Aerodynamic Retrofit Design for a High Pressure Compressor Using a High Hub/Tip Ratio Mixed-Flow Compressor

2020 ◽  
Author(s):  
Hang Xiang ◽  
Jiang Chen ◽  
Jinxin Cheng ◽  
Han Niu ◽  
Yi Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Load Capacity ◽  
Axial Compressor ◽  
Design Flow ◽  
Maximum Efficiency ◽  
Mixed Flow ◽  
High Pressure Compressor ◽  
Flow Compressor ◽  
Retrofit Design ◽  
Pressure Compressor

Abstract A high-load mixed-flow compressor with an extremely high inlet hub/tip ratio (0.889) is designed and analyzed for replacing the rear stages of a multistage high pressure axial compressor. The effects of blade number, splitter blades and dimensionless geometric parameters on the impeller performance are investigated by an improved loss model. A full-surface parameterization control method is adopted for blade optimizations of the mixed-flow impeller and the tandem stator. As a retrofit design of the multistage axial compressor, an unconventional type of axial-co-mixed-flow combined compressor scheme is proposed and discussed. Further, in order to minimize the axial dimension and maximize the load, this paper also proposed preliminary designs of the twin-stage mixed-flow compressor and the twin-stage counter-rotating mixed-flow compressor respectively equipped with the high hub/tip ratio mixed-flow compressor. The results indicate that the mixed-flow impeller configuration with 42 principal blades and splitter blades with a fifth of principal blade length has the maximum efficiency at design flow rate. Blade height/pitch ratio is a considerable parameter which demonstrates the interaction among hub/tip ratio, aspect ratio and solidity especially for high hub/tip ratio cascade designs. The mixed-flow compressor can greatly improve the load capacity of the high pressure compressor with slight impact on efficiency and surge margin. At low rotate speed, the mixed-flow impeller can maintain relatively high efficiency level and even carry a higher proportion of the load, while the tandem stator limits the overall efficiency improvement. Besides, structures with no return channel of the three unconventional combined compressors are beneficial to the reduction of dimension and cost, which shows the potential application prospects of high hub/tip ratio mixed-flow compressors.

Numerical Simulation of Particulates in Multistage Axial Compressors

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Swati Saxena ◽  
Giridhar Jothiprasad ◽  
Corey Bourassa ◽  
Byron Pritchard
Keyword(s):  
High Pressure ◽  
Axial Compressor ◽  
Airborne Particulate Matter ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Qualitative Comparison ◽  
Axial Compressors ◽  
Sand Erosion ◽  
High Pressure Compressor ◽  
Pressure Compressor

Aircraft engines ingest airborne particulate matter, such as sand, dirt, and volcanic ash, into their core. The ingested particulate is transported by the secondary flow circuits via compressor bleeds to the high pressure turbine and may deposit resulting in turbine fouling and loss of cooling effectiveness. Prior publications focused on particulate deposition and sand erosion patterns in a single stage of a compressor or turbine. This work addresses the migration of ingested particulate through the high pressure compressor (HPC) and bleed systems. This paper describes a 3D CFD methodology for tracking particles along a multistage axial compressor and presents particulate ingestion analysis for a high pressure compressor section. The commercial CFD multiphase solver ANSYS CFX® has been used for flow and particulate simulations. Particle diameters of 20, 40, and 60 μm are analyzed. Particle trajectories and radial particulate profiles are compared for these particle diameters. The analysis demonstrates how the compressor centrifuges the particles radially toward the compressor case as they travel through the compressor; the larger diameter particles being more significantly affected. Nonspherical particles experience more drag as compared to spherical particles, and hence a qualitative comparison between spherical and nonspherical particles is shown.

Impact of Manufacturing Variability on Multistage High-Pressure Compressor Performance

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Alexander Lange ◽  
Matthias Voigt ◽  
Konrad Vogeler ◽  
Henner Schrapp ◽  
Erik Johann ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Rise ◽  
Leading Edge ◽  
Back Pressure ◽  
Operating Conditions ◽  
Geometric Parameters ◽  
Maximum Efficiency ◽  
Novel Approach ◽  
High Pressure Compressor ◽  
Pressure Compressor

The present paper introduces a novel approach for considering manufacturing variability in the numerical simulation of a multistage high-pressure compressor (HPC). The manufacturing process is investigated by analyzing three of a total of ten rotor rows. Therefore, 150 blades of each of the three rows were 3D scanned to obtain surface meshes of real blades. The deviation of a scanned blade to the design intent is quantified by a vector of 14 geometric parameters. Interpolating the statistical properties of these parameters provides the manufacturing scatter for all ten rotor rows expressed by 140 probability density functions. The probabilistic simulation utilizes the parametric scatter information for generating 200 virtual compressors. The CFD analysis provides the performance of these compressors by calculating speed lines. Postprocessing methods are applied to statistically analyze the obtained results. It was found that the global performance parameters show a significantly wider scatter range for higher back pressure levels. The correlation coefficient and the coefficient of importance are utilized to identify the sensitivity of the results to the geometric parameters. It turned out that the sensitivities strongly shift for different operating points. While the leading edge geometry of all rotor rows dominantly influences the overall performance at maximum efficiency, the camber line parameters of the front stages become more important for higher back pressure levels. The analysis of the individual stage performance confirms the determining importance of the front stages—especially for highly throttled operating conditions. This leads to conclusions regarding the robustness of the overall HPC, which is principally determined by the efficiency and pressure rise of the front stages.

Design Work of a Compressor Stage Through High-To-Low Speed Compressor Transformation

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Zhang Chenkai ◽  
Hu Jun ◽  
Wang Zhiqiang ◽  
Gao Xiang
Keyword(s):  
High Pressure ◽  
Axial Compressor ◽  
Design Procedure ◽  
Parameter Design ◽  
Design Work ◽  
Global Parameter ◽  
Low Speed ◽  
High Pressure Compressor ◽  
Pressure Compressor ◽  
Modeling Principles

Low-speed model testing has advantages such as great accuracy and low cost and risk, so it is widely used in the design procedure of the high pressure compressor (HPC) exit stage. The low-speed model testing project is conducted in Nanjing University of Aeronautics and Astronautics (NUAA) to represent aerodynamic load and flow field structure of the seventh stage of a high-performance ten-stage high-pressure compressor. This paper outlines the design work of the low speed four-stage axial compressor, the third stage of which is the testing stage. The first two stages and the last stage provide the compressor with entrance and exit conditions, respectively. The high-to-low speed transformation process involves both geometric and aerodynamic considerations. Accurate similarities demand the same Mach number and Reynolds number, which will not be maintained due to motor power/size and its low-speed feature. Compromises of constraints are obvious. Modeling principles are presented in high-to-low speed transformation. Design work was carried out based on these principles. Four main procedures were conducted successively in the general design, including establishment of low-speed modeling target, global parameter design of modeling stage, throughflow aerodynamic design, and blading design. In global parameter design procedure, rotational speed, shroud diameter, hub-tip ratio, midspan chord, and axial spacing between stages were determined by geometrical modeling principles. During the throughflow design process, radial distributions of aerodynamic parameters such as D-factor, pressure-rise coefficient, loss coefficients, stage reaction, and other parameters were obtained by determined aerodynamic modeling principles. Finally, rotor and stator blade profiles of the low speed research compressor (LSRC) at seven span locations were adjusted to make sure that blade surface pressure coefficients agree well with that of the HPC. Three-dimensional flow calculations were performed on the low-speed four-stage axial compressor, and the resultant flow field structures agree well with that of the HPC. It is worth noting that a large separation zone appears in both suction surfaces of LSRC and HPC. How to diminish it through 3D blading design in the LSRC test rig is our further work.

Numerical Simulation of Particulates in Multi-Stage Axial Compressors

2016 ◽  
Author(s):  
Swati Saxena ◽  
Giridhar Jothiprasad ◽  
Corey Bourassa ◽  
Byron Pritchard
Keyword(s):  
High Pressure ◽  
Axial Compressor ◽  
Airborne Particulate Matter ◽  
Spherical Particles ◽  
Qualitative Comparison ◽  
Multi Stage ◽  
Sand Erosion ◽  
High Pressure Compressor ◽  
Multi Phase ◽  
Pressure Compressor

Aircraft engines ingest airborne particulate matter, such as sand, dirt, and volcanic ash, into their core. The ingested particulate is transported by the secondary flow circuits via compressor bleeds to the high pressure turbine and may deposit resulting in turbine fouling and loss of cooling effectiveness. Prior publications focused on particulate deposition and sand erosion patterns in a single stage of a compressor or turbine. The current work addresses the migration of ingested particulate through the high pressure compressor and bleed systems. This paper describes a 3D CFD methodology for tracking particles along a multi-stage axial compressor and presents particulate ingestion analysis for a high pressure compressor section. The commercial CFD multi-phase solver ANSYS CFX R has been used for flow and particulate simulations. Particle diameters of 20, 40, and 60 microns are analyzed. Particle trajectories and radial particulate profiles are compared for these particle diameters. The analysis demonstrates how the compressor centrifuges the particles radially towards the compressor case as they travel through the compressor; the larger diameter particles being more significantly affected. Non-spherical particles experience more drag as compared to spherical particles and hence a qualitative comparison between spherical and non-spherical particles is shown.

scholarly journals The comparative analysis of the selected construction types of axial compressor stage including the modal analysis

2017 ◽  
Vol 4 (17) ◽  
pp. 91-97
Author(s):  
Adam KOZAKIEWICZ ◽  
Olga GRZEJSZCZAK ◽  
Tomasz LACKI
Keyword(s):  
High Pressure ◽  
Comparative Analysis ◽  
Vibration Frequency ◽  
Vibration Spectrum ◽  
Axial Compressor ◽  
Point Of View ◽  
Compressor Stage ◽  
Jet Engine ◽  
High Pressure Compressor ◽  
Pressure Compressor

The article concerns the issues of the scope of optimization of the gas turbine jet engine. These issues include limiting the weight and number of engine parts. One way to reduce the weight and number of components, including the compressor assembly, is to use the BLISK's replacement construction. The replacement construction should meet the strength requirement and the vibration spectrum as well. The paper presents a comparative analysis of the influence of rotational speed on the characters and the vibration frequency of the single rotor stage of the high pressure compressor. The analysis was carried out for two different design solutions of the blade-disk connection: the classical and integral. The comparative analysis focused on three important from the point of view of operation, the engine operating ranges: work on the ground (idle) and work during take-off and climb the aircraft.

Impact of Manufacturing Variability on Multi–Stage High–Pressure Compressor Performance

2012 ◽  
Author(s):  
Alexander Lange ◽  
Matthias Voigt ◽  
Konrad Vogeler ◽  
Henner Schrapp ◽  
Erik Johann ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Rise ◽  
Leading Edge ◽  
Back Pressure ◽  
Operating Conditions ◽  
Geometric Parameters ◽  
Maximum Efficiency ◽  
Multi Stage ◽  
High Pressure Compressor ◽  
Pressure Compressor

The present paper introduces a novel approach for considering manufacturing variability in the numerical simulation of a multi–stage high–pressure compressor (HPC). The manufacturing process is investigated by analyzing three of totally ten rotor rows. Therefore, 150 blades of each of the three rows were 3D scanned to obtain surface meshes of real blades. The deviation of a scanned blade to the design intent is quantified by a vector of 14 geometric parameters. Interpolating the statistical properties of these parameters provides the manufacturing scatter for all ten rotor rows expressed by 140 probability density functions. The probabilistic simulation utilizes the parametric scatter information for generating 200 virtual compressors. The CFD analysis provides the performance of these compressors by calculating speed lines. Post–processing methods are applied to statistically analyze the obtained results. It was found that the global performance parameters show a significantly wider scatter range for higher back pressure levels. The correlation coefficient and the coefficient of importance are utilized to identify the sensitivity of the results to the geometric parameters. It turned out that the sensitivities strongly shift for different operating points. While the leading edge geometry of all rotor rows dominantly influences the overall performance at maximum efficiency, the camber line parameters of the front stages become more important for higher back pressure levels. The analysis of the individual stage performance confirms the determining importance of the front stages — especially for highly throttled operating conditions. This leads to conclusions regarding the robustness of the overall HPC, which is principally determined by the efficiency and pressure rise of the front stages.

A novel approach to determine splitter vane length for an extremely high hub/tip ratio mixed-flow compressor impeller

2019 ◽  
Vol 234 (4) ◽  
pp. 401-419
Author(s):  
Hang Xiang ◽  
Jiang Chen ◽  
Jinxin Cheng ◽  
Xiancheng Song ◽  
Han Niu
Keyword(s):  
Skin Friction ◽  
Full Length ◽  
Design Flow ◽  
Tip Clearance ◽  
Maximum Efficiency ◽  
Mixed Flow ◽  
Blade Loading ◽  
Blade Number ◽  
Compressor Impeller ◽  
Flow Compressor

This paper presents an approach to determine splitter vane length in radial compressor impellers based on a modified 1D performance prediction model, which considers the effects of splitter vane length and blade number on impeller internal losses. The splitter vane length corresponding to optimum blade number is investigated to achieve the maximum efficiency of a mixed-flow compressor impeller with an extremely high hub/tip ratio. An empirical formula for calculating splitter vane length is proposed. CFD results show that blade number and splitter vane length have a complex coupling interaction which makes it inappropriate to be described by equivalent solidity or effective blade number. 1D results and CFD verification indicate that optimum full-length blade number is 42 and corresponding splitter vane length is 20% of full-length blade length at design flow rate. The impeller peak efficiency mainly depends on minimum loss superposition of blade loading, skin friction and tip clearance. With the increase of splitter vane length and blade number, blade loading loss and clearance loss decline while skin friction loss increases.

Review on the aerodynamics of intermediate compressor duct

2020 ◽  
Vol 14 (4) ◽  
pp. 7446-7468
Author(s):  
Manish Sharma ◽  
Beena D. Baloni
Keyword(s):  
High Pressure ◽  
Pressure Loss ◽  
Flow Analysis ◽  
Outer Wall ◽  
Optimization Techniques ◽  
Optimum Pressure ◽  
Research Areas ◽  
Static Pressure Distribution ◽  
High Pressure Compressor ◽  
Pressure Compressor

In a turbofan engine, the air is brought from the low to the high-pressure compressor through an intermediate compressor duct. Weight and design space limitations impel to its design as an S-shaped. Despite it, the intermediate duct has to guide the flow carefully to the high-pressure compressor without disturbances and flow separations hence, flow analysis within the duct has been attractive to the researchers ever since its inception. Consequently, a number of researchers and experimentalists from the aerospace industry could not keep themselves away from this research. Further demand for increasing by-pass ratio will change the shape and weight of the duct that uplift encourages them to continue research in this field. Innumerable studies related to S-shaped duct have proven that its performance depends on many factors like curvature, upstream compressor’s vortices, swirl, insertion of struts, geometrical aspects, Mach number and many more. The application of flow control devices, wall shape optimization techniques, and integrated concepts lead a better system performance and shorten the duct length.  This review paper is an endeavor to encapsulate all the above aspects and finally, it can be concluded that the intermediate duct is a key component to keep the overall weight and specific fuel consumption low. The shape and curvature of the duct significantly affect the pressure distortion. The wall static pressure distribution along the inner wall significantly higher than that of the outer wall. Duct pressure loss enhances with the aggressive design of duct, incursion of struts, thick inlet boundary layer and higher swirl at the inlet. Thus, one should focus on research areas for better aerodynamic effects of the above parameters which give duct design with optimum pressure loss and non-uniformity within the duct.

scholarly journals Redesign of a High-Pressure Compressor Blade Accounting for Nonlinear Structural Interactions

2014 ◽  
Author(s):  
Alain Batailly ◽  
Mathias Legrand ◽  
Antoine Millecamps ◽  
Sèbastien Cochon ◽  
François Garcin
Keyword(s):  
High Pressure ◽  
Forced Response ◽  
Compressor Blade ◽  
Design Stage ◽  
Blade Design ◽  
Early Integration ◽  
Nonlinear Structural ◽  
High Pressure Compressor ◽  
Structural Interactions ◽  
Pressure Compressor

Recent numerical developments dedicated to the simulation of rotor/stator interaction involving direct structural contacts have been integrated within the Snecma industrial environment. This paper presents the first attempt to benefit from these developments and account for structural blade/casing contacts at the design stage of a high-pressure compressor blade. The blade of interest underwent structural divergence after blade/abradable coating contact occurrences on a rig test. The design improvements were carried out in several steps with significant modifications of the blade stacking law while maintaining aerodynamic performance of the original blade design. After a brief presentation of the proposed design strategy, basic concepts associated with the design variations are recalled. The iterated profiles are then numerically investigated and compared with respect to key structural criteria such as: (1) their mass, (2) the residual stresses stemming from centrifugal stiffening, (3) the vibratory level under aerodynamic forced response and (4) the vibratory levels when unilateral contact occurs. Significant improvements of the final blade design are found: the need for an early integration of nonlinear structural interactions criteria in the design stage of modern aircraft engines components is highlighted.

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