bluuebunny/crossref_metadata_2025_split huggingface dataset:
Near-Wall Velocimetry in the Impingement-Zones of a Microdroplet and a Round Jet Stream
Authors: Kanjirakat Anoop , Sadr Reza , Alvarado Jorge 
Published: April 2021

Abstract
Near-wall fluid velocimetry in the impingement zone of a microdroplet stream on a flat surface is reported utilizing microparticle tracking velocimetry (μPTV). The results are then compared with the near-wall fluid velocimetry in the impingement region of a steady microjet stream. The presence of tracer particles in the fluid results in a small random movement of the droplets away from the orifice axis, causing a change in the location of the droplet impingement center. A new method to find the center of impingement is described, and an algorithm is developed to obtain the radial velocities in the impingement zone at three out-of-plane heights of 2, 7, and 10 ± 2 μm from the wall. Single-frame double-exposed images of low loading fluorescent tracer particles are used for the experiments. As the impingement frequency of the droplet stream is much higher than the image-capturing rate of the camera, each double-exposed image corresponds to a random instance within the impingement period of the droplets. The presented results show the occurrence of a higher normalized root-mean-square along with positive skewness of the measured radial velocity values for the droplet stream. These indicate higher velocity fluctuations or fluid mixing characteristics induced by the droplet-crown propagation for the droplet stream when compared to that of a jet stream. The near-wall velocity measurements support previously reported observations of the enhanced convection heat transfer characteristics for a droplet stream case.
Automated Structural Design Based on Expert’s Knowledge and Fuzzy Control
Authors: Yagawa Genki , Mochizuki Yoshihiko , Yoshimura Shinobu 
Published: April 2021

Abstract
This paper describes an application of both expert’s knowledge and fuzzy control to the automated design of structures subjected to coupled phenomena such as structural deformation, fracture, heat conduction and so on.
As a basic strategy of designing structures considering coupled phenomena, the “generate and test” strategy is generally adopted because of its simplicity and broad applicability. Although expert’s knowledge is often utilized as one of design modification techniques in the strategy, it is not so good at quantitative modification. Then a fuzzy control technique is introduced in the present study to improve its ability of quantitative design modification.
A two-dimensional model of the fusion first wall with a cooling channel is designed to demonstrate effectiveness of the present technique.
An Intelligent Knowledge Based Approach to Support Engineering Design Practice
Authors: Chern Jyh-Huei 
Published: April 2021

Abstract
Today, engineering designs are tackling projects of increasing complexity and cost. The constraints are getting more complex, there are new materials and processes to exploit and stricter regulations and legal requirements to satisfy. Making products more quickly and efficiently is even more important in these times of increasing economic competition. Over recent years, use of computer tools in the design-analysis-manufacture stages has led to decreased lead times and reduced product costs. In particular, in the engineering design process, it has become clear that more extensive computer based support tools would result in greater gains. These include tools that help the designer maintain consistency in the design representation, help in documentation of information such as design intent, perform knowledge based manufacturing analysis and help in the generation of intelligent manufacturing plans. Progress has been made in the representation of design entities, as can be seen, for example, in geometric modeling. However, as this article point out, the techniques and methodologies underlying current Computer-Aided Design (CAD) systems are an insufficient basis for realizing automation of the engineering design process. This article proposes that an integration of Artificial Intelligence (AI) techniques with geometric modeling systems can better meet the requirements of Computer-Aided Engineering (CAE) design practice.
An Opportunistic Approach to Conceptual Design
Authors: Shanmugavelu Ilango , Esterline Albert , Riley Donald R. , Erdman Arthur G. 
Published: April 2021

Abstract
This paper addresses automation of the conceptual design stage of the overall design process, the stage that contributes the most to the cost and quality of the final product. An opportunistic constraint-based approach to conceptual design is proposed here. This approach combines some important aspects of the constraint-based transformational approach (for strongly connected systems) with aspects of the decompositional approach (for weakly connected systems) through the ability to change focus from one component to another depending on the available information and the ability to refine constraint networks hierarchically. Thus this approach enables one to address problems, such as linkage synthesis, that fall between strongly connected systems and weakly connected systems. Here design problem solving is basically viewed as an instance of the constraint satisfaction problem. Constraints are represented using hypergraphs and are manipulated through hypergraph grammars. The design strategy proposed here includes techniques to reorder the domain of a variable, to select the free choices of variables in an under-constrained system, and to select the “generator” set of constraints in an over-constrained system. A classification of constraints along with representation and reasoning guidelines is presented as a step toward implementing our approach in a way that exploits the nature of different types of constraints. An application is being developed in the linkage synthesis domain to demonstrate and validate the proposed approach.
Data Filtration and Distributed Computer Architecture for Expert Systems
Authors: Trovato Stephen A. , Touchton Robert A. 
Published: April 2021

Abstract
The timely recognition and accurate classification of emergency situations is an important task for nuclear plant operators. The Reactor Emergency Action Level Monitor (REALM) expert system was developed to provide advice to operators during emergency situations. A technique for filtering plant sensor data was developed for REALM and is broadly applicable to power plant monitoring tasks. Innovative computer architecture and verification and validation methods were developed during a research program to implement REALM at Con Edison’s Indian Point 2 nuclear plant.
A PHIGS+ Model Rendering System for Simulation of Spatial Mechanisms
Authors: Montgomery David E. , Keil Mitchel J. , Myklebust Arvid 
Published: April 2021

Abstract
A device independent system is described for the visualization, modeling, and animation of spatial mechanisms and robots. New ideas and methods are presented to simplify the interactive specification of scene rendering and color parameters using the ISO standard for 3-D graphics, the Programmer’s Hierarchical Interactive Graphic System (PHIGS) and its extensions PHIGS+.
The parallels between the PHIGS hierarchical structure and spatial mechanism modeling are described from the level of mechanism through links, joints, geometry primitives to PHIGS graphics primitives.
Perception and evaluation of spatial mechanism designs are significantly improved by the use of shaded, lighted, depth cued models under animation. The method is coupled to new algorithms for automatic interference detection and reshaping of mechanism links to avoid collisions.
The suitability of PHIGS+ for the modeling and simulation of open loop mechanisms is also described. Examples are presented for rendering and animation of spatial mechanisms on a Raster Technologies (Alliant) GX4000 workstation with a hardware based PHIGS+ graphics subsystem, UNIX, NeWS, and C.
Simulation of Range-Finding Devices by Geometric Modelling
Authors: Yao H. , Dong Z. , Podhorodeski R. 
Published: April 2021

Abstract
The development and testing of object recognition algorithms for range-finding devices requires range-data for a wide variety of scene objects and environments, and further requires an appreciation of the accuracy associated with range-data. A method for generating pseudo (simulated) range-data, based on geometric scene models and modified z-buffer algorithm, is presented in this work. The method provides a versatile and flexible tool for research on 3-D object recognition. Initial investigation of the accuracy associated with range-finding devices is considered. An analytical model for a range-finding device is developed using a homogeneous matrix representation. Differentiation of the resulting object position coordinates is utilized to examine the error in the object position coordinates resulting from relevant device mechanism inaccuracies.
Increasing Productivity Using Parametric Data and Macros
Authors: Gorman Robert W. 
Published: April 2021

Abstract
Computer-aided Engineering (CAE) has successfully helped engineers in the 1980’s to decrease the product development cycle. This has allowed companies to define high-quality, competitively priced products. In the 1990’s, companies must expand the role of CAE to help decrease the development cycle even more (i.e., increase the productivity of CAE). This paper will discuss two modeling techniques that can help designers/analysts initially define a computer model and automatically update this model when a component is altered. These techniques are the ability to define the model in terms of parametric data and to customize software packages to fit a company’s particular needs, by using macros. Designers who produce variations of a basic design or who model components geometrically based on other components will be able to increase their productivity using these techniques. Several examples will be used to illustrate how these techniques will increase productivity and how automatic design optimization may be used.
A Computer-Aided Environment for Analysis and Design of Mechanical Systems
Authors: Lankarani Hamid M. , Bahr Behnam , Motavalli Saeid 
Published: April 2021

Abstract
This paper presents the description of an ideal tool for analysis and design of complex multibody mechanical systems. It is in the form of a general-purpose computer program, which can be used for simulation of many different systems. The generality of this computer-integrated environment allows a wide range of applications with significant engineering importance. No matter how complicated the mechanical system under consideration is, a numerical multibody model of the system is constructed. The governing mixed differential/algebraic equations of motion are automatically formulated and numerically generated. State-of-the-art numerical techniques and computational methods are employed and developed which produce in the response of the system at discrete time junctures. Postprocessing of the results in the form of graphical images or real-time animations provides an enormous aid in visualizing motion of the system. The analysis package may be merged with an efficient design optimization algorithm. The developed integrated analysis/design system is a valuable tool for researchers, design engineers, and analysts of mechanical systems. This computer-integrated tool provides an important bridge between the classical decision making process by an engineer and the emerging technology of computers.
Compensation of Robot Joint Variables Using Special Jacobian Matrices
Authors: Mirman C. R. , Gupta K. C. 
Published: April 2021

Abstract
In dealing with an industrial manipulator, the end-effector accuracy is a major concern. The positioning of the end-effector is determined by the controller which utilizes the data from a closed-form kinematic inversion. The closed-form inversion uses nominal, i.e. manufacturer specified, values of link lengths, twists, and offsets. Due to manufacturing tolerances, set-up, and usage, these nominal parameters may be inaccurate. If the nominal parameters contain built-in error values, the closed-form kinematic inversion will yield incorrect joint values, and the actual end-effector position will deviate from its desired position.
One may use a parameter identification method to identify the position-independent error parameter values. This paper assumes that this has been done and it presents an Iterative Compensation Algorithm (ICA) through which the identified position-independent parameter error values may be used to correct the joint values which are obtained through the closed-form kinematic inversion. The Denavit and Hartenberg (D-H) parameters (θ s α a) are used to model the given M-jointed manipulator, and a set of four special Jacobian matrices (Jθ, Js, Jα, and Ja) are formulated. The iterative compensation algorithm allows one to determine the M unknown position-dependent joint error values, by using these four special Jacobian matrices. The improvements obtained through the use of the compensation algorithm will be presented for regular trajectories, as well as when the robot nears certain singularity conditions. Since it is important to know a priori a definite number of iterations which must be performed, the level of compensation after a fixed number of iterations is also studied. Through the presentation of numerous examples, it is shown that the proposed compensation algorithm is simple and straightforward to implement, and it increases the end-effector accuracy.
Variational Solid Modeling for Tolerance Analysis
Authors: Gupta Suvajit , Turner Joshua U. 
Published: April 2021

Abstract
Variational solid modeling is concerned with the development of solid models that allow for variation. In particular, this paper is motivated by the use of variational solid models for the analysis of design tolerances. Variations are applied to a part boundary model by independently varying each surface. This paper addresses the following significant problems: removal of excess sources of variation that produce rigid-body motion; handling of incidences and tangencies; and modeling of form variations. The application of these techniques to the solution of tolerancing problems is briefly discussed.
Non-Newtonian Flow Over a Wedge With Injection or Suction
Authors: Garg Vijay K. 
Published: April 2021

Abstract
A pseudo-similarity solution is obtained for the flow of an incompressible fluid of second grade past a wedge with suction or blowing at the surface. The non-linear differential equation is solved using quasi-linearization and orthonormalization. The numerical method developed for this purpose enables computation of the flow characteristics for any value of the parameters K, a, and b, where K is the dimensionless normal stress modulus of the fluid, a is related to the wedge angle, and b is the suction or blowing parameter. A significant effect of suction or blowing on the wall shear stress is observed. The present results match exactly with those from an earlier perturbation analysis for Kx2a ≤ 0.01 but differ significantly as Kx2a increases.
Prediction of Confined Coaxial Turbulent Jet Mixing With a Streamwise Differencing Scheme
Authors: Sharif M. A. R. , Gadalla M. A. 
Published: April 2021

Abstract
Isothermal turbulent mixing of an axisymmetric primary air jet with a low velocity annular secondary air stream inside a constant diameter cylindrical enclosure is predicted. The flow domain from the inlet to the fully developed downstream locations is considered. The predicted flow field properties include the mean velocity and pressure and the Reynolds stresses. Different velocity and diameter ratios between the primary and the secondary jets have been investigated to characterize the flow in terms of these parameters. A bounded stream-wise differencing scheme is used to minimize numerical diffusion and oscillation errors. Predictions are compared with available experimental data to back up numerical findings.
Computer Aided Optimal Design of Heat Exchanger Networks
Authors: Seshadri P. , Witte Larry C. 
Published: April 2021

Abstract
A method for finding the best (optimal) operating layout of heat exchangers in complicated thermal networks is developed in this paper. Computer algorithms are developed that take advantage of pinch technology and economic considerations, and exergetic constraints as well as conventional heat and mass balances. Our goals were to achieve minimum loss of exergy between hot and cold streams subject to practical system constraints. Furthermore, resulting networks should be limited to no more units than the theoretical minimum. The ultimate goal was to minimize investment and operating costs for a set of fixed overall system constaints.
These goals were realized by developing a computer-based nonlinear multiple objective optimization algorithm that included the elements discussed above. The final solution is a synthesis of the best system using the above-described mathematical formulation. Results for a 4-stream heat exchanger network are presented in terms of the minimum temperature difference at the pinch point. The influence of the minimum temperature difference on capital cost, heat transfer area, exergetic losses and second law efficiency of various heat exchangers in the network is presented.
Computer-Assisted Optimal Design of Energy Systems
Authors: El-Sayed Y. M. , Saad Michel A. 
Published: April 2021

Abstract
Numerical methods are used to model, predict and optimize energy systems in which thermodynamic analysis is coupled with design and economic evaluation. Two examples, in which the cost objective functions are assumed, are presented. The first example is a regenerative gas-turbine cycle in which several thermodynamic and design decision parameters are optimized for the given structure are considered. The second is a steam bottoming cycle, in which structural as well as parametric changes are introduced. Structural changes assume generating steam at several pressures and parametric changes assume different pressures, pinch and terminal temperature differences and different sets of pressure losses. The essential features of a software adequate for this type of analysis are described.
Flow Analysis Procedure for Steam Turbines
Authors: Kubiak A. , Luniewicz B. , del Angel F. 
Published: April 2021

Abstract
An algorithm (computational procedure) for flow analysis of steam turbines is presented. The algorithm is specially designed for analysis of low pressure turbines but is applicable in the same way for high pressure turbines. The analysis of the flow is carried out stage by stage (or row by row). The algorithm is so designed that a turbine of known geometry can be assessed with respect to its throughput (flow) and performance capabilities at arbitrary flow rates and steam conditions. The performance parameters include stage efficiency, rotor blade loading, blade section efficiency, and all aero/thermodynamic parameters within the blade path. On the other hand the algorithm can be used for turbine design purposes. The algorithm deals with 2D flow.
The analysis starts from the last stage and proceeds up-stream. There are several iteration loops where the mass flow is computed and compared to a required value. The algorithm is capable of determining stage flow given the stage pressure and vice versa. The algorithm can be expanded to assimilate new capabilities (for example: radial equilibrium applied to rotor). The algorithm can be applied especially for upgrading the turbines of older design.
Design and Heat Integration of a Power Plant Using Multi-Objective Optimization
Authors: Seshadri P. , Witte Larry C. 
Published: April 2021

Abstract
A heat integration technique for designing a Rankine cycle power plant that is based on modelling the cycle as a multi-objective optimization problem is presented in this paper. The heat integration procedure uses the same scheme that is used in designing complex heat exchanger networks. The hot and cold streams are identified and the pinch point is determined along with minimum heating and cooling targets. An initial configuration is designed and a multi-objective nonlinear optimization formulation of the initial configuration is solved to obtain the best feedwater heater bleed rates The procedure is based on a Rankine cycle thermodynamic simulation, program, along with exergy accounting and other applications of heat integration techniques.
The best solution values of the power plant variables have been determined for a typical Rankine cycle base plant by solving a compromise decision support problem (DSP) with a solver called DSIDES. Variation of thermal and exergetic efficiency of the power plant with feedwater heater flow rates was investigated. The heat integration of the power plant based on pinch technology for the heat recovery streams showed that fuel savings up to 1% are achievable. When translated to dollars saved, these are sigificant for large power stations.
Thermal Characteristics of Kickless Welding Cables Using Finite Element Analysis
Authors: Heist James , Berry K. J. 
Published: April 2021

Abstract
A new welding cable prototype, similar to a design by Watteredge-Uniflex Inc., contains six 30 AWG braided copper strands. The strands are of herringbone rope construction and have a non-conductive EPDM rubber star separator to maintain strand positioning and to equally distribute cooling water through the cable. The cable has a low inductive reactance to minimize operating temperatures and wear.
Transient and steady state heat transfer was analyzed in a prototype cable using Finite Element Analysis (FEA) combined with Computer Aided Drafting (CAD). The analysis numerically determined catastrophic failure times after sudden loss of coolant and developed a computer simulation model for future parametric studies. The FEA model is generated with eight node quadrilateral elements, and the analysis includes internal heat generation rates due to temperature dependent resistance in the copper strands. The FEA results are presented with a discussion of the mesh generation and analysis software.
Numerical Simulation of Supersonic Combustion in Quasi One-Dimensional Flow
Authors: Yip T. Gary 
Published: April 2021

Abstract
Supersonic combustion induced by a two-shock system has been studied using a chemical nonequilibrium, quasi one-dimensional flow model. The combustion of stoichiometric, premixed H2-air is described by a chemistry model which consists of 11 species and 28 reactions.
The freestream Mach numbers used in this calculations are 8, 10 and 12. The initial pressure is 0.01 atm and temperature 300 K. The first of the two shocks is a conical shock and the second is its reflection. Supersonic combustion has been predicted to occur at combustor pressures between 0.8 and 2.9 atmospheres, and temperatures between 1500 and 3000 K. The Mach number of the flow in the combustor is between 1.7 and 4. These combustor conditions are typical of the future hypersonic propulsion systems. The results also show the changes in the composition of the flow during the induction and heat release phases.
The two-shock system is assumed to be generated by a cone. For Mach 8, 10 and 12, the minimum cone angle for generating a strong enough two-shock system to induce supersonic combustion has also been identified.