bluuebunny/crossref_metadata_2025_split huggingface dataset:
FE Analysis of the Dynamic Characteristics of the Human Finger Pad in Contact With Objects With/Without Surface Roughness
Authors: Maeno Takashi , Kobayashi Kazumi 
Published: January 2022

Abstract
We calculate the transient dynamic response of human finger skin and the distribution of the strain energy density at the tactile receptors focusing on the effect of epidermal ridges on tactile sensation. Using a FE (finite element) model which we create from geometric and material properties measured from an actual human index finger, we introduce a method of dynamic contact analysis which we use to analyze the dynamic contact between a finger with/without epidermal ridges and an object with/without surface roughness. It is found that the epidermal ridges increase the sensitivity of the tactile receptors. The presence of epidermal ridges change either the distribution pattern or the amplitude of the strain energy density at the tactile receptors. It is also found that the Meissner’s corpuscles are relatively sensitive for detecting the surface roughness, whereas Merkel’s discs are relatively sensitive for detecting indentations in objects.
Education in Mechatronic Systems at the Ohio State University
Authors: Rizzoni G. , Keyhani A. , Washington G. , Chandrasekaran B. , Baumgartner G. 
Published: January 2022

Abstract
The aim of the present paper is to describe an ongoing curriculum development effort in Mechatronic Systems education at the Ohio State University, in collaboration among the departments of electrical and mechanical engineering, and of computer and information sciences. The paper presents the motivation for such a development, the history of mechatronics education at OSU, the current structure of the curriculum, and plans for future development.
The Effect of Grinding Machine Stiffness on Surface Integrity of Silicon Nitride
Authors: Yang Fulun , Zhang Bi , Wang Jiexin , Zhu Zhenqi , Monahan Richard 
Published: January 2022

Abstract
A theoretical model based on mechanics and machine dynamics is presented to describe the effect of machine stiffness on surface integrity of ground silicon nitride. Experimental results are also presented to verify the model. The damage depth of ground workpieces is assessed against different machine stiffnesses. The modeling and experimental results demonstrate that there exists a critical machine stiffness in grinding of ceramics. When machine stiffness is higher than the critical stiffness, no chatter should occur in the grinding process. In this case, damage depth increases with the increase of machine stiffness under the single pass grinding process. In contrast, if machine stiffness is lower than the critical stiffness, chatter can occur in the grinding process that may induce grinding damage. The theoretical model can also be used to predict the critical machine stiffness for other types of structural ceramics.
Robust Nonlinear Control Based on Describing Function Methods
Authors: Taylor James H. 
Published: January 2022

Abstract
The robust control problem for nonlinear systems is discussed from the standpoint of the amplitude sensitivity of the nonlinear plant and final control system. Failure to recognize and accommodate this factor may give rise to nonlinear control systems that behave differently for small versus large input excitation, or perhaps exhibit limit cycles or instability. Sinusoidal-input describing functions (sidfs) are shown to be effective in dealing with amplitude sensitivity in two areas: modeling (providing plant models that achieve an excellent trade-off between conservatism and robustness) and nonlinear control synthesis. In addition, sidf-based modeling and synthesis approaches are broadly applicable. Several practical SIDF-based nonlinear compensator synthesis approaches are presented and illustrated via application to a position control problem.
Closed-Form Optimal Controllers for Nonlinear Uncertain Systems
Authors: Krstić Miroslav , Deng Hua 
Published: January 2022

Abstract
We review our recent results on stabilization and optimal disturbance attenuation for nonlinear systems with uncertainties. The systems are affine in the control and the disturbance but otherwise general. We treat both deterministic and stochastic disturbances. In both cases the disturbance attenuation problem is posed as a differential game (in the stochastic case the player opposed to control is not the noise itself but its covariance). The results are based on control Lyapunov function techniques. The full account of the results is given in our new monograph (Stabilization of Nonlinear Uncertain Systems, Springer, 1998).
Development of NDE Technology for Health Monitoring of Load-Support Systems of Superconducting Magnets for MAGLEV
Authors: Aoyama Hiroshi , Watanabe Hiroyuki , Terai Motoaki 
Published: January 2022

Abstract
Magnetically levitated vehicles (MAGLEVS) using superconducting magnets have been under development in Japan. One of the load-support systems for the superconducting magnet consisits of a biconical, alumina-fiber-reinforced-plastic (FRP) structure. Safe operation of the superconducting magnet will be jeopardized if the mechanical condition of the load-support system begins to degrade. One of the factors that influences the soundness of the superconducting magnet is the stiffness of the load-support system. Here, it is important to know the relation between the degradation in stiffness and the growth of defects. So we carried out the fatigue test of the load-support system. The various defects (matrix cracking and delamination of FRP laminates) were revealed during this fatigue testing. Two types of non-destructive-evaluation (NDE) methods (ultrasonic evaluation and transmitted light technique through FRP) were applied to monitor and assess the soundness of alumina/epoxy load-support systems.
An Assessment of the Textile Preform Technology for Structural Composites
Authors: Chou Tsu-Wei , Kamiya Ryuta , Cheeseman Bryan A. 
Published: January 2022

Abstract
By reviewing the design methodology of textile structural composites, the relationship between the various textile forming techniques and some basic structural elements under various loading configurations is detailed. Additionally, an analytical technique to predict the stiffnesses of the resulting textile composite is discussed and a comparison between the predicted and measured in-plane stiffnesses for three different textile architectures is reviewed. Finally, an examination is made of the Mode I fracture toughness characterization of a stitched textile composite.
A Note on Helmholtz Attenuators With Air Cavity and Membrane
Authors: Wang Xiaodong , Feng Zhigang 
Published: January 2022

Abstract
In this paper, we present an analytical expression for the resonance frequency of Helmholtz attenuators with air cavity and membrane. We derive the characteristic equations based on one-dimensional isentropic acoustic models and illustrate the effects on the resonance frequency of certain design variations.
Active Vibration Isolation of Plate Structures Using a Kalman Estimator-Based Feed-Forward Controller
Authors: El-Sinawi Ameen H. , Kashani Reza 
Published: January 2022

Abstract
Active isolation of plate structures subject to base excitation using a novel Kaiman estimator-based, feed-forward controller is studied. The controller is always 2nd order irrespective of the complexity of the structure being controlled. Moreover, it does not require real-time adaptation and yet stays effective when the attributes of the base excitation change. Using the proposed controller, the vibration attenuation of a plate (the size of a computer board) with two different boundary conditions are demonstrated.
On Enhancing Eutectic Solder Joint Reliability Using a 2nd-Reflow-Process Approach
Authors: Chiang Kuo-Ning , Cheng Hsien-Chie 
Published: January 2022

Abstract
A three-dimensional solder liquid formation model is developed for predicting the geometry, the restoring force and the reliability of solder joints in an area array type of interconnects (e.g., ball grid array (BGA), flip chip) under various pad configurations. In general, the restoring force and the reliability of the solder joints depend on the thermal-mechanical behaviors of the solder, the geometry configuration of the solder ball, and the geometry layout/material properties of the package. A good solder pad configuration could lead to a larger restoring force along the gravitational direction (a higher standoff height and a blunter contact angle) with a better reliability characteristic achieved. In this research, a 2nd-reflow-process approach is applied for the reliability enhancement of typical BGA assemblies, including PBGA and SuperBGA assemblies. The results show that the 2nd-reflow-process approach could significantly increase the fatigue life of the solder joint.
Numerical Study on the Axial Flow Force of a Spool Valve
Authors: Wang Linxiang , Chen Ying , Lu Yongxiang 
Published: January 2022

Abstract
This paper studied the fluid flow in a spool valve numerically using the k-ε two-equation model of turbulent flow, while experimental results were drawn out by means of particles image velocimetry technology. The numerical result is compared with the experimental one to verify the viability of the numerical method. Based on many times calculations, it is found that the spool valve’s steady axial flow force can be reduced considerably just by modifying the relative position of the oil ports and buckets.
Experimental Evaluation of Noise due to Flow Over Surface Steps
Authors: Farabee Theodore M. , Zoccola Paul J. 
Published: January 2022

Abstract
This paper presents results obtained from an experimental investigation of noise generated by the passage of a turbulent boundary layer over two generic surface irregularities: a forward-facing step and a backward-facing step. Acoustic measurements were made in a low-noise wind tunnel using a directional microphone system. The experimental arrangement used is similar to that used for earlier studies of the surface pressures upstream and downstream of steps. Two step heights were evaluated and data were acquired for two free-stream velocities. One important finding is that although noise from the backward-facing step could not be measured above background levels, noise from the forward-facing step was readily detected and broadband in nature. Noise from the forward-facing step is found to originate from the immediate vicinity of the step and scales on the seventh power of velocity. The results from this study also demonstrate the utility of a directional microphone for radiated noise measurements in a wind tunnel.
Broadband Noise From a Propeller in a Turbulent Flow
Authors: Manoha Eric 
Published: January 2022

Abstract
Marine propellers, operating al the aft end of vessels, interact with the turbulent boundary layer developed along the whole length of the hull. This interaction results in fluctuations of blade angle-of-attack, inducing lift fluctuations which are known to be sources of radiated broadband noise. The prediction of this noise requires the knowledge of turbulence features like velocity integral length scales or wavenumber-frequency spectra. The aim of the present experimental/numerical study is to complete such a broadband aeroacoustic prediction in the case of a propeller operating at the conical end of an axisymmetric body.
A formulation of the propeller broadband radiated noise was derived from the dipolar term of the Ffowcs Williams-Hawkings equation. It uses the free field, uniform subsonic flow, acoustic Green’s function developed on its angular modes. It also includes the lift fluctuations induced on the blade sections, which may be classically written using a 2D Sears function, the propeller design (pitch, chord, skew, rake), and the wavenumber-frequency spectrum of the velocity component normal to the blade section.
To address this velocity wavenumber-frequency spectrum, the body was mounted in the ONERA F2 windtunnel for turbulence characterization based on 2-point measurements using a cross hot-wire probe and a Laser Doppler Anemometer (LDA). This specific instrumentation provided cross-correlations for various spacings in the axial, radial and tangential directions, at several locations in the turbulent field ingested by the rotating propeller. These data were used to adjust an analytical model of the velocity cross-correlation and of the corresponding velocity wavenumber-frequency spectrum.
In the last step, the same body and propeller were tested in the ONERA CEPRA 19 anechoic wind tunnel for acoustic characterization. The measured noise spectra were compared to the spectra predicted using the above turbulence measurements and formulation applied to the CEPRA 19 experiment conditions. Measured and predicted spectra are in good qualitative agreement but predicted noise levels slightly overestimate the measured values.
Free Bending Vibrations of Composite Base Plates or Panels Reinforced by a Non-Central Stiffening Plate Strip
Authors: Yuceoglu U. , Özerciyes V. 
Published: January 2022

Abstract
The problem of the free bending vibrations of a composite base plate reinforced by a bonded, non-central stiffening plate strip is considered. The lower composite base plate and the upper non-central stiffening strip are assumed to be dissimilar orthotropic Mindlin plates joined by a very thin and flexible adhesive layer. The entire composite plate or panel system has two opposite edges as simply supported while the other two opposite edges may have arbitrary boundary conditions. The governing partial differential equations are first reduced to a special set of ordinary differential equations in the first order form and, then, they are integrated by the “Modified Version of the Transfer Matrix Method”. The mode shapes and the corresponding natural frequencies of the stiffened composite plate or panel system are obtained for “hard” and “soft” adhesive layer cases. The natural frequencies of the system for several boundary conditions and parameters are studied. It was found that the hardness and the softness of the adhesive layer significantly influence the mode shapes and the corresponding natural frequencies.
Theory of the Compression Wave Generated When a High-Speed Train Enters a Tunnel
Authors: Howe M. S. 
Published: January 2022

Abstract
A review is given of the theory of the compression wave generated when a high-speed train enters a tunnel. The train is modeled by a distribution of monopole sources whose interactions with the tunnel portal determine the detailed characteristics of the wave. The waveform can be calculated exactly at subsonic train Mach numbers for a tunnel consisting of an unflanged cylinder of semi-circular cross-section, which has been the subject of extensive experimental study. An analysis of this case reveals how an approximate theory can be developed for arbitrary tunnel portals and train Mach numbers as large as 0.4. Details are given for flanged portals of both semi-circular and rectangular cross-sections. Nonlinear steepening in a very long tunnel is responsible for an intense, environmentally harmful, micro-pressure wave, which propagates as a pulse from the distant tunnel exit when the compression wave arrives, with amplitude proportional to the maximum gradient in the compression wavefront. The analytical theory permits the design of tunnel portals that greatly increase the initial wave thickness (thereby tending to inhibit wave steepening), either by flaring the portal, or by installing a tunnel entrance hood, which allows high pressure air produced by the train to be vented to the environment through windows in the side walls. A formula is given for the ‘optimum’ flared portal, which produces a pressure gradient across the wavefront that is constant and an overall minimum, so that the pressure in the wavefront increases linearly and provides the maximal protection against shock formation. The operation of tunnel entrance hoods is discussed in terms of a continuum model in which an axial section of the tunnel extending inwards from the entrance is perforated with a distribution of small apertures.
Convective Heat Transfer and Flow Mixing in Converging-Diverging Channel Flows
Authors: Guzmán Amador M. , Amon Cristina H. 
Published: January 2022

Abstract
Mixing and heat transfer enhancement due to chaotic advection in a converging-diverging channel flow is characterized and quantified by spectral element direct numerical simulations of the time-dependent Navier-Stokes, continuity and energy equations. The computational simulations are performed in a two-dimensional converging-diverging channel model composed of sinusoidal walls. Results are presented for laminar and transitional flow regimes, in the Reynolds number range 110 &lt; Re &lt; 600.
Eulerian and Lagrangian flow characteristics, such as vortex dynamics and Lagrangian Lyapunov exponents, are evaluated to characterize the flow pattern and to determine the chaotic mixing as a function of the Reynolds number. Heat transfer parameters, such as the temporal evolution of the temperature distributions and Nusselt numbers, are obtained to determine the heat transfer performance. Lagrangian Lyapunov exponent evaluations indicate that the onset of chaotic mixing occurs at Re∼130, as the flow evolves from a laminar to a transitional state. Results reveal that the heat transfer enhancement is due to chaotic mixing of fluid particles whose Lagrangian trajectories diverge exponentially fast. It is also found that chaotic mixing is stronger m the vortical regions and spreads to other flow regions as the Reynolds number increases.
Channel Flow in Porous Media in the Limit as Porosity Approaches Unity
Authors: Travkin V. S. , Catton I. , Hu K. 
Published: January 2022

Abstract
A mathematical model that predicts turbulent flow and heat transfer for plane two-dimensional channel flow in a porous medium in the limit as porosity approaches unity is developed. The development is carried out in two steps. The first is based on partial differential equations for momentum and energy conservation in the fluid and solid phases (two temperatures) in the channel derived from volume averaging theory (VAT) for a medium with a continuously changing of porosity and specific surface area. The second is to make changes to the porous layer morphology on the surfaces of the channel. After constructing closure models for the above equations, the features of momentum in the channel are shown to smoothly converge to the transport characteristics of a plane channel.
Heat Transfer Education: Keeping it Relevant and Vibrant
Authors: Khounsary Ali M. , Mondt James R. , Simon Terry , Agonafer Dereje , DeWitt David P. , Figliola Richard S. , Grosshandler William L. , Kreith Frank 
Published: January 2022

Abstract
The motivation for a fresh look at heat transfer education, both in content and in methodology, is generated by a number of trends in engineering practice. These include the increasing demand for engineers with interdisciplinary skills, rapid integration of technology, emergence of computerized and interactive problem-solving tools, shortening time of concept-to-market, availability of new technologies, and an increasing number of new or redesigned products and processes in which heat transfer plays a part. Examination of heat transfer education in this context can be aided by considering the changes, both qualitatively and quantitatively, in the student, educator, and researcher populations, employment opportunities, in the needs of corporations, government, industry, and universities, and in the relevant technical problems and issues of the day.
Such an overview provides the necessary background for charting a response to the difficult question of how to maintain excellence and continuity in heat transfer education in the face of rapid, widespread, and complex changes. The present paper addresses how to make heat transfer education more relevant and stimulating. This paper represents a written summary of a 1996 panel discussion at the 1996 International Mechanical Engineering Conference and Exhibition (IMECE) of the American Society of Mechanical Engineers (ASME) in Atlanta, Georgia, on “Heat Transfer Education: Keeping it Relevant and Vibrant,” with significant expansion and amplification by the authors and the panelists in the 1997–98 period.
The consensus of the participants is that the steps necessary to ensure the desired outcome in heat transfer education should include: (1) a better understanding of the interaction between the student, course content, and market needs; (2) an appreciation of the need in multidisciplinary industrial environments for engineers trained with a broad background; (3) a revision of the introductory heat transfer course to incorporate illustrative and insightful industrial examples and case studies reducible to order-of-magnitude analyses; (4) a reinforcement of real-world problem-solving abilities in students by introducing them to examples that emphasize multidisciplinary issues in modern thermal management problems; and finally (5) industrial collaboration that would provide the educator with meaningful thermal management case studies (and possible funding), the student with an appreciation of industrial practices, and the industrial sponsor with access to academia for assistance in problem solving. Also suggested is an effective regular review program to provide assessment, feedback, and suggestions for quality control to interested institutions on their teaching methodology and materials.
Micro Channel Heat Exchanger for Cooling Electrical Equipment
Authors: Kawano Koichiro , Minakami Ko , Iwasaki Hideo , Ishizuka Masaru 
Published: January 2022

Abstract
The micro channel heat exchanger, which has many small channels (10–100 μm order), is a promising device to cool an integrated circuit, which generates a large amount of heat. In order to investigate the performance of the micro channel heat exchanger, three-dimensional numerical simulations and experiments on heat transfer behavior and pressure loss were carried out. So far as the heat transfer phenomena is concerned, results obtained using a silicon tip micro channel model a very small thermal resistance, about 0.1(K cm2/W) at Re = 300. And, in the designing of heat exchanger, the pressure loss phenomenon is of practical importance. In the present study, measured pressure loss was good agreement with that of analytical result obtained on the basis of fully developed laminar pipe flow assumption.
Furthermore, a practical setup was made with a micro channel heat exchanger to clarify the possibility of using the micro channel heat exchanger in electrical equipment. As a result, it was confirmed that the performance of the micro channel heat exchanger system is sufficient to cool a silicon chip which generates a large amount of heat, and the scale of the system is compact compared to that of the whole setup of electrical equipment.
Heat Transfer in Generator Armature Bar Region Near a Resistance Temperature Detector
Authors: Tong Wei 
Published: January 2022

Abstract
This paper presents a simplified heat transfer analysis of the generator armature bar region near a resistance temperature detector (RTD). During generator operations, heat is generated in the generator due to the various losses. With conventional indirect cooling, heat is removed from copper conductors to the steel core through the conductor insulation. It is desired to minimize the thermal resistance to achieve the highest heat transfer rate.
Heat transfer characteristics in the generator armature bar region were obtained using an FEM model. Results show that the RTD temperature is primarily determined by the boundary temperatures on the copper conductor and silicon-iron walls, and thermal conductivity of RTD and armature bar insulations. Sensitivity studies have been performed to help engineers to optimize generator designs.