bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of an Oblique Collision of a Locomotive and an Intermodal Container
Authors: Tyrell David C. , Severson Kristine J. , Marquis Brian P. , Perlman A. Benjamin 
Published: December 2021

Abstract
This paper presents an approach to modeling an oblique collision of a locomotive and an intermodal container. Previous studies of offset and oblique train collisions have used one and two-dimensional models to determine the trajectories of the equipment during the collision (Mayville, et al. 1995, Tyrell, et al, 1997). This analysis uses a three-dimensional model to determine the trajectories of the equipment.
In the collision scenario of concern, an intermodal container impacts the outboard corner of the short hood of a wide-nose locomotive above the deck. An impact element has been used in the collision dynamics model to transfer contact load to the short hood of the locomotive. A detailed non-linear finite element model has been developed to characterize the force-crush behavior of the short hood. These results determine the parameters that connect the impact element to three-dimensional lumped-masses that represent vehicles in the consist. The collision dynamics analysis includes the influence of the locomotive suspension and the trailing locomotive.
The model has been used to evaluate the influence of short hood design on intrusion into the operator’s cab, the deceleration of the locomotive during the collision, and whether derailment of the locomotive occurs as a consequence of the collision. Results indicate that short hood strength can be increased significantly above the strength of the current design without derailing the locomotive in this collision scenario. More short hood strength increases the maximum closing speed that can be sustained without intrusion into the operator’s cab, while the deceleration of the operator’s cab remains relatively low.
A Semi-Empirical Method for Estimating the Effective Leak and Vent Areas of an Airbag
Authors: Anagonye Aloysius U. , Wang J. T. 
Published: December 2021

Abstract
A semi-empirical method that utilizes tests from a small fabric specimen to quantify the effective leak and vent areas of an entire airbag is developed in this paper. The test setup and procedure used in the airbag material coupon tests are similar to the standard method used in determining air permeability of fabrics. A test apparatus for measuring the deflection of the fabric coupon was devised. Finite element analysis is used to compute the expanded vent and airbag surface areas of the coupon under various deformations. The leak and vent models were developed based on the results of a regression analysis. The effective vent area of a fabric coupon is a function of the ratio of the pressures across the fabric and the expanded vent area. Similarly, the effective leak area of a fabric coupon is a function of the ratio of the pressures across the fabric and the expanded surface area. The tested airbag materials were characterized with these models for use with finite element airbag models.
The Relationship of Driver Airbag Design Parameters to an Out-of-Position Small Female Thorax Injury
Authors: Mu William , Sheng Jianping , Chen Chao 
Published: December 2021

Abstract
Airbag related out-of-position occupant (OOPO) thorax injury was investigated for many years. However, little study was published to address how to reduce the OOPO related thorax injury from the point of view of restraint system design. The objective of this investigation is to utilize both experiment and computer simulation approaches to study the OOP small female thorax injury mechanism and its relationship to the restraint system design parameters. Coupled structure, computational fluid dynamics (CFD) and rigid multi-body dynamics simulations were performed to investigate the effect of airbag deployment on OOPO thorax injury. The laboratory experiments are performed to validate the simulation results. Then the relationship of airbag design parameters on OOPO thoracic injury risk is characterized. The outcomes of this study lay down the foundations for advanced restraint system development.
The Effects of Common Misuses of a Child Safety Seat in an Automobile Crash
Authors: Canha Joseph , Greif Robert , Neat George 
Published: December 2021

Abstract
This paper investigates the effects the four most common misuses of a child safety seat (CSS) have on a toddler involved in a motor vehicle crash using a validated MADYMO model. These misuses involved a locking clip, shoulder harness chest clip and straps, and vehicle safety belt. A properly seated toddler in a forward-facing CSS was secured to a standard vehicle seat in a 48-kph frontal collision. The new proposed injury criteria (HIC, chest acceleration, and maximum axial neck load) and other occupant responses were used for model evaluation. For a CSS with as little as 3 centimeters of excessive slack in the vehicle safety belt, the child dummy exceeds each of the injury threshold values. Although some misuses provide a significant increase in injury response, the other misuses either individually or combined did not increase the injury potential of the child dummy in this CSS to unacceptable levels.
A Constriction Resistance Model in Thermal Analysis of Solder Ball Joints in Ball Grid Array Packages
Authors: Ying T. M. , Toh K. C. 
Published: December 2021

Abstract
The constriction resistance model is employed for the thermal analysis at the solder ball joint of a Ball Grid Array (BGA) package. The behavior of heat dissipation in solder joint is also analyst through Finite Element Modeling (FEM) and compared with the analytical model. The principle of constriction and spreading resistances is analyzed in detail because of the geometrical complexity encountered in BGA solder joints. The total resistance across the solder joint includes the internal resistance and external resistance. The internal resistance, which is the main focus of the analysis, consists of material resistance and constriction resistance. It is a function of material conductivity, thermal boundary conditions and geometric parameters. FEM solutions are in good agreement with analytical results of thermal resistance for single solder ball joint and multiple solder ball joints. The analytical resistance provides an accurate prediction on the temperature drop across the array of solder balls and hence the overall performance of the BGA packages. The pitch size is the main parameter in the investigation to study the heat dissipation of solder ball joints.
Inverse Heat Source Design Combining Radiation and Conduction Heat Transfer
Authors: França Francis H. R. , Ezekoye Ofodike A. , Howell John R. 
Published: December 2021

Abstract
This work investigates solutions of inverse heat source problems for combined-mode radiation and conduction. The problem consists of finding the heat source distribution in an absorbing-emitting medium that satisfies both the temperature and the heat flux distributions prescribed on the surfaces of a two-dimensional rectangular enclosure. The participating medium is gray, the walls are gray emitters and absorbers, and all the thermal properties are uniform. The combined heat transfer mode problem is described by a system of non-linear equations, which is solved by an iterative procedure. At each iteration a system of linear equations is solved, but, as often occurs in inverse problem, the system of equations is ill-conditioned, and the number of equations and the number of unknowns are not necessarily the same. The solution is obtained by regularizing the system by truncated singular value decomposition (TSVD). It is also discussed how to impose additional conditions to satisfy physical constraints that govern the heat source itself.
Investigation of Conjugate Heat Transfer in Interim Storage of High Level Radioactive Waste
Authors: Sizgek G. Devlet 
Published: December 2021

Abstract
Solidified high level radioactive wastes generate decay heat that must be taken into account during interim storage in engineered facilities prior to geological disposal. The continual heat generation within the canisters necessitates reliable heat removal to avoid overheating of the stored material and the surrounding safety barriers. This paper is concerned with the modelling and computation of heat transfer in one of the storage cells, based on the conceptual design study for natural convection cooled high level radioactive waste storage. All internal features of the storage cell have been explicitly modelled to analyse the internal heat transfer process by conduction and natural convection coupled with thermal radiation. One of the major objectives of the current study was to assess the contribution of radiation heat transfer in altering temperature profiles in the storage cell. Furthermore the model has been used to predict the effects of surface radiative properties, canister filling material conductivities and waste loading on the temperature and velocity fields. A variation in the enclosed air gap width and also cooling air channel width has also been performed to see their potential effect on temperature profiles of the storage cell.
Natural Convection Heat Transfer in a Vertical Square Duct With Radiation Effects
Authors: Yan Wei-Mon , Lee Kuan-Tzong 
Published: December 2021

Abstract
The present work investigates numerically the natural convection heat transfer with radiation effects in an open vertical square duct. The integro-differential radiative transfer equation is solved by discrete ordinates method. The vorticity-velocity formulation is applied to solve for the coupled momentum and energy equations. The effects of five major parameters, Grashof number Gr, conduction-to-radiation parameter Nc, optical thickness τ, single scattering albedo ω and temperature ratio Tr, on the combined natural and radiation heat transfer are discussed in detail. The numerical results of the dimensionless induced volume flow rate and average Nusselt numbers show that the thermal radiation would enhance the heat transfer rate. Additionally, the variations of the induced volume flow rate and total Nusselt number are independent of radiative parameters under fully-developed flow limit.
The Application of a Hue-Based Liquid Crystal Technique to Determine Convective Heat Transfer Downstream of Non-Axisymmetric Circular-to-Square Expansions
Authors: Guile Anthony W. , Garwood Roy , Ward John 
Published: December 2021

Abstract
A liquid crystal technique has been applied to the problem of convective heat transfer downstream of a circular to square abrupt expansion. This configuration is similar to that found with a burner firing into a furnace or boiler. There is little data available in the literature for these expansions as most previous investigations have concentrated on a simple circular to circular geometry.
Liquid crystals were selected for the tests because of their ability to provide a full surface temperature map with a high spatial resolution. With the progress of image capture and processing technology a transient test method was preferred as it makes the construction of models very simple by eliminating the need to heat the surface with the inherent problem of uniformity and the difficulty in viewing the surface.
The application of liquid crystals produced results which were found to be accurate and repeatable, when compared with results obtained from other investigations in the area. It gave quantitative data, allowing spanwise and axial distributions of heat transfer to be calculated in these geometries.
The hue capturing technique thus provides quantitative, accurate and repeatable temperature measurements, and when applied to heat transfer problems is a powerful experimental tool.
Heat Transfer Enhancement by Imposed Pulsation in a Channel With Sudden Expansion
Authors: Tandogan E. , Mitra N. K. 
Published: December 2021

Abstract
A numerical investigation of laminar pulsating flows in a channel with sudden expansion in the cross section has been performed by solving two dimensional Navier-Stokes and energy equations for an incompressible fluid. A sinusoidal pulsation has been imposed on the axial velocity at the inlet. Results show that the flow field symmetry at the channel axis vanishes at even a Reynolds number of 100. The time averaged Nusselt number of pulsating flow increases sharply over the nonpulsating flow in the Reynolds number range of 400 and 500. The time averaged Nusselt number on the two walls can be different.
Turbulent Boundary Layer Subjected to a Sudden Change in Surface Roughness and Temperature
Authors: Guimarães João Henrique D. , dos Santos Sergio J. F. , Su Jian , Silva Freire Atila P. 
Published: December 2021

Abstract
In present work, the dynamic and thermal behaviour of flows that develop over surfaces that simultaneously present a sudden change in surface roughness and temperature are discussed. In particular, the work is concerned with the physical validation of a newly proposed formulation for the near wall temperature profile. The theory uses the concept of the displacement in origin, together with some asymptotic arguments, to propose a new expression for the logarithmic region of the turbulent boundary layer. The new expressions are, therefore, of universal applicability, being independent of the type of rough surface considered. The present formulation may be used to give wall boundary conditions for two-equation differential models. The theoretical results are validated with experimental data obtained for flows that develop over flat surfaces with sudden changes in surface roughness and in temperature conditions. Measurements of mean velocity and of mean temperature are presented. A reduction of the data provides an estimate of the skin-friction coefficient, the Stanton number, the displacement in origin for both the velocity and the temperature profiles, and the thickness of the internal layers for the velocity and temperature profiles. The skin-friction co-efficient was calculated based on the chart method of Perry and Joubert (J.F.M., 17, 193–211, 1963) and on a balance of the integral momentum equation. The same chart method was used for the evaluation of the Stanton number and the displacement in origin.
A Numerical Study of Three-Dimensional Natural Convection in a Low Aspect Ratio Horizontal Enclosure With a Uniform Heat Flux on the Lower Surface
Authors: Oosthuizen Patrick H. 
Published: December 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 numerically studied. 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. 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 based on the equations. 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 size A of the square cross-sectional shape compared to the height of the enclosure. Results have only been obtained for a Prandtl number of 0.7. Results for values of A between 0.5 and 3 for various relatively low and moderate values of Rayleigh number (up to 40000) have been obtained. The results have been used to determine the effect of A on the value of Raq below which there is no fluid motion in the enclosure and to examine the various flow patterns that arise as the value of Raq is increased with various values of A. The effect of A on the variation of the mean dimensionless lower surface temperature with Ra has also been examined.
Natural Convection to Power-Law Fluids From a Heated Vertical Plate Under Mixed Thermal Boundary Conditions
Authors: Büyük Elif , Ece Mehmet C. 
Published: December 2021

Abstract
Steady free convection laminar boundary-layer flow subject to mixed thermal boundary conditions along a heated vertical plate immersed in a quiescent power-law fluid is investigated. Similarity solutions are obtained numerically for the boundary-layer velocity and temperature profiles. The effects of flow behavior index and the generalized Prandtl number on the surface shear stress and heat flux are determined.
Retrieval of Multidimensional Heat Transfer Coefficient Distributions Using an Inverse BEM-Based Regularized Algorithm: Numerical and Experimental Results
Authors: Divo Eduardo , Kassab Alain J. , Kapat Jay S. , Chyu Ming-King 
Published: December 2021

Abstract
Surface maps of heat transfer coefficients (h) are often determined by transient liquid crystal or other similar transient experimental techniques. This involves (1) conducting an experiment with an impulsively imposed convective boundary condition on an initially isothermal test object, (2) measuring the resulting time-dependent surface temperature distributions, and (3) solving the one-dimensional transient heat conduction equation for different points on the convective surface. There are many practical cases where this approach fails to adequately model the temperature field and, consequently, leads to erroneous h values. In this paper, we present an inverse boundary element method (BEM)-based approach for the retrieval of spatially varying h distributions from surface temperature measurements. In this method, an efficient numerical algorithm requiring only a surface mesh is used to solve the conduction problem. At each time level, a regularized functional is minimized to estimate the time-dependent heat flux and simultaneously minimize the effect of experimental measurement uncertainties in surface temperature values on the calculated heat flux. Newton’s cooling law is then invoked to compute h. Results are presented from several numerical simulations and from a laboratory experiment. The method is applicable to unsteady as well as to steady-state convective systems.
Dynamics of Heat Transfer in the Melt Pool at Nuclear Severe Accident Conditions
Authors: Horvat Andrej , Kljenak Ivo , Marn Jure 
Published: December 2021

Abstract
Prediction of thermal loads on nuclear reactor vessel lower plenum after core melting and relocation during a severe accident requires knowledge about the core melt behavior, especially the circulation pattern. To analyze the heat transfer dynamics on the lower plenum walls, two-dimensional numerical simulations of a fluid flow with internal heat generation were performed for Rayleigh numbers 106, 107, 108, 109, 1011 and 1013 at Prandtl number 0.8. For subgrid motion modeling, a Large-Eddy Simulation Smagorinsky model was implemented.
The minimum, time-average and maximum Nusselt numbers on the boundaries were calculated. The dynamics of fluid structures were analyzed to reveal the instability mechanisms and transition to turbulence. Results disclose Rayleigh-Taylor instabilities as a dominant mechanism for turbulence appearance, which occurs when the Rayleigh number is increased over 108.
The structure dependence of fluid motion at high Rayleigh numbers makes the time-average of heat transfer hard to assess. The time-average values should be supplemented with probability distributions of related variables.
New Model of Higher Moments for Describing Stratified and Swirled Turbulent Flows
Authors: Ilyushin Boris B. , Yakovenko Sergey N. 
Published: December 2021

Abstract
A new model of the fourth-order cumulants has been elaborated for describing non-local turbulent transfer in stratified flows allowing the field of applicability of turbulence model to be significantly widened. An algebraic version of the fourth-order cumulants model does not require additional empirical information. An algebraic model for third-order moments is also formulated on the base of standard models correction for buoyancy and swirl effects. The models have been tested for a turbulent flow in a rotating pipe. These results and results of modelling turbulent transfer in the convective atmospheric boundary layer let us conclude that the developed algebraic approximations for higher moments can be applied for both parameterization of turbulent diffusion processes in the transport equations and computation of higher-order moments in turbulent stratified and swirled flows.
Thermal Analysis of Stacked Ni-MH Battery
Authors: Hisano Katsumi , Iwasaki Hideo , Ishizuka Masaru , Yamane Tetsuya 
Published: December 2021

Abstract
Numerical analysis was carried out to evaluate the temperature rise and charge retention of Ni-MH batteries as pallet loads. In this paper, thermal analysis of pallet loads which contain 2400 mAh Ni-MH batteries is considered as a test case. To reduce computational load, thermal analysis was performed in three stages. Measured and calculated temperature rise of the load showed good agreement, and it can be observed that there exists an appropriate charge retention of the battery to sustain high retention during transportation.
Condensation of R134a Flowing Inside Horizontal and Vertical Helicoidal Pipe
Authors: Kang H. J. , Lin C. X. , Ebadian M. A. 
Published: December 2021

Abstract
Condensing heat transfer characteristic of an ozone-friendly refrigerant HFC-R134a (Hydrofluorocarbon R134a) flowing inside a 12.7mm helicoidal tube was investigated experimentally to obtain heat transfer data and correlations. For this long helicoidal pipe at horizontal and vertical helicoidal positions, heat transfer measurements were performed for the refrigerant flow mass fluxes from 100 to 400 kg/m2/s, in the cooling water flow Reynolds number range of 1500 &lt; Rew &lt; 9000 at fixed system temperature (33°C) and cooling tube wall temperature (12°C and 22°C). Experimental results show that, with the increase of mass flux, the overall condensing heat transfer coefficients of R134a increase. However, with the increase of mass flux (or the cooling water flow Reynolds number), the refrigerant side heat transfer coefficients decrease. The effects of cooling wall temperature on heat transfer coefficients were considered. Predictive correlations valid over the above water flow Reynolds number ranges and refrigerant flow mass fluxes were proposed. Helicoidal pipe heat transfer characteristics were compared with data from literature reports for horizontal straight tube. Experimental results show that helicoidal pipe, especially at horizontal position, conducts a much better heat transfer characteristic than that of horizontal tube even it was grooved. The helicoidal pipe’s position plays a very great role on heat transfer characteristic with 100 percent higher results at a horizontal position than that of vertical position.