◽  
Wutthikrai Busayaporn ◽  
Jatuporn Thongsri
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Structural Dynamics ◽  
Pressure Ratio ◽  
Equivalent Stress ◽  
Total Deformation ◽  
Trailing Edge ◽  
Housing Damage ◽  
The Difference ◽  
Gas Turbine Power Plant

To solve the housing damage problem of a fractured compressor blade (CB) caused by an impact on the inner casing of a gas turbine in the seventh stage (from 15 stages), modifications of the trailing edge (TE) of the CB have been proposed, namely 6.5 mm curved cutting and a combination of 4 mm straight cutting with 6.5 mm curved cutting. The simulation results of the modifications in both aerodynamics variables Cl and Cd and the pressure ratio, including structural dynamics such as a normalized power spectrum, frequency, total deformation, equivalent stress, and the safety factor, found that 6.5 mm curved cutting could deliver the aerodynamics and structural dynamics similar to the original CB. This result also overcomes the previous work that proposed 5.0 mm straight cutting. This work also indicates that the operation of a CB gives uneven pressure and temperature, which get higher in the TE area. The slightly modified CB can present the difference in the properties of both the aerodynamics and the structural dynamics. Therefore, any modifications of the TE should be investigated for both properties simultaneously. Finally, the results from this work can be very useful information for the modification of the CB in the housing damage problem of the other rotating types of machinery in a gas turbine power plant.

Redesign of a Compressor Stage for a High-Performance Electric Supercharger in a Heavily Downsized Engine

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Peng Wang ◽  
Mehrdad Zangeneh ◽  
Bryn Richards ◽  
Kevin Gray ◽  
James Tran ◽  
...  
Keyword(s):  
Design Method ◽  
Pressure Ratio ◽  
Compressor Stage ◽  
Impeller Blade ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Margin ◽  
Stable Operating ◽  
Inverse Design Method ◽  
Ported Shroud

Engine downsizing is a modern solution for the reduction of CO2 emissions from internal combustion engines. This technology has been gaining increasing attention from industry. In order to enable a downsized engine to operate properly at low speed conditions, it is essential to have a compressor stage with very good surge margin. The ported shroud, also known as the casing treatment, is a conventional way used in turbochargers to widen the working range. However, the ported shroud works effectively only at pressure ratios higher than 3:1. At lower pressure ratio, its advantages for surge margin enhancements are very limited. The variable inlet guide vanes are also a solution to this problem. By adjusting the setting angles of variable inlet guide vanes, it is possible to shift the compressor map toward the smaller flow rates. However, this would also undermine the stage efficiency, require extra space for installing the inlet guide vanes, and add costs. The best solution is therefore to improve the design of impeller blade itself to attain high aerodynamic performances and wide operating ranges. This paper reports a recent study of using inverse design method for the redesign of a centrifugal compressor stage used in an electric supercharger, including the impeller blade and volute. The main requirements were to substantially increase the stable operating range of the compressor in order to meet the demands of the downsized engine. The three-dimensional (3D) inverse design method was used to optimize the impeller geometry and achieve higher efficiency and stable operating range. The predicted performance map shows great advantages when compared with the existing design. To validate the computational fluid dynamics (CFD) results, this new compressor stage has also been prototyped and tested. It will be shown that the CFD predictions have very good agreement with experiments and the redesigned compressor stage has improved the pressure ratio, aerodynamic efficiency, choke, and surge margins considerably.

Laser cleaning of sulfide scale on compressor impeller blade

2015 ◽  
Vol 355 ◽  
pp. 334-340 ◽  
Author(s):  
Q.H. Tang ◽  
D. Zhou ◽  
Y.L. Wang ◽  
G.F. Liu
Keyword(s):  
Laser Cleaning ◽  
Impeller Blade ◽  
Compressor Impeller
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