Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.5
2.7
Journals
Applied Sciences
Special Issues
Turbomachinery: Design and Applied Sciences
share announcement

Turbomachinery: Design and Applied Sciences

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Mechanical Engineering".

Deadline for manuscript submissions: closed (25 April 2022) | Viewed by 7990

Special Issue Editor

Dr. Keun Ryu

E-Mail Website
Guest Editor
Department of Mechanical Engineering, Hanyang University, Ansan 15588, Gyeonggi-do, Republic of Korea
Interests: turbomachinery rotordynamics; rotating machinery diagnostics and vibration; bearings, seals, and dampers for turbomachinery; advanced turbomachinery with Improved stability; cryogenic bearings for liquid rocket engine turbopumps; oil-free turbomachinery; rocket engine turbopumps; electrically assisted turbomachinery; automotive turbochargers; high-speed electric motors/generators; space tribology
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Turbomachinery in future propulsion and power systems with low emission and high performance requires an oil-free shaft support system with improved efficiencies and reliability, along with savings in long-interval maintenance expenses.

The current Special Issue invites archival-quality papers in the broad aspects of component and system technologies for oil-free turbomachinery, such as automotive turbochargers, charging systems for fuel cell applications, compressors, blowers, fans, micro gas turbines, and motors/generators. The Issue welcomes review papers and discussions of published papers. Topics to be considered include, but are not restricted to:

  • Recent research and development of oil-free shaft support systems (compliant-surface gas bearings, rigid-surface gas bearings, hydrostatic bearings, hybrid bearings, magnetic bearings, advanced solid lubricants, dampers, and seals);
  • Predictions and measurements of the performance of oil-free turbomachinery;
  • Rotordynamics of oil-free turbomachinery;
  • Tribology for oil-free turbomachinery;
  • Thermal management of oil-free turbomachinery;
  • Failure analysis of components and systems in oil-free turbomachinery;
  • Thrust load balance and seals in oil-free turbomachinery;
  • Test rig development for component-level and system-level evaluation;
  • Experimental identification of static/dynamic force coefficients of shaft support elements (bearings, seals, and dampers);
  • Modeling, predictions, fabrication, measurements, and testing of mechanical components/elements in oil-free turbomachinery;
  • Experimental uncertainty quantification of mechanical components/elements in oil-free turbomachinery;
  • Measurements in extreme operating conditions (high temperature, harsh vibration, and high rotor speed);
  • Experimental methods and sensors for oil-free turbomachinery;
  • Technical approaches for mass-production commercial applications.

Prof. Dr. Keun Ryu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Turbomachinery
  • Performance
  • Rotordynamics
  • Vibration
  • Bearings
  • Dampers
  • Seals
  • Tribology
  • Thermal management
  • Multiphysics

Published Papers (4 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

13 pages, 4616 KiB  
Article
Research on Predicting Remain Useful Life of Rolling Bearing Based on Parallel Deep Residual Network
by Xingang Wang, Dongkai Qiao, Kaizhong Han, Xiaohui Chen and Ziqiu He
Appl. Sci. 2022, 12(9), 4299; https://doi.org/10.3390/app12094299 - 24 Apr 2022
Cited by 5 | Viewed by 1318
Abstract
The prediction of bearing remaining useful life (RUL) plays a pivotal role in ensuring the safe operation of machinery and reducing maintenance loss. Traditional prediction methods only consider the features of one domain or integrate the features of multiple domains into a one-dimensional [...] Read more.
The prediction of bearing remaining useful life (RUL) plays a pivotal role in ensuring the safe operation of machinery and reducing maintenance loss. Traditional prediction methods only consider the features of one domain or integrate the features of multiple domains into a one-dimensional sequence as the model input, which leads to some inaccuracy in prediction. In order to improve the prediction accuracy, a bearing RUL prediction method based on the parallel deep residual convolution neural network (P-ResNet), which is considered both time-domain features and time–frequency features, is proposed in this paper. Synchronous wavelet transform (SWT) is adopted to extract time–frequency features from original vibration signals. Both the time domain features and time–frequency domain features after dimension reduction by PCA are used as input to P-ResNet, which contains two series of parallel convolution operations to learn the time–frequency features and time-domain features, respectively, to ensure the comprehensiveness of information-bearing degradation. The residual layers were added to enhance the learning ability of time–frequency features. Kalman filter algorithm was used to smooth the prediction results. The IEEE PHM 2012 Data Challenge datasets were used as data sources for model training and prediction. Compared with the traditional convolutional neural network (CNN), the P-ResNet model maintains the synchronization of global and local information and has a stronger learning ability. The experiment data validate the effectiveness of the proposed method, and the comparison between the prosed methods and the others proves the superiority of the proposed method. Full article
(This article belongs to the Special Issue Turbomachinery: Design and Applied Sciences)
►▼ Show Figures

Figure 1

21 pages, 9476 KiB  
Article
Design Approach and Mechanism Analysis for Cavitation-Tolerant Torque Converter Blades
by Zilin Ran, Wenxing Ma and Chunbao Liu
Appl. Sci. 2022, 12(7), 3405; https://doi.org/10.3390/app12073405 - 27 Mar 2022
Cited by 4 | Viewed by 1532
Abstract
As the development of hydrodynamic torque converters (HTCs) points toward increasing the pump input power and pump rotation speed, the negative effects of cavitation are worsening. Most studies focus on suppressing fluid machinery cavitation to attenuate the negative effects of cavitation, such as [...] Read more.
As the development of hydrodynamic torque converters (HTCs) points toward increasing the pump input power and pump rotation speed, the negative effects of cavitation are worsening. Most studies focus on suppressing fluid machinery cavitation to attenuate the negative effects of cavitation, such as noise, vibration, and blade damage. Therefore, we proposed two stator cavitation suppression slotting methods to suppress stator cavitation in HTCs: (1) slotting both sides of the pressure and suction sides and (2) slotting one side of the suction side. The key design parameters are analyzed, including the slot width and slot position of the stator blade. Findings show that a wider slot enlarges the mass flow rate ventilation through the slot, thus reducing the cavitation risk but decreasing the hydrodynamic performance. The most effective slot position for the second proposed method (slotting one side of the suction side) is between S0.15 (stator suction side dimensionless distance 0.15 location) and S0.6 (stator blade suction side); here, the stator cavitation can be suppressed completely. The capacity factor (Tbg) and torque ratio (K) are decreased by 6.81% and 3.23%, respectively, under the stalling speed ratio, whereas the stator cavitation almost completely disappears. Therefore, the new method of slotting one side of the stator suction side completely suppresses the stator cavitation and significantly shortens the cavitation duration. The new method of slotting one side of the blade suction side can serve as a reference for turbomachinery design. Full article
(This article belongs to the Special Issue Turbomachinery: Design and Applied Sciences)
►▼ Show Figures

Figure 1

20 pages, 7928 KiB  
Article
Rotordynamic Analysis of Piezoelectric Gas Foil Bearings with a Mechanical Preload Control Based on Structural Parameter Identifications
by Jisu Park, Donghee Kim and Kyuho Sim
Appl. Sci. 2021, 11(5), 2330; https://doi.org/10.3390/app11052330 - 05 Mar 2021
Cited by 10 | Viewed by 1828
Abstract
This paper presents a rotordynamic analysis and experimental characterization of a novel concept of a controllable gas foil bearing (C-GFB) with piezoelectric (PZT) actuators. The C-GFB consists of bump foil structures and three PZT actuators, and the PZT actuators push the bump foil [...] Read more.
This paper presents a rotordynamic analysis and experimental characterization of a novel concept of a controllable gas foil bearing (C-GFB) with piezoelectric (PZT) actuators. The C-GFB consists of bump foil structures and three PZT actuators, and the PZT actuators push the bump foil structures in different displacements according to the driving voltage, enabling preload control. In order to predict the piezoelectric preload according to the driving voltage, an equivalent spring model for PZT actuators and foil structures is introduced. In addition, PZT parameters (a piezoelectric constant and stiffness) are measured through parameter identification tests using a latch. Next, static lubrication analysis for C-GFB reveals that the gas-film pressure reduces the effect of piezoelectric preload by up to a maximum of 11%, because the piezoelectric actuator has structural compliance so that it is structurally deformed by the pressure. Finally, nonlinear orbit simulation is performed, and the performance of real-time vibration control of C-GFB is evaluated. The real-time preload control is carried out at ~32.6 krpm, where the rotordynamic instability sufficiently occurs. As the driving voltage increases, the instability suppression and delay effect increase. In particular, when controlled at 150 V, the onset speed of the instability increases to 79.1 krpm. Consequently, this study demonstrates that the GFB with piezoelectric preloads is a simple, effective, and real-time method to improve the rotordynamic stability. Full article
(This article belongs to the Special Issue Turbomachinery: Design and Applied Sciences)
►▼ Show Figures

Figure 1

19 pages, 5899 KiB  
Article
Rotordynamic Analysis of Gas Foil-Polymer Bearings Based on a Structural Elasticity Model of Polymer Layer along with Static-Load Deflection Tests
by Jisu Park and Kyuho Sim
Appl. Sci. 2021, 11(4), 1789; https://doi.org/10.3390/app11041789 - 18 Feb 2021
Cited by 5 | Viewed by 2372
Abstract
In this study, rotordynamic analysis is performed using a simple structural model for the polymer layer of gas foil-polymer bearing (GFPB) composed of an accumulated bump foil and a polymer layer with high structural damping. The simple model that considers the elastic behavior [...] Read more.
In this study, rotordynamic analysis is performed using a simple structural model for the polymer layer of gas foil-polymer bearing (GFPB) composed of an accumulated bump foil and a polymer layer with high structural damping. The simple model that considers the elastic behavior of a cylinder-shaped polymer layer is introduced, and the structural stiffness of the layer is estimated based on Hooke’s law for differential elements in the layer. In addition, the simple model is coupled with the structural stiffness of the bump foil in consideration with a series relationship, which represents the structural model of GFPBs. A GFPB with thickness of 2 mm is fabricated, and the structural model is validated via static-load deflection tests for the GFPB. As a result of model validation, the proposed model is found to be effective in predicting the elastic behavior under the lightly loaded condition of GFPB. Next, the static performances of GFPBs, namely, gas-film pressure, thickness, and journal positions with respect to different polymer layer thickness, are analyzed to evaluate rotordynamic stability of GFPBs. The results indicate that high thickness yields an increase in damping and a decrease in cross-coupled effects. Specifically, in this study, 3 mm-thick polymer gives the best stability performance given the predicted effective damping results. As a result, this work provides a reasonable model for structural elasticity of GFPBs and lays a foundation for the widespread use of GFPBs. Full article
(This article belongs to the Special Issue Turbomachinery: Design and Applied Sciences)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-4
Back to TopTop