bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement for Frequency Domain Based Tool Breakage Detection System
Authors: Hamidieh Youssef A. , Seth Brij B. , Sridhara Raghunandan 
Published: November 2021

Abstract
Effective monitoring of machining operations, for tool breakage and wear in automotive powertrain manufacturing, has proven difficult despite significant activity in industry and universities. Various monitoring schemes have been tried with different sensing strategies and algorithms. Despite these efforts, results have been mixed, with systems working in some operations and not in others or systems requiring too much attention on the plant floor. All this, while the need for reliable monitors, due to emphasis on productivity and quality, continues to increase. Some of the reasons for the limited success of monitoring systems include changing machine condition, variability of cutting edge on tools due to regrind, the variability of incoming part material together with different possible failure modes for the tools. The shortcoming of existing monitoring systems has been even more apparent in multi-spindle and spindle cluster stations whereby a number of tools operate simultaneously, therefore adding to the complexity. The frequency and time domain vibration1 based monitoring strategy described in this paper for breakage detection addresses some of the shortcomings of the available systems by concentrating on discriminants which produce high signal to noise ratio. Also, by recognizing that the tool failure signatures may vary on different machines while performing the same machining operations with similar tools. This can be attributed to different structural characteristics of the spindles and other elements of the machine tools. Therefore, in this paper for the first time, a pre-characterization2 scheme is proposed to capture this vital information and to utilize it for adding further robustness to tool monitoring.
On Axisymmetric Vibration of Annular Plate of Parabolic Thickness Variation by Factorization of Differential Equation
Authors: Caruntu Dumitru I. 
Published: November 2021

Abstract
In the present paper an analytic solution of free axisymmetric vibration of a class of annular plates of parabolic thickness variation is obtained by factorization of the fourth-order differential equation. Poisson’s ratio is taken v = 1/3, applicable to many materials.
Inverse Dynamics of a Planar Flexible-Link Manipulator With Revolute-Prismatic Joints
Authors: Farid M. , Salimi I. 
Published: November 2021

Abstract
This paper proposes an inverse dynamic approach to determie the required actuating torque and force for a planar flexible-link manipulator with revolute-prismatic joints such that its end-point follows a given trajectory. The formulation includes all of the non-linear terms due to large rotation of the links. Since one of the joints is prismatic, the resulting system of equations is time varying too. The results show that by applying actuating loads found by the proposed algorithm, the tracking error becomes smaller than that resulting from actuating loads obtained based on rigid link modeling.
A Solution for the Interior Sound Field With a Nonuniform Temperature Distribution in the Vehicle Passenger Room
Authors: Wu Jiuhui , Chen Hualing 
Published: November 2021

Abstract
A non-linear wave equation in a nonuniform sound space is deduced to determine the coupling relation between sound field and temperature field. Adopting Poisson’s integral a formula for calculating the interior sound field with uneven temperature field and certain initial conditions is developed. This establishes the corresponding theoretical foundation for studying the heat and vibroacoustic comfortability in a vehicle passenger room.
The Vibration Control of a Flexible Linkage Mechanism With Impact
Authors: Jin Chunmei , Qiu Yang , Fan Ling 
Published: November 2021

Abstract
An combined control methodology for suppressing elastic vibration and impact effects in clearance pairs are developed by employing active control of structural vibration and passive control concepts of clearance pairs in the structures. Numerical simulation is performed to evaluate the combined control effect of elastic vibration and impact effects. The analytical results indicate that the elastodynamic response in the mechanism with clearance connections can not be well controlled by using a single control method. Only through using combined control method the elastodynamic response can be controlled favorably and so the feasibility of combined control method is proved.
Dynamic Analysis of a Slider-Crank Mechanism With Flexible Connecting Rod and Viscous Friction
Authors: Zhang Jinfu , Xu Qingyu , Zhang Ling 
Published: November 2021

Abstract
The equation of motion for the slider-crank mechanism with flexible connecting rod and viscous friction are formulated using Lagrange equation. Viscous friction and coupling effect between rigid body motion and elastic deformation are considered in the formulation. Numerical results show that viscous friction and flexibility of connecting rod have effects on motion of the mechanism.
Reliable Subjective Assessment of Vehicle Handling by Drivers: Is it an Elusive Goal?
Authors: Crolla D. A. , Whitehead J. P. 
Published: November 2021

Abstract
Much progress has been made over recent years in understanding many aspects of driver-vehicle interactions, for example, linked to ergonomics/comfort of the cabin, influence of improved safety systems, interactions with ITS systems etc. However, in more dynamic situations, similar levels of understanding have not been achieved. Such dynamic events range from whole body motions such as vehicle handling and ride to component behaviour including, in particular, steering wheel feel and gearshift quality.
Nonlinear Active Rollover Prevention Control Strategies for a 5-Axle Tractor/Semitrailer
Authors: Lewis A. Scott , El-Gindy Moustafa 
Published: November 2021

Abstract
This paper presents new active control strategies to prevent heavy vehicle rollover and focuses mainly on cases of maneuver-induced rollover such as rollover in cornering and lane-change maneuvers. Two performance measures as control strategies are explored: the lateral load transfer ratio and the trailer lateral acceleration. A nonlinear 75,000 pound 5-axle tractor/semitrailer computer simulation model has been used to demonstrate the effectiveness of the proposed active control system. A new non-linear sliding mode controller has been designed and found to be effective in improving the dynamic performance and roll stability, regardless of parameter uncertainties, such as tires or suspension characteristics. The controller torque requirement is limited by the differential dynamic braking forces that the tractor drive axles are able to produce as a function of the applied dynamic loads and road surface condition. The results show that with this new controller, the vehicle lateral acceleration can be controlled to prevent rollover without significant change of the vehicle trajectory when active yaw torque is applied to the tractor drive axles. Also, simulation results indicate that the vehicle rollover might be prevented using either the lateral load transfer ratio or the lateral acceleration at the trailer centre of gravity as control strategies.
The Use of Modeling and Simulation in Ground Vehicle Analysis
Authors: Letherwood Michael D. , Gunter David D. 
Published: November 2021

Abstract
In support of Department of Defense (DOD) mandated acquisition reform initiatives to reduce vehicle related life cycle costs and timelines, the Tank-automotive and Armaments Research, Development and Engineering Center (TARDEC) is using simulation-based acquisition strategies to investigate the dynamic performance of wheeled and tracked ground vehicles. These strategies are used throughout the vehicle development, testing, and fielding life cycle process. The paper will describe how modeling and simulation (M&S) is applied to answer a wide variety of design and performance evaluation questions. It will also depict a series of simulation-based engineering projects that build on the Army’s simulation investments as a tool to investigate and answer real-world vehicle design, acquisition, and engineering support questions.
Utilising the Potential of Individual Wheel Control on a 6x6 Off-Road Vehicle
Authors: Jackson Andrew , Brown Michael , Crolla David , Woodhouse Adrian , Parsons Michael 
Published: November 2021

Abstract
This paper will present a form of mobility control for a 6x6 Hybrid Electric Vehicle (HEV). The vehicle concerned is a series configured HEV utilising Hub Mounted Electric Drives (HMED) at each of the six wheel stations to provide Individual Wheel Control (IWC). Whereas a conventional vehicle needs individual brake actuators or bulky differentials to vary individual wheel torques, IWC can be realised in this hybrid configuration through software control of each HMED, making it potentially more accurate, responsive and flexible than a mechanically implemented version.
Direct Yaw-moment Control (DYC) is a method of regulating individual wheel torque to control vehicle yaw motion, providing greater stability in cornering. By varying the torque applied to the left and right wheels, tyre forces can be controlled to produce a desired yaw moment. Not only can this be used to aid cornering, but also to reject disturbances, such as side winds, in straight line running. When combined with a Traction Control System (TCS), optimisation of these tyre forces are considered, ensuring that the vehicle handling characteristics remain stable while acceleration performance is improved. When integrating these two systems, consideration is given to the torque demands of each controller. This co-ordinated control ensures that the vehicle takes full advantage of the torque capabilities associated with the electric motor to provide improved vehicle handling, acceleration and stability.
The proposed control algorithms are implemented in MATLAB/SIMULINK on a basic non-linear vehicle handling model utilising a Dugoff tyre model to determine longitudinal and lateral tyre forces. The torque of each individual wheel is controlled to maintain a desired yaw rate and/or wheel slip. The model is then simulated on a number of road surfaces, undertaking a variety of test manoeuvres to assess the potential improvements that the combined controller can offer over a vehicle with fixed-torque distribution. The paper shows how the resultant controller offers a robust method of improving vehicle mobility, providing good stability under varying conditions.
Numerical Simulations of Resonant Heat Transfer Augmentation at Low Reynolds Numbers
Authors: Greiner Miles , Fischer Paul F. , Tufo Henry 
Published: November 2021

Abstract
The effect of flow rate modulation on low Reynolds number heat transfer enhancement in a transversely grooved passage was numerically simulated using a two-dimensional spectral element technique. Simulations were performed at subcritical Reynolds numbers of Rem = 133 and 267, with 20% and 40% flow rate oscillations. The net pumping power required to modulate the flow was minimized as the forcing frequency approached the predicted natural frequency. However, mixing and heat transfer levels both increased as the natural frequency was approached. Oscillatory forcing in a grooved passage requires two orders of magnitude less pumping power than flat passage systems for the same heat transfer level. Hydrodynamic resonance appears to be an effective method of increasing heat transfer in low Reynolds number systems where pumping power is at a premium, such as micro heat transfer applications.
On Low-Dimensional Galerkin Modeling of Confined Twin-Jet Flow and Heat Transfer
Authors: Gunes H. , Gocmen K. , Kavurmacioglu L. 
Published: November 2021

Abstract
The two-dimensional incompressible non-isothermal confined twin-jet flow has been numerically studied in the transitional flow regime by a finite volume technique. Results have been obtained for the velocity and temperature distributions close to the onset of temporal oscillations. Next, the proper orthogonal decomposition (POD) is applied to the instantaneous flow and temperature data to obtain POD-based basis functions for both velocity and temperature fields. These basis functions are capable to identify the coherent structures in the velocity and temperature fields. The low-dimensional Galerkin models of the full Navier-Stokes and energy equations are constructed by the Galerkin projection onto basis functions. Since the low-dimensional Galerkin models are much easier to analyze than the full governing equations, basic insights into important mechanisms of dynamically complex flow and heat transfer (e.g. flow instabilities) can be easily studied by these models. The numerical implications, the validity of the models and their performance characteristics are discussed.
Experimental Flow Field and Heat Transfer Study of a Slot Jet Reattaching Onto a Flat Plate
Authors: Narayanan V. , Seyed-Yagoobi J. , Page R. H. 
Published: November 2021

Abstract
Detailed heat transfer, impingement surface pressure and flow field measurements on a submerged slot jet reattachment nozzle are presented. The nozzle is comprised of a rectangular region of aspect ratio 20:1, with circular ends. The jet exits the nozzle parallel to an adjacent flat impingement surface and reattaches onto it. Contours of local heat transfer exhibit three-dimensionality within the recirculation and reattachment regions with increase in nozzle-to-surface spacing. Mean and time averaged fluctuating surface pressure distribution at the center plane of the nozzle along the minor indicate that the location of peak fluctuating pressure occurs upstream of the peak mean pressure. Flow field measurements are presented for a nozzle-to-surface spacing of 3.85 exit hydraulic diameters from the surface, at a turbulent exit Reynolds number of 10 500. Surface pressure and flow field observations are used to explain heat transfer results in the recirculation and reattachment regions.
Fundamental Heat Transfer Correlations for Natural Convection From a Uniformly Heated Vertical Plate
Authors: Aydın Orhan , Guessous Laila 
Published: November 2021

Abstract
The problem of natural convection from a uniformly heated vertical plate has long been investigated due to its relevance to many industrial applications. Attempts have been made over the years to develop generalized heat transfer correlations that would cover a large range of Prandtl numbers. Here we introduce, on fundamental grounds, a new dimensionless parameter for the correlation of natural convection induced by a vertical plate subject to a constant wall heat flux. This dimensionless parameter, which depends on the Prandtl number, Pr, and the modified Rayleigh number, Ra*, is used to correlate the heat transfer over the entire Prandtl number domain. The development is based on physical and dimensional arguments and leads to correlations relating the laminar Nusselt number to the new parameter. Comparison with published empirical, numerical, and theoretical results leads to excellent agreement over the Prandtl number domain studied, which spans the range between 0.001 and 1000.
Particle Image Velocimetry Measurements of Confined Co-Rotating Vortices in a Square Duct
Authors: Langford Heather M. , Beasley Donald E. 
Published: November 2021

Abstract
The axial development of a paired co-rotating vortex system is experimentally studied in a square duct. The duct confines the vortex system. The co-rotating vortices are shed from a pair of NACA 0012 airfoils in a split-wing configuration. Lateral velocity fields are measured using particle image velocimetry. Time-averaged lateral velocity and axial vorticity fields are used to document the location of the vortices in the lateral flow field. The present study examines the effect of Reynolds number, lateral spacing, and angle attack on the development of the vortex system in a confined geometry.
Single-Phase Turbulent Rod Bundle Heat Transfer
Authors: Armfield Mary V. , Langford Heather M. , Beasley Donald E. , Conner Michael E. 
Published: November 2021

Abstract
The present study investigates single-phase heat transfer coefficients in a 5 × 5 horizontal rod bundle representing a water-cooled nuclear reactor. The rod bundle assembly consists of a square array of parallel rods held in place by support grids. Flow-enhancing features such as disc blockage or split-vane pairs are often added to the downstream edge of the support grids in an attempt to improve the heat transfer performance of the rod bundle assembly. The effects on the local heat transfer coefficients of several support grid designs are examined in the present study.
The local, average heat transfer coefficients are measured using a heated copper sensor for standard, disc, and split-vane pair grid designs. In addition, lateral flow fields are obtained for the split-vane pair grid design using Particle Image Velocimetry (PIV) measurements. Results indicate that the local heat transfer coefficient is enhanced just downstream of the support grids. This enhancement decays to the fully-developed value of heat transfer by five hydraulic diameters downstream of the support grid for all of the grid designs. Heat transfer measurements of the split-vane pair grid design indicate a region of decreased heat transfer below the fully-developed value. Identification of swirl migration and weak exchange of fluid between subchannels in the lateral flow fields of the split-vane pair grid design provides insight into the decreased region of heat transfer.
Numerical Simulations and Experimental Investigations of the Flow Field and Heat Transfer of Fin-and-Tube Heat Exchangers
Authors: Bender Jens K. , Schmidt Roland K. , Koehler Juergen 
Published: November 2021

Abstract
The investigation of the flow field and heat transfer of fin-and-tube heat exchangers is presented. The numerical simulation is focused on the heat transfer, whereas the emphasis of the experimental investigation is put on the flow field.
The numerical calculations are carried out with the CFD-Code “Fluent”. The highly complex geometry of the heat exchanger is modelled by CAD, covered by a hybrid mesh, and simulated using finite-volume-technique. The results of the overall pressure drop and heat transfer are compared with measurements made by the authors as well as with other experimental data available in the literature.
For the experimental set-up a heat exchanger model was designed using perspex that allows measurements with PIV technique. The investigations concentrate on the influence of different geometries (tube diameters, tube distances, etc.).
A Numerical Study of the Effect of Subcooling on Natural Convection in a Densified Cryogenic Propellant
Authors: Akyuzlu K. M. , Antoniou A. , Manalo L. , Nguyen K. 
Published: November 2021

Abstract
A numerical study is conducted to investigate the effect of subcooling on natural convection in a densified cryogenic propellant. It is assumed that the cryogenic propellant (liquid oxygen in this study) is subcooled through a densification unit and then stored in a cryogenic tank which is pressurized with helium. Natural circulation in the propellant is initiated by the heat leak through the walls of the cryogenic tank that sets up a thermal stratification in the liquid with time. A two dimensional (radial and axial) single domain (liquid) mathematical model is adopted to investigate this transient phenomenon. The physics based mathematical model consists of conservation of mass, momentum, and energy equations for the liquid subjected to prescribed temperature (saturation temperature for the ullage pressure) at the vapor-liquid interface and constant wall heat flux boundary condition at the walls of the container. The density of the propellant is assumed to be temperature dependent only in the buoyancy term of the momentum equation (Boussinesq approximation.) The transport properties of the fluid are assumed temperature dependent in all of the equations. The resulting nonlinear governing equations are solved by an explicit finite-difference technique to predict the transient velocity and temperature fields inside the propellant. Finally, numerical simulations are carried out to study the effect of subcooling on thermal stratification using the proposed model.
A Numerical Study of the Development of Unsteady Three-Dimensional Natural Convective Flow in a Horizontal Enclosure With a Uniform Heat Flux on the Lower Surface
Authors: Oosthuizen Patrick H. 
Published: November 2021

Abstract
Flow in a rectangular enclosure with a square horizontal cross-section and with a uniform heat flux applied across the lower horizontal surface and with the upper horizontal surface cooled to a uniform low temperature has been considered. The vertical side-walls of the enclosure are adiabatic. It has been assumed that the flow is laminar and that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces. In this situation, there is no flow in the enclosure at low Rayleigh numbers, steady flow in the enclosure at intermediate Rayleigh numbers and an unsteady flow in the enclosure at high Rayleigh numbers. The conditions under which unsteady flow develops have been numerically investigated in the present study. The unsteady form of the governing equations, written in terms of the vector potential and vorticity vector functions and expressed in dimensionless form, have been solved using a finite-difference procedure. The solution was started with no flow in the enclosure. The solution, in general, has the following parameters: the heat flux Rayleigh number Raq, the Prandtl number and the aspect ratio A of the enclosure, i.e. the ratio size of the height of the enclosure to the size of the square cross-sectional shape of the enclosure. Results have only been obtained for a Prandtl number of 0.7. Results for values of A between 1.25 and 3 for various values of Rayleigh number (up to 80000) have been obtained. The results have been used to determine the effect of A on the value of Rayleigh number above which there is unsteady fluid motion in the enclosure.
Stochastic Modelling of Scalar Transport in Turbulent Flows Based on Conditional Moment Closure
Authors: Klimenko A. Y. , Wandel Andrew P. , Smith Nigel S. A. 
Published: November 2021

Abstract
The difficulties of modelling transport of scalar properties (such as temperature and concentrations) in physical space are well-known. It is conventional to call the turbulent scalar transport as turbulent diffusion. However, if a strict mathematical definition of the term “diffusion” is to be used, this stochastic process is not a diffusion process since its characteristic time is quite long. That is why the gradient-based approximations of the turbulent fluxes, which are precise for the diffusion transport, may have some difficulties when dealing with a turbulent flow. In the present work, we investigated an alternative formulation of the turbulent scalar transport: the transport of one scalar with respect to another scalar. Using DNS data, we demonstrated that this transport can be much better approximated by a diffusion process than the turbulent scalar transport in physical space. This property is effectively used in Conditional Moment Closure (CMC) which deals with turbulent transport of reactive scalers (i.e. scalars participating in chemical reactions) with respect to the conserved scalar.
The similarity with diffusion processes can be used to numerically simulate this process by stochastic differential equations. Although solving such equations would be much easier than using DNS to predict characteristics of the turbulent scalar transport, the idea needs a proper theoretical analysis due to the complicated structure of CMC equations which have, in their conserved form, both forward and inverse parabolic terms. In the present work, we also demonstrated how the CMC equations can be properly represented by a stochastic model.