Engineering › Civil and Structural Engineering

Engineering Applied Research

Works Count: 206213

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Description

This cluster of papers focuses on the structural analysis, design optimization, and material properties in various engineering fields such as mechanical, marine, automotive, and aerospace. It includes topics like finite element method, fatigue analysis, numerical simulation, fluid dynamics, and failure analysis.

Keywords

Structural Analysis; Design Optimization; Finite Element Method; Fatigue Analysis; Mechanical Engineering; Numerical Simulation; Fluid Dynamics; Material Properties; Failure Analysis; Product Development

Comparison of wavelet transform and FFT methods in the analysis of EEG signals.

2002-01-01

ML Akin

Thermal performance of oil spray cooling system for in-wheel motor in electric vehicles

2013-12-05

Dong Hyun Lim , Sung Chul Kim

A diffraction beam field expressed as the superposition of Gaussian beams

1988-05-01

J. J. Wen , M. A. Breazeale

The diffraction field of a Gaussian planar velocity distribution is a Gaussian beam function under the condition (ka)2≫1. This property makes a series of Gaussian functions attractive as a possible … The diffraction field of a Gaussian planar velocity distribution is a Gaussian beam function under the condition (ka)2≫1. This property makes a series of Gaussian functions attractive as a possible base function set. The new approach presented enables one to express any axisymmetric beam field in a simple analytical form—the superposition of Gaussian beams about the same axis but with beam waists of different sizes located at different positions along the axis. A computer optimization is used to evaluate the coefficients, as well as the beam waists and their positions. The extreme case of a piston radiator is used to test the approach. Good agreement between a ten-term Gaussian beam solution and the results of numerical integration (or analytical solution on axis) is obtained throughout the beam field: in the farfield, the transition region, and the nearfield. Discrepancies exist only in the extreme nearfield (&lt;0.1 times the Fresnel distance). For surface velocity distributions that are less discontinuous (smoother), the number of terms in the Gaussian beam solution is reduced. In the extreme case of a Gaussian radiator, only one term is needed. The approach, then, reduces the study of any axisymmetric beam field to the study of the much simpler Gaussian beam.

Methods for characterizing CRT displays

1996-05-01

Roy S. Berns

Generalized Frequency Domain Substructure Synthesis

1988-01-01

Bjorn Jetmundsen , Richard L. Bielawa , William G. Flannelly

Literature Review: survey and analysis of the Shock and Vibration literature : Recent Studies in Plate Vibrations: 1981-85 Part II. Complicating Effects

1987-06-01

A.W. Leissa

Corrosion of carbon steel pipes and tanks by concentrated sulfuric acid: A review

2012-02-02

Zehbour Panossian , Neusvaldo Lira de Almeida , Raquel Sousa +2 more

<i>Lens Design Fundamentals</i>

1978-12-01

R. Kingslake , Robert R. Shannon

Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation R. Kingslake, Robert R. Shannon; Lens Design Fundamentals. Physics Today 1 December 1978; 31 … Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation R. Kingslake, Robert R. Shannon; Lens Design Fundamentals. Physics Today 1 December 1978; 31 (12): 51. https://doi.org/10.1063/1.2994870 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentPhysics Today Search Advanced Search

Transducers Using Forced Transitions Between Ferroelectric and Antiferroelectric States

1966-10-01

D. Berlincourt

Abstract : The use of resonant piezoelectric composite structures for acoustic radiation into fluid media is well established. At low frequencies, desirable for long distance acoustic transmission, resonant structures are … Abstract : The use of resonant piezoelectric composite structures for acoustic radiation into fluid media is well established. At low frequencies, desirable for long distance acoustic transmission, resonant structures are extremely large and expensive. Frequency lowering can be accomplished by a variety of means involving use of bending structures or mass-loading, but the resulting transducers are vulnerable to pressure effects due to deep submersion. A possible alternative to present transducer structures is the use of the electric field-forced transition from antiferroelectric to ferroelectric. A number of Pb(Zr, Sn, Ti)O3 compositions have been developed which experience these transitions at relatively low electric field(7-15 kV/cm) and typically generate volume strains near 0.1%. There is therefore not necessarily a requirement for acoustic shielding, and since the developed strain is independent of frequency, resonant structures are not needed. Construction is therefore simplified and the size and weight of low frequency transducers may be reduced. Operating characteristics of the antiferroelectric transducer are discussed in detail, but no large low frequency transducer arrays have yet been built.

Two-Phase Spray Cooling of Hybrid Vehicle Electronics

2009-02-13

Issam Mudawar , D. Bharathan , Kenneth Kelly +1 more

As part of the U.S. Department of Energy's (DOE's) Power Electronics and Electric Machines Program area, the DOE's National Renewable Energy Laboratory (NREL) is currently leading a national effort to … As part of the U.S. Department of Energy's (DOE's) Power Electronics and Electric Machines Program area, the DOE's National Renewable Energy Laboratory (NREL) is currently leading a national effort to develop next-generation cooling technologies for hybrid vehicle electronics. Spray cooling has been identified as a potential solution that can dissipate 150-200 W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> while maintaining the chip temperature below 125degC. This paper explores the viability and implementation of this cooling scheme. First, commercial coolants are assessed for their suitability to this application in terms of thermal, environmental, and safety concerns and material compatibility. In this assessment, HFE-7100 is identified as the optimum coolant in all performance categories. Next, spray models are used to determine the HFE-7100 spray conditions that meet such stringent heat dissipation requirements. These findings are verified experimentally, demonstrating that spray cooling is a viable thermal management solution for hybrid vehicle electronics.

The Effects of Backing and Matching on the Performance of Piezoelectric Ceramic Transducers

1966-03-01

G. Kossoff

An Analysis of the Finite Element Method

1974-07-01

E. I. , Gilbert Strang , George J. Fix

Fully sampled matrix transducer for real time 3D ultrasonic imaging

2004-08-02

Bernie J. Savord , Robert D. Solomon

A 2D array for acquiring 3D images is described. Interconnection methods are presented that connect elements of the array to integrated circuits (ICs) within the transducer. These ICs simultaneously process … A 2D array for acquiring 3D images is described. Interconnection methods are presented that connect elements of the array to integrated circuits (ICs) within the transducer. These ICs simultaneously process signals from ALL elements forming a fully sampled array. Comparisons are made with mechanical and sparse array solutions. Several signal processing options for use within the ICs are presented.

Random Data Analysis and Measurement Procedures

2000-11-20

J S Bendat and A G Piersol

This is a new edition of a book on random data analysis which has been on the market since 1966 and which was extensively revised in 1971. The book has … This is a new edition of a book on random data analysis which has been on the market since 1966 and which was extensively revised in 1971. The book has been a bestseller since. It has been fully updated to cover new procedures developed in the last 15 years and extends the discussion to a broad range of applied fields, such as aerospace, automotive industries or biomedical research.

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The Lifted Index as a Predictor of Latent Instability

1956-12-01

Joseph G. Galway

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Energy beam-solid interactions and transient thermal processing/1984

1985-12-01

W. L. Brown

A Basis for Rational Design of Heat Transfer Apparatus

1915-01-01

Emma Wilson

Research Papers A Basis for Rational Design of Heat Transfer Apparatus E. E. Wilson E. E. Wilson U. S. N. Search for other works by this author on: This Site … Research Papers A Basis for Rational Design of Heat Transfer Apparatus E. E. Wilson E. E. Wilson U. S. N. Search for other works by this author on: This Site PubMed Google Scholar Author and Article Information E. E. Wilson U. S. N. Trans. ASME. Jan 1915, 37: 47-70 (24 pages) https://doi.org/10.1115/1.4059736 Published Online: December 18, 2023 Article history Published: January 1, 1915 Online: December 18, 2023

Ferroelectric thin films

2005-04-23

The area of ferroelectric thin films has expanded rapidly recently with the advent of high quality multi-oxide deposition technology. Advances in thin film quality has resulted in the realization of … The area of ferroelectric thin films has expanded rapidly recently with the advent of high quality multi-oxide deposition technology. Advances in thin film quality has resulted in the realization of new technologies not achievable through classical bulk ceramic processing techniques. An example of this progress is the co-processing of ferroelectric thin films with standard semiconductor silicon and GaAs integrated circuits for radiation hard, non-volatile memory products. While the development of this class of products is still embryonic, the forecasted market potential is rapidly out distancing the combined developmental effort. Historically the greatest use of bulk ferroelectric material has been in sensor technology, utilizing the pyroelectric and piezoelectric properties of the material. By comparison, a relatively small development effort has been reported for ferroelectric thin film senor technology, a field sure to provide exciting advances in the future. The papers in this proceedings volume were presented at the first symposium dedicated to the field of ferroelectric thin films held by the Materials Research Society at the Spring 1990 Meeting in San Francisco, CA, April 16-20, 1990. The symposium was designed to provide a comprehensive tutorial covering the newest advances of ferroelectric thin films, including material systems, new deposition techniques and physical,more » electrical and electro-optic characterization.« less

Lead-free piezoelectric ceramics: Alternatives for PZT?

2007-03-29

Thomas R. Shrout , Shujun Zhang

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Appendix B SAE J6a Ride and Vibration Data Manual

1992-01-01

Thomas Gillespie

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B. A. Auld : Acoustic Fields and Waves in Solids, Vol. 1 and 2, John Wiley, New York and London, 1973, 2 vols., 23.5×16cm.

1974-12-05

御子柴宣夫

Spectral/hp element methods for CFD

1999-12-01

Radiation monitoring system

2021-01-01

Katarina Karadžić

Anna A. Oleshkevich, Specific features of change in enzymate activity in Anna A. Oleshkevich, Specific features of change in enzymate activity in

A Comparison of Unit-Root Test Criteria

1994-10-01

Sastry G. Pantula , Graclela Gonzalez-Farias , Wayne A. Fuller

During the past fifteen years, the ordinary least squares estimator and the corresponding pivotal statistic have been widely used for testing the unit root hypothesis in autoregressive processes.Recently, several new … During the past fifteen years, the ordinary least squares estimator and the corresponding pivotal statistic have been widely used for testing the unit root hypothesis in autoregressive processes.Recently, several new criteriia, based on the maximum likelihood estimators and weighted symmetric estimators, have been proposed.In this article, we describe several different test criteria.Results from a Monte Carlo study that compares the power of the different criteria indicates that the new tests are more powerful against the stationary alternative.Of the procedures studied, the weighted symmetric estimator and the unconditional maximum likelihood estimator provide the most powerful tests against the stationary alternative.As an illustration, we analyze the quarterly change in busine;ss investories.

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IEEE Recommended Practice for Speech Quality Measurements

1969-09-01

Linear Piezoelectric Plate Vibrations

1969-01-01

H. F. Tiersten

Report of Large Motor Reliability Survey of Industrial and Commercial Installations, Part II

1985-01-01

Report of Large Motor Reliability Survey of Industrial and Commercial Installations, Part I

1985-01-01

Piezoelectric Ceramics

1972-03-01

WALTER J. MERZ

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Lens Design Fundamentals

1978-01-01

Lens Design Fundamentals

2010-01-01

An Asymptotic Equivalence of Choice of Model by Cross-Validation and Akaike's Criterion

1977-09-01

M. Stone

Summary A logarithmic assessment of the performance of a predicting density is found to lead to asymptotic equivalence of choice of model by cross-validation and Akaike's criterion, when maximum likelihood … Summary A logarithmic assessment of the performance of a predicting density is found to lead to asymptotic equivalence of choice of model by cross-validation and Akaike's criterion, when maximum likelihood estimation is used within each model.

Ceramics and glasses

1991-01-01

Samuel J Schneider

Provides exhaustive, yet practical information on processing, properties, testing and characterization, design, and applications of various types of ceramics and glasses. The coverage ranges from bricks to super conductors, windows … Provides exhaustive, yet practical information on processing, properties, testing and characterization, design, and applications of various types of ceramics and glasses. The coverage ranges from bricks to super conductors, windows to data transmission lines. Ceramics and Glasses consists of 170 articles divided into 15 major sections. The first section defines and classifies ceramic materials and provides introductory information on each class. Sections two through five deal with processing of ceramic materials. Powder processing, forming methods, sintering, and final shaping (machining) are described. Each article in these sections explains how to produce a 'flaw-free' product. A companion section on glass processing follows. Reliable methods of joining ceramics, a subject critical to the increasing use of structural ceramics are examined in section seven. What follows are two sections devoted to the characterization tools available for studying ceramics and glasses. Processing-structure-property relationships, which are key to the development of improved materials, are introduced. The knowledge required to design structural elements and concepts of design methodology are addressed in section ten. Design practices used for such applications as gas turbine engines, gasoline engines, and whisker-toughened ceramic components are detailed. An extensive review of property data is contained in section eleven. The emphasis is on the design engineering use of the data. The articles in this section serve to bring the users of property information up-to-date and to direct them to the sources of the most useful property data. The broad range of applications for ceramics and glasses are outlined in the volumeAs final four sections. Emphasis has been placed on the use of advanced materials for structural and electrical/electronic applications.

Ceramic Materials and Components for Engines

2001-03-29

Components for Engines , Jürgen G. Heinrich , F. Aldinger

Several ceramic parts have already proven their suitability for serial application in automobile engines in very impressive ways, especially in Japan, the USA and in Germany. However, there is still … Several ceramic parts have already proven their suitability for serial application in automobile engines in very impressive ways, especially in Japan, the USA and in Germany. However, there is still a lack of economical quality assurance concepts. Recently, a new generation of ceramic components, for the use in energy, transportation and environment systems, has been developed. The efforts are more and more system oriented in this field. The only possibility to manage this complex issue in the future will be interdisciplinary cooperation. Chemists, physicists, material scientists, process engineers, mechanical engineers and engine manufacturers will have to cooperate in a more intensive way than ever before. The R&D activities are still concentrating on gas turbines and reciprocating engines, but also on brakes, bearings, fuel cells, batteries, filters, membranes, sensors and actuators as well as on shaping and cutting tools for low expense machining of ceramic components. This book summarizes the scientific papers of the 7th International Symposium Ceramic Materials and Components for Engines. Some of the most fascinating new applications of ceramic meterials in energy, transportation and environment systems are presented. The proceedings shall lead to new ideas for interdisciplinary activities in the future.

Lead-Free Piezoelectrics

2011-11-17

Shashank Priya , Sahn Nahm

A Study on Exhaust Emission Characteristics of Marine Heavy Fuel Oil Boilers for Ships Applying MGO

2025-06-25

Tae‐Ho Lee | Journal of Fisheries and Marine Sciences Education

Optimization of the Desktop CPU's Straight Heatsink via CFD Simulation by Solidworks Flow Simulation

2025-06-24

Md Nazmul Hasan Dipu , Mahbub Hasan Apu , Pritidipto Paul Chowdhury | International Journal of Pioneering Technology and Engineering

The straight heatsink is one of the most common heat transfer components used in desktop CPUs to manage the heat generated by the microprocessor. The study aimed to find the … The straight heatsink is one of the most common heat transfer components used in desktop CPUs to manage the heat generated by the microprocessor. The study aimed to find the optimal fin numbers of the straight heatsink for three different fin thicknesses and compare the masses at these points. For the analysis, the present study used Solidworks® software to create CAD models and perform the CFD simulation. It was found that each of the three different fin thicknesses had a turning point at which the microprocessor’s temperature was at its minimum. The weight of the heatsink was also measured at those turning points. Specifically, the heatsinks with 1 millimeter, 1.5 millimeters, and 2 millimeters thickness had a microprocessor temperature of about 83.52 degrees Celsius, 86.50 degrees Celsius, and 89.25 degrees Celsius, with the weight of approximately 307.80 grams, 388.80 grams, and 448.2 grams. Overall, a 1-millimeter fin thickness with 21 fins configuration for this study was best under the criteria of minimum microprocessor temperature and minimum heatsink mass. Thus, this study successfully demonstrated that optimization of mass and fin thickness of the heatsink was possible to provide better thermal management of the microprocessors of a desktop’s CPU. This study is significant for this era because it provides a panacea for minimum material cost, lightweight, and minimum microprocessor temperature.

Sensitivity Analysis of Factors Affecting Electric Vehicle Energy Consumption under Urban Driving Conditions

2025-06-24

Young-Kap Son , Jeongmin Kim | Journal of the Korean Society of Manufacturing Process Engineers

Research on Multi-Material Lightweight of Electric Vehicle Battery Box

2025-06-23

Junfeng Liu , Yuanchun Kang | SAE International journal of sustainable transportation, energy, environment & policy

<div>To select appropriate lightweight materials and optimize their integration with battery enclosure components for enhanced performance and weight reduction, this study proposes a material selection strategy driven by mechanical property … <div>To select appropriate lightweight materials and optimize their integration with battery enclosure components for enhanced performance and weight reduction, this study proposes a material selection strategy driven by mechanical property indices combined with the CRITIC-weighted TOPSIS method. Initially, a decision matrix incorporating bending stiffness indices was established based on the deformation characteristics of battery enclosures, focusing on commonly used metallic materials. The CRITIC-weighted TOPSIS method was employed to standardize data dimensions, determine objective weight coefficients, and calculate relative closeness coefficients for candidate material screening. Subsequently, sensitivity analysis identified critical components significantly influencing operational conditions, followed by integrated material and dimensional optimization to determine the optimal solution. The optimized battery enclosure achieved a weight reduction of 15.56 kg, with a reduction rate of 33.39%, while maintaining compliance with static/dynamic performance requirements and safety standards. This methodology demonstrates effective coordination between material selection and structural optimization in lightweight design applications.</div>

Geometrical diffraction and the new features in knife-edge diffraction pattern

2025-06-20

Xianming Meng , Ludovic Rapp | Journal of the Optical Society of America A

THE QUESTIONNAIRE SURVEY IN ACTUAL USE STATUS OF PRECEDING LUBRICANT FOR GENERAL CONTRACTOR

2025-06-19

Atsunori MIYATA , Yoshihisa NAKATA , Shuzo OTSUKA +7 more | AIJ Journal of Technology and Design

Design of Turn and Brake Lights of Bicycles Using Advanced Wireless Transmission

2025-06-19

Shu-Han Liao , Liang‐In Lin , Cheng‐Yu Tsai +4 more | Sensors and Materials

ANALYSIS OF THE INSTALLATION RATE AND DESIGN SPECIFICATIONS OF PHOTOVOLTAIC POWER GENERATION EQUIPMENT IN NON-RESIDENTIAL BUILDINGS

2025-06-19

Masato Miyata | AIJ Journal of Technology and Design

A study on the expansion wave diffraction over bodies – ERRATUM

2025-06-19

Vishnu Prasad S. , Anbu Serene Raj C. , Vinoth Paramanantham +2 more | Journal of Fluid Mechanics

Fast Beam Shape Coefficient Computation from Continuous Surface Fields

2025-06-18

Joel Lamberg , L. Lamberg , Zachary Taylor | Optics Letters

Structural Safety Evaluation of a Fairlead Chain Stopper for the Disconnectable Mooring System of Floating Offshore Wind Turbines

2025-06-17

Youngjae Yu , Sang-Hyun Park , Young-Sik Jang +1 more | Journal of Ocean Engineering and Technology

Test rig for submerged transmissions in wave energy converters as a development tool for dynamic sealing systems

2025-06-16

Erland Strömstedt , Anthon Svedström | International Marine Energy Journal

A submerged transmission, fitted with a dynamic sealing system, in a wave energy converter (WEC) serves the purpose of transmitting the force, absorbed by a wave activated body, to an … A submerged transmission, fitted with a dynamic sealing system, in a wave energy converter (WEC) serves the purpose of transmitting the force, absorbed by a wave activated body, to an encapsulated power take-off (PTO) system, while preventing seawater from entering the capsule. Dry generator operation is generally a prerequisite for attaining long technical service life. Little attention seems to be devoted in publications to the study of dynamic sealing systems in WECs, and to test rigs for experimental verification and/or evaluation of the ability/performance of existing dynamic sealing systems in a controlled laboratory environment. This paper begins by presenting some of our earlier research within the focus area of dynamic sealing systems, incl. design considerations and typical operating conditions. This part also presents the 1st laboratory test rig, used for verifying the sealing ability of the piston rod mechanical lead-through design in the 1st and 2nd full-scale experimental WEC prototype from Uppsala University. In 2021 project DynSSWE (Dynamic Sealing Systems for Wave Energy) was initiated. Drawing from experience, the project includes development of a new test rig, representing a tool for further development of dynamic sealing systems. This paper introduces steps in the design and development process of that new test rig, enabling accelerated long-term test runs with a setup of multiple piston rod specimens. The test specimens’ will be surface treated differently with the aim of improving the prospects of a long maintenance free service life. Since the new test rig is in the design stage, seal testing results are not yet reported. The presented work is funded by the Swedish energy agency with the aim of improving subsystem performance in wave energy devices.

Research and Development Status of Micro Gas Turbine for Aviation at Korea Aerospace Research Institute

2025-06-16

Young-Seok Kang , Heeyoon Chung , Dong-Ho Rhee +2 more | The KSFM Journal of Fluid Machinery

Advanced Technology Research and Development on Gas Turbine Engines and Hot Section Components at Korea Aerospace Research Institute

2025-06-16

Dong-Ho Rhee , Hyungmo Kim , Jaiho Kim +6 more | The KSFM Journal of Fluid Machinery

Analysis of Cooling Performance according to Film Cooling Hole Location in the Turbine Cooling Cavity

2025-06-16

Young‐Sik Jo , H. S. Son , Byeongkwon Lim | The KSFM Journal of Fluid Machinery

Commercial Vehicle’s Exhaust Front Pipe Reliability Improvement through Virtual Simulation and Experimental Validation

2025-06-16

Kushal Chandel , Sonu Paroche , Akhilesh Namdev +2 more | SAE technical papers on CD-ROM/SAE technical paper series

<div class="section abstract"><div class="htmlview paragraph">The exhaust front pipe is a critical structural component in commercial vehicles, ensuring the leak-proof flow of exhaust gases into the exhaust after-treatment system while withstanding … <div class="section abstract"><div class="htmlview paragraph">The exhaust front pipe is a critical structural component in commercial vehicles, ensuring the leak-proof flow of exhaust gases into the exhaust after-treatment system while withstanding engine and frame vibrations. To isolate these vibrations, the front pipe is equipped with a flex connector capable of enduring various displacements at frequencies between 8-25 Hz. The position of the flex connector relative to the engine crank axis significantly impacts its structural reliability over its service life. This paper compares the existing design, which features a horizontally positioned flex connector, with a modified design that positions the flex connector vertically and changes the material from SS-304 to SS-321. Finite element analysis was conducted using Nastran software. The fatigue life of the existing flex connector design is approximately 1015 cycles. In contrast, the improved design demonstrates a fatigue life of 1727 cycles, representing a 70% increase in durability compared to the existing design. The newly designed front pipe was then evaluated under the worst-case excitation conditions of 25 mm lateral displacement at 8 Hz frequency using experimental setup. A correlation was established between virtual simulations and experimental validations. Virtual and experimental results conclude that there is a 70% increase in front pipe life when the flex connector is placed vertically with respect to the engine crank axis and SS-321 is used for the flex connector material. This finding is recommended for consideration during vehicle design development.</div></div>

Development and Verification of an Educational Low-Cost HILS Platform for Controller Design of Electromagnetic Suspension Systems

2025-06-16

S. Y. Noh , Yohan Kim , Chang-Hyun Kim | The Transactions of The Korean Institute of Electrical Engineers

A Study on the Application of a 3-Phase 4-Wire Zig-Zag Filter in a 100kW Electric Vehicle Fast Charger

2025-06-16

Jin-Yong Bae | The Transactions of The Korean Institute of Electrical Engineers

EsophyX Z+ Fastener Delivery Device

2025-06-16

| Biomedical Safety & Standards

Analysis and Optimal Design of Sound Transmission Characteristics in Train Air Duct

2025-06-16

Zihao Ren , Jianrun Zhang | Advances in transdisciplinary engineering

This paper mainly studies the noise reduction method of train air conditioning duct, and proposes a composite muffler for train air conditioning duct noise reduction. Firstly, extracting the main air … This paper mainly studies the noise reduction method of train air conditioning duct, and proposes a composite muffler for train air conditioning duct noise reduction. Firstly, extracting the main air duct 3D model in the train air conditioning duct system, use FE-SEA method to anticipate the sound transmission characteristics of the original deflector in the 20∼2000Hz frequency band, and the effectiveness of train noise control is quantified by adopting the standard of sound transmission loss. Then an optimization scheme is proposed, which uses a composite muffler instead of the common deflector, and further improves the muffler performance by changing the relevant parameters of the micro-perforated plate of the composite muffler. Finally, the final optimization scheme is determined by comparing the above simulation results, and the actual test results are used to verify the effectiveness of the final optimization scheme. Finally, the final optimization scheme is determined by comparing the above simulation results, and the effectiveness of the final optimization scheme is verified by the physical test results.

Simulation Analysis of Two-Phase Flow in Fluid Throat of Burner for Thermal Fatigue Testing

2025-06-16

Junjie Sun , Jiaqi Tian , Yuanjun Zhang +1 more | Advances in transdisciplinary engineering

To address the issue of testing single component under multiple working conditions in thermal fatigue tests of aircraft engine parts, it is of great significance to regulate the pressure inside … To address the issue of testing single component under multiple working conditions in thermal fatigue tests of aircraft engine parts, it is of great significance to regulate the pressure inside the combustor by injecting secondary flow at the throat of the combustor. In this paper, a discrete phase model (DPM) of water is introduced to simulate the gas-liquid two-phase flow field at the throat of the combustor. The effects of water, water vapor, and two-phase flow of water and water vapor on pressure regulation are compared, and the basic rules of jet flow rate and angle on pressure regulation are analyzed, providing guidance for thermal machine fatigue tests and greatly reducing test costs. This work provides a new approach for combustor adaptive pressure regulation.

Probabilistic Damage Tolerance Assessment of Turbine Disk Multiple Bolt Holes Considering Probability of Detection

2025-06-16

Weihan Kong , Rongqiao Wang , Xi Liu +5 more | Advances in transdisciplinary engineering

Probabilistic damage tolerance assessment (PDTA) was performed on aero-engine turbine disk multiple bolt holes. Firstly, the probability of detection (PoD) test of fluorescence penetration inspection (FPI) was designed and carried … Probabilistic damage tolerance assessment (PDTA) was performed on aero-engine turbine disk multiple bolt holes. Firstly, the probability of detection (PoD) test of fluorescence penetration inspection (FPI) was designed and carried out, and the pod curves were established to quantify the effect of oxidation on the PoD; then, the PDTA process considering the influence of the number of bolt holes was established, and the influence of the maintenance cycle and the number of bolt holes on the reliability was evaluated, which provided a reference for engineering design. The results show that the length of FGH96 cracks corresponding to 90% detection probability at 95% confidence level is 1.83mm; the length of oxidized FGH96 cracks corresponding to 90% detection probability at 95% confidence level is 2.53mm. At higher reliability levels, reliability for the same lifetime generally decreases with increasing maintenance cycles and the number of hazardous areas.

Optimization Design of Typical Electrical Components for Hybrid Electric Propulsion Aircraft

2025-06-16

Haoliang Yu , Tao Lei , Shuhao Deng +3 more | Advances in transdisciplinary engineering

In recent years, as the secondary onboard energy sources of traditional aircraft such as hydraulic, mechanical, and pneumatic systems are gradually unified into electrical energy, forming more-electric or all-electric aircraft, … In recent years, as the secondary onboard energy sources of traditional aircraft such as hydraulic, mechanical, and pneumatic systems are gradually unified into electrical energy, forming more-electric or all-electric aircraft, the exploration of hybrid electric propulsion technology for aircraft has deepened. This article proposes an optimization method for evaluating the power system architecture of electric propulsion aircraft that combines parametric modeling of typical components with optimization algorithms. Initially, it outlines the model establishment process for the main components of the power system under multiple constraints, including motors, inverters, and conductors. On this basis, it presents the Pareto curves of motor weight and efficiency at different voltage levels and the trade-offs in voltage level selection for cables made of different materials. Finally, a simplified system-level architecture modeling and optimization study of the motor-inverter-cable system was conducted, providing valuable contributions and support for the design of the power system in large hybrid aircraft.

Structural Safety Assessment Based on Stress-Life Fatigue Analysis for T/C Nozzle Ring Blade

2025-06-15

Won-Kyung Jeon , Haechang Jeong | Journal of Marine Science and Engineering

The performance of the turbocharger nozzle ring is a key factor in the overall operation of the main engine of the ship. Minimizing failure and damage caused by high exhaust … The performance of the turbocharger nozzle ring is a key factor in the overall operation of the main engine of the ship. Minimizing failure and damage caused by high exhaust gas temperature and pressure is essential. As a first step toward improving turbocharger safety, this study performed 3D scanning of an aged nozzle ring to obtain its precise geometry and developed a corresponding numerical model. The boundary conditions of the numerical model were defined by the exhaust gas temperature and pressure at various engine output loads. Structural safety was assessed using static structural and stress-life fatigue analyses. A sharp increase in maximum equivalent stress and strain was observed at output loads of 85% and higher. At 25% load, the maximum fatigue life indicated 1.76 × 108 cycles, while at 100% load, the maximum damage index reached 1. A field performance test conducted at 85% of the main engine’s output load revealed severe damage under high-load conditions. Specifically, damage occurred at the contact area between the outer hoop and the tip of the blade’s trailing edge. This observed damage pattern closely aligned with the results predicted by the fatigue life analysis. The validity of the present study was confirmed through a comparative analysis of the fatigue life predictions and the field test results.

Development of an Outdoor Autonomous Driving Robot System for Urban Park Cleaning

2025-06-15

Kuk-Won Ko | Journal of The Korean Society of Manufacturing Technology Engineers

Improved Correlation Optimized Virtual Orbital Algorithm for Plane-Wave Full Configuration Interaction Calculations

2025-06-13

Mengdi Qiu , Zhenlin Zhang , Zhiyuan Zhang +4 more | Journal of Chemical Theory and Computation

Full configuration interaction (FCI) calculations have historically faced significant challenges in dealing with periodic systems. The plane-wave basis sets are valued for their efficiency and broad applicability in various computational … Full configuration interaction (FCI) calculations have historically faced significant challenges in dealing with periodic systems. The plane-wave basis sets are valued for their efficiency and broad applicability in various computational physics and chemistry simulations. Because of their natural periodicity, the plane-wave basis sets offer a potential solution to this problem. Moreover, FCI can address the limitations of widely used methods, such as density functional theory (DFT) with plane-wave basis sets, in accurately describing strongly correlated systems. However, the large basis set nature of the plane-wave makes them unsuitable for direct application in FCI calculations. To address this challenge, we propose an improved algorithm based on the correlation-optimized virtual orbital (COVOS) framework. By incorporating rotational matrices to enhance the active space dimension and optimizing orbitals through iterative coupled processes, we successfully compress the extensive plane-wave basis set into a manageable number of virtual orbitals suitable for FCI calculations while retaining most of the original basis set characteristics. We apply this method to supercell calculations and potential energy curves of periodic metallic systems. To further validate our approach, we test it on nonperiodic small molecular systems and compare the results with those obtained from DFT, second-order Møller-Plesset perturbation theory (MP2), random phase approximation (RPA), FCI calculations using the 6-31G or cc-pVDZ basis sets, and the original COVOS algorithm. The improved COVOS framework demonstrates significant advantages in convergence and correlation description over the original method. Furthermore, we observe metal divergence issues in MP2 calculations for certain metallic systems and note that RPA may overestimate the correlation energy of such systems. These findings underscore the importance of achieving FCI calculations with plane-wave basis sets.

Experimental Study on Hull Surface Pressure, Motion Response, and Added Resistance Measurements of a KLNG in Regular Waves

2025-06-13

Dong-Min Park , Seunghyun Hwang , Yong-Ju Kwon | Journal of the Society of Naval Architects of Korea

A Computational Study on the Excitation Forces of Partially Submerged Propellers for High-Speed Boats

2025-06-13

Fangshuai Wei , Yujun Liu , Wang Ji +2 more | Journal of Marine Science and Engineering

During high-speed navigation, boat propellers often become partially exposed due to elevated sailing speeds. This condition results in a unique operational scenario where propellers are only partially submerged. Conducting computational … During high-speed navigation, boat propellers often become partially exposed due to elevated sailing speeds. This condition results in a unique operational scenario where propellers are only partially submerged. Conducting computational studies on the excitation of propellers under such circumstances is essential for optimizing the dynamic performance of the shafting system. A theoretical calculation method for propeller performance was developed based on the principles of fluid dynamics relevant to water entry, leading to a computational method for determining excitation forces in this specific operational condition. This method was subsequently refined through appropriate adjustments using ANSYS Fluent software to simulate the behavior of partially submerged propellers. The findings highlighted the accuracy of the proposed model in predicting the pulsation of six force components across three distinct directions: along the propeller shaft, vertical, and lateral. Specifically, for a single blade (Blade 1), the pulsation amplitude of the vertical force (Fx) constituted 82.1% of its maximum peak magnitude and equated to 57.5% of the blade’s mean thrust. Analogously, the lateral force (Fz) pulsation amplitude represented 53.3% of its maximum peak magnitude and 40.0% of the mean thrust. These findings indicate the presence of significant unsteady hydrodynamic loads. Furthermore, a visualization approach was presented to analyze blade load phasing, offering insights relevant to the arrangement of blades on partially submerged propellers.

Multi-Objective Optimization Technique-based Inverse Design of Honeycomb Lattice Steel Damper Considering Target Internal Force

2025-06-13

Jinhong Bang , Jaehoon Bae , Sanghoon Kim +3 more | Transactions of the Korean Society of Mechanical Engineers A

A Study on Propulsion Performance and Cavitation Test Method of Composite Propellers Using a Large Cavitation Tunnel

2025-06-13

Sung‐Hoon Kim , Chan‐Jin Park , Hyoung Seok Lee +4 more | Journal of the Society of Naval Architects of Korea

Numerical Study on the Open Water Performance of a Toroidal Propeller Using CFD

2025-06-13

Myeong-Eun Kim , So-Won Jung , Bu-Geun Paik +4 more | Journal of the Society of Naval Architects of Korea

Optimal Design of Linear Feeder for Secondary Battery Functional Parts AI Inspection Equipment Using Vibration Analysis-based Response Surface Methodology

2025-06-13

Jeongho Han , Joonho Bang , Seung-Woo Ra +3 more | Journal of the Korean Society for Precision Engineering

Optimum design of liquefied petroleum gas (LPG) composite hybrid and non-hybrid cylinders by genetic algorithm for maximum failure pressure

2025-06-12

Brahim Mouchane , Süleyman Baştürk | International Journal of Mechanics and Materials in Design

Coaxial local exhaust device

2025-06-11

Yu. A. Sivachenko , Oleg Zaytsev , Aleksey Burtsev | Proceedings of Southwest State University

Purpose of research . For the geometric parameters of the device obtained as a result of studies, which improve the conditions for the formation of the suction flow. and the … Purpose of research . For the geometric parameters of the device obtained as a result of studies, which improve the conditions for the formation of the suction flow. and the proposed design solutions of an exhaust device for local ventilation systems to remove harmful emissions during plasma metalworking, which make it possible to improve working conditions and perform industrial tests of the device sample. Methods. Numerical modeling was performed to obtain a spatial representation of the current lines and velocity fields. Physical modeling methods were used to obtain dependencies that formulate methods for calculating the aerodynamic and ecological-energy parameters of the resulting flow during the interaction of the flow, the resulting hazards with the suction flow and the radial limiting ramjet. Results . Confirmation of theoretical studies of the design of a local exhaust device with a limiter diffuser designed to form a limiting radial jet and experimental studies on tests of an industrial sample of a local exhaust device of the proposed design have been obtained. Conclusion. The recommended local coaxial exhaust device of the proposed design can significantly improve the microclimate parameters at stationary plasma cutting sites for a wide range of machines for automated processing of various metals during plasma cutting of metals. Based on experimental and theoretical studies of a coaxial exhaust device, which implements the principle of removing hazards from the plane below the workpiece being processed, limited by a radially directed distributing flow, axial velocity values for various air flow rates with an optimal ratio of suction and limiting flows β for the patented design of a local exhaust device were obtained for the first time.

A study on the expansion wave diffraction over bodies

2025-06-10

Anbu Serene Raj C. , Vinoth Paramanantham , Athira C.M. +2 more | Journal of Fluid Mechanics

The investigation of shock/blast wave diffraction over various objects has garnered significant attention in recent decades on account of the catastrophic changes that these waves inflict on the environment. Equally … The investigation of shock/blast wave diffraction over various objects has garnered significant attention in recent decades on account of the catastrophic changes that these waves inflict on the environment. Equally important flow phenomena can occur when the moving expansion waves diffract over bodies, which has been hardly investigated. To investigate the effect of expansion wave diffraction over different bodies, we conducted shock tube experiments and numerical simulations to visualise the intricate wave interactions that occur during this process. The current investigation focuses on the phenomenon of expansion wave diffraction across three distinct diffracting configurations, namely the bluff, wedge and ogive bodies. The diffraction phenomenon is subsequently investigated under varying expansion wave strengths through the control of the initial diaphragm rupture pressure ratios. The shock waves generated by the expansion wave diffraction in the driver side of the shock tube, which was initially identified in numerical simulations by Mahomed & Skews (2014 J. Fluid Mech. , vol. 757, pp. 649–664), have been visualised in the experiments. Interesting flow features, such as unsteady shock generation, transition, and symmetric/asymmetric vortex breakdown, have been observed in these expansion flows. An in-depth analysis of such intricate flow features resulting from expansion wave diffraction is performed and characterised in the current study.