Application of Fuzzy Logic to Axial Compressor Performance Map Prediction

2007 ◽  
Author(s):  
Kaveh Ghorbanian ◽  
Mohammad Gholamrezaei
Keyword(s):  
Fuzzy Logic ◽  
Axial Compressor ◽  
Optimization Procedure ◽  
Time Frame ◽  
Learning Capability ◽  
Design Variables ◽  
Performance Map ◽  
Compressor Performance ◽  
Short Time ◽  
Fuzzy Logic Technique

The present paper applies fuzzy logic technique to predict the performance map of an axial compressor. This technique relies on employing the information of a data curve in concert with the information at the design point. Further, the learning capability of ANN technique is integrated to the potential of fuzzy logic. A comparison of the predicted results with experimental data reveals a very good agreement. The proposed technique has not only the capability to model the nonlinear surge line as well as the kink in a classical compressor performance map but also it can be used as an alternative tool to foresee the effect of modification of design variables, as well as to guide the design optimization procedure in a short time frame.

The Stacking of Compressor Stage Characteristics to Give an Overall Compressor Performance Map

1962 ◽  
Vol 13 (4) ◽  
pp. 349-367 ◽  
Author(s):  
M. D. C. Doyle ◽  
S. L. Dixon
Keyword(s):  
Axial Compressor ◽  
Compressor Stage ◽  
Individual Stage ◽  
Optimum Performance ◽  
Method Of Calculation ◽  
Multi Stage ◽  
Performance Map ◽  
Compressor Performance ◽  
Overall Performance ◽  
The Individual

SummaryA method of calculation is developed to compute the overall performance of a multi-stage axial compressor, from a knowledge of the individual stage characteristics, by a “stacking” technique. Compressor models are designed and their overall performance calculated. These results are compared to show, qualitatively, the effect of alterations in design and stage performance on overall performance and to find how compressors should be designed for optimum performance.

Compressor Fouling Modeling: Relationship Between Computational Roughness and Gas Turbine Operation Time

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Francesco Melino ◽  
Mirko Morini ◽  
Antonio Peretto ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Fluid Dynamics ◽  
Surface Roughness ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Axial Compressor ◽  
Operation Time ◽  
Compressor Stage ◽  
Performance Map ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance

Gas turbine axial compressor performance is heavily influenced by blade fouling. As a result, the gas turbines efficiency and producible power output decrease. Performance degradation of an axial compressor stage due to fouling can be analyzed by means of simulation through computational fluid dynamics (CFD) codes. Usually these methods reproduce the deteriorated blades by increasing their surface roughness and thickness. Another approach is the scaling of compressor stage performance maps. A model based on stage-by-stage techniques was presented in a previous work. This model is able to estimate the modifications of the overall compressor performance map as a function of the operating hours. The aim of the present study is to combine these two different approaches in order to relate the increase of blade computational surface roughness with compressor operating hours.

Compressor Fouling Modeling: Relationship Between Computational Roughness and Gas Turbine Operation Time

2011 ◽  
Author(s):  
Francesco Melino ◽  
Mirko Morini ◽  
Antonio Peretto ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Fluid Dynamics ◽  
Surface Roughness ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Axial Compressor ◽  
Operation Time ◽  
Compressor Stage ◽  
Performance Map ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance

Gas turbine axial compressor performance is heavily influenced by blade fouling; as a result, the gas turbines efficiency and producible power output decrease. Performance degradation of an axial compressor stage due to fouling can be analyzed by means of simulation through Computational Fluid Dynamics (CFD) codes. Usually these methods reproduce the deteriorated blades by increasing their surface roughness and/or thickness [1]. Another approach is the scaling of compressor stage performance maps. A model based on stage-by-stage techniques was presented in a previous work. This model is able to estimate the modifications of the overall compressor performance map as a function of the operating hours [2]. The aim of the present study is to combine these two different approaches in order to relate the increase of blade computational surface roughness with compressor operating hours.

scholarly journals Axial Compressor Mean-Line Analysis: Choking Modelling and Fully-Coupled Integration in Engine Performance Simulations

2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Ioannis Kolias ◽  
Alexios Alexiou ◽  
Nikolaos Aretakis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Axial Compressor ◽  
Engine Performance ◽  
Engine Model ◽  
Multi Stage ◽  
Transient Simulations ◽  
Full Knowledge ◽  
Compressor Performance ◽  
First Time ◽  
Performance Calculation ◽  
Fully Coupled

A mean-line compressor performance calculation method is presented that covers the entire operating range, including the choked region of the map. It can be directly integrated into overall engine performance models, as it is developed in the same simulation environment. The code materializing the model can inherit the same interfaces, fluid models, and solvers, as the engine cycle model, allowing consistent, transparent, and robust simulations. In order to deal with convergence problems when the compressor operates close to or within the choked operation region, an approach to model choking conditions at blade row and overall compressor level is proposed. The choked portion of the compressor characteristics map is thus numerically established, allowing full knowledge and handling of inter-stage flow conditions. Such choking modelling capabilities are illustrated, for the first time in the open literature, for the case of multi-stage compressors. Integration capabilities of the 1D code within an overall engine model are demonstrated through steady state and transient simulations of a contemporary turbofan layout. Advantages offered by this approach are discussed, while comparison of using alternative approaches for representing compressor performance in overall engine models is discussed.

scholarly journals Polyethylene Migration from Food Packaging on Cheese Detected by Raman and Infrared (ATR/FT-IR) Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3872
Author(s):  
Klytaimnistra Katsara ◽  
George Kenanakis ◽  
Zacharias Viskadourakis ◽  
Vassilis M. Papadakis
Keyword(s):  
Vibrational Spectroscopy ◽  
Food Packaging ◽  
Time Frame ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Ft Ir ◽  
Comparative Results ◽  
Short Time ◽  
And Storage ◽  
Ft Ir Spectroscopy

For multiple years, food packaging migration has been a major concern in food and health sciences. Plastics, such as polyethylene, are continuously utilized in food packaging for preservation and easy handling purposes during transportation and storage. In this work, three types of cheese, Edam, Kefalotyri and Parmesan, of different hardness were studied under two complementary vibrational spectroscopy methods, ATR-FTIR and Raman spectroscopy, to determine the migration of low-density polyethylene from plastic packaging to the surface of cheese samples. The experimental duration of this study was set to 28 days due to the degradation time of the selected cheese samples, which is clearly visible after 1 month in refrigerated conditions at 4 °C. Raman and ATR-FTIR measurements were performed at a 4–3–4–3 day pattern to obtain comparative results. Initially, consistency/repeatability measurement tests were performed on Day0 for each sample of all cheese specimens to understand if there is any overlap between the characteristic Raman and ATR-FTIR peaks of the cheese with the ones from the low-density polyethylene package. We provide evidence that on Day14, peaks of low-density polyethylene appeared due to polymeric migration in all three cheese types we tested. In all cheese samples, microbial outgrowth started to develop after Day21, as observed visually and under the bright-field microscope, causing peak reverse. Food packaging migration was validated using two different approaches of vibrational spectroscopy (Raman and FT-IR), revealing that cheese needs to be consumed within a short time frame in refrigerated conditions at 4 °C.

scholarly journals Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
John Clifton-Brown ◽  
Kai-Uwe Schwarz ◽  
Danny Awty-Carroll ◽  
Antonella Iurato ◽  
Heike Meyer ◽  
...  
Keyword(s):  
Significant Contribution ◽  
Perennial Grass ◽  
Time Frame ◽  
Eastern Asia ◽  
Germplasm Collections ◽  
Naturally Occurring ◽  
Wide Range ◽  
Yield Quality ◽  
Short Time ◽  
Commercial Expansion

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

Compressor Performance and Operability in Swirl Distortion

2010 ◽  
Author(s):  
Yogi Sheoran ◽  
Bruce Bouldin ◽  
P. Murali Krishnan
Keyword(s):  
Gas Turbine ◽  
Complex Geometry ◽  
Full Range ◽  
Axial Compressor ◽  
Cfd Model ◽  
Generator System ◽  
Sliding Mesh ◽  
Wide Range ◽  
Compressor Performance ◽  
The Impact

Inlet swirl distortion has become a major area of concern in the gas turbine engine community. Gas turbine engines are increasingly installed with more complicated and tortuous inlet systems, like those found on embedded installations on Unmanned Aerial Vehicles (UAVs). These inlet systems can produce complex swirl patterns in addition to total pressure distortion. The effect of swirl distortion on engine or compressor performance and operability must be evaluated. The gas turbine community is developing methodologies to measure and characterize swirl distortion. There is a strong need to develop a database containing the impact of a range of swirl distortion patterns on a compressor performance and operability. A recent paper presented by the authors described a versatile swirl distortion generator system that produced a wide range of swirl distortion patterns of a prescribed strength, including bulk swirl, twin swirl and offset swirl. The design of these swirl generators greatly improved the understanding of the formation of swirl. The next step of this process is to understand the effect of swirl on compressor performance. A previously published paper by the authors used parallel compressor analysis to map out different speed lines that resulted from different types of swirl distortion. For the study described in this paper, a computational fluid dynamics (CFD) model is used to couple upstream swirl generator geometry to a single stage of an axial compressor in order to generate a family of compressor speed lines. The complex geometry of the analyzed swirl generators requires that the full 360° compressor be included in the CFD model. A full compressor can be modeled several ways in a CFD analysis, including sliding mesh and frozen rotor techniques. For a single operating condition, a study was conducted using both of these techniques to determine the best method given the large size of the CFD model and the number of data points that needed to be run to generate speed lines. This study compared the CFD results for the undistorted compressor at 100% speed to comparable test data. Results of this study indicated that the frozen rotor approach provided just as accurate results as the sliding mesh but with a greatly reduced cycle time. Once the CFD approach was calibrated, the same techniques were used to determine compressor performance and operability when a full range of swirl distortion patterns were generated by upstream swirl generators. The compressor speed line shift due to co-rotating and counter-rotating bulk swirl resulted in a predictable performance and operability shift. Of particular importance is the compressor performance and operability resulting from an exposure to a set of paired swirl distortions. The CFD generated speed lines follow similar trends to those produced by parallel compressor analysis.

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