bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Measurements and Computations of Heat Transfer and Flow Friction Factor in a Staggered Pin Fin Array
Authors: Ames Forrest E. , Solberg Christopher S. , Goman Michael D. , Curtis Daniel J. , Steinbrecker Bradley T. 
Published: November 2020

Abstract
This paper presents experimental measurements and CFD calculations for heat transfer and flow friction factor in a staggered pin fin array. The heat transfer and flow friction factor data are taken in a constant temperature facility and are acquired over a Reynolds number range of 1500 to 31,000. The array is comprised of eight rows of pins spaced at 2.5 diameters in the streamwise and spanwise directions with a pin height of two diameters. The heat transfer data are presented in terms of both average array data and row resolved data. The data accurately match the recent pin fin correlation of Chyu et at. [1] and extend its range to lower Reynolds numbers. The flow friction factor data accurately match the low and high Reynolds number data of Metzger et al. [2].
The steady state computations for a 2D and 3D representation of the geometry are performed and compared with archival correlations and the present data. The calculations are performed using a general purpose commercial solver (FLUENT 5.3 [3]) and apply the realizable k-ε model of Shih et al. [4] along with a two layer model which solves the k equation in the near wall region. Generally, the calculations perform relatively well with the 2D calculations matching the literature correlations slightly better than the 3D calculations.
Computational Study of a Two-Passage Turbine Guide-Vane Cascade With End-Wall Contouring
Authors: Zhu Bin , Lin Yu-Liang , Shih Tom I-P. , Oke Rohit , Simon Terry W. , Chyu Minking 
Published: November 2020

Abstract
CFD simulations based on the ensemble-averaged compressible Navier-Stokes equations, closed by two different turbulence models — the standard k-ε model with wall functions and the two-layer model of Chen and Patel — were performed to guide the design of a two-passage experimental setup, which models a linear cascade by using only three airfoils. Results generated show that the angle of the tailboards can be adjusted to give the same flow rates through the two passages. Results also show that once the flow rates are nearly the same, the pressure distributions become nearly periodic, indicating that the two-passage experimental setup does indeed mimic a linear cascade. The discrepancies between the two-passage experimental setup and a truly periodic linear cascade include the location of the stagnation zone about the airfoil’s leading edge and the shape of the pressure distribution in the trailing-edge region.
Computational Analysis of Pitch-Width Effects on the Losses of Turbine Blades
Authors: Xu C. , Amano R. S. 
Published: November 2020

Abstract
A three-dimensional computational code was developed for solving a time-averaged flow within a turbine blade-to-blade region using a novel time-marching method. A new concept of incorporating dissipation terms into the time derivative terms was proposed to allow the code to have the capability of handling both incompressible and compressible flows. The computational code was validated through comparisons with experiments in a turbine stator and was used to investigate the influence of secondary flow depending on different pitch-width ratios of the turbine blades. Detailed secondary flows as well as loss profiles in different sizes of root pitch-width ratio were presented. The results of this study provide useful information for evaluation of the secondary flow effects due to pitch-width ratio influence for the future turbine designs.
Generating Offsets That Are Homologous to Their Skeletons
Authors: Thompson David , Crawford Richard 
Published: November 2020

Abstract
In this paper we present a method for generating an offset surface from a subcomplex of a regular triangulation such that the surface has the same topology as the subcomplex. We assume that a subcomplex has been generated by specifying input points and their weights. The subcomplex may contain points, lines, triangles, and tetrahedra based on the values of the weights.
The offset from the subcomplex, or skeleton, is restricted to lie inside a union of balls centered around the input points with radii related to the weights of the input points. This restriction forces the offset and the skeleton to have the same homology. The homology groups are easy to compute for the skeleton. In this way, a designer can impose both geometric and topological constraints on a model. Also, the skeleton can be thought of as a graph to which design information can be attached; for instance, we show how the portion of the offset surface associated with each input point can be easily identified and used in lumped parameter analysis for simulations. Functional representations of a design might also be attached to the skeleton as well.
A Web-Based Distributed Product Realization Environment
Authors: Xiao Angran , Choi Hae-Jin , Kulkarni Rahul , Allen Janet K. , Rosen David , Mistree Farrokh , Feng Shaw C. 
Published: November 2020

Abstract
A web-based, a platform-independent software framework is developed to integrate distributed, heterogeneous software resources into an open product design/manufacturing system. We identify failings in previous systems, P2 and PRE-RMI, and propose systematic methods for the design of a software framework and implementation of a communication mechanism within that framework. An activity architecture of the product realization process is constructed based on the necessary interaction among engineers. This activity architecture is mapped onto a coordination architecture specifying the framework of the distributed software tools and resources. Thus the software framework is constructed based on the requirements of collaboration and communication between engineers. In addition, instead of exchanging information between engineers, the information flows are refined into message flows and data flows. Short commands and specific results are broadcast within product development groups in the form of messages, and large files are transferred directly as data flows. A prototype platform independent software framework, Web-based Distributed Product Realization Environment (WEB-DPR), is presented and its use in designing and manufacturing a high-speed robot arm is described.
A Declarative Feature-Based Cross Sectional Design Tool for Surface Micromachined MEMS
Authors: Gao Feng , Sarma Radha 
Published: November 2020

Abstract
Currently MEMS designers begin the geometric design of a new device by creating the masks that would lead to a geometric model. At the macro-level, this would be analogous to generating a geometric model from the tool paths, which would be a very tedious task. In contrast to MEMS designers, designers of macro-devices have the advantage of starting with a geometric model and of being able to directly visualize or manipulate their designs. The geometric model is then queried to generate manufacturing-related data. In the case of surface micromachined MEMS, until very recently, there has been no systematic means to automatically generate the mask data after a geometric model of the MEMS device has been refined through behavioral simulations. This has resulted in the lack of geometric design tools that would potentially aid the MEMS designer in creating MEMS devices.
This paper focuses on developing a declarative, feature-based design tool for the cross sectional design of surface micromachined MEMS, which enables MEMS designers to create fabrication-ready models of MEMS devices in an intuitive environment that is transparent to the fabrication process. The structured nature of MEMS fabrication processes has been exploited to develop a design-by-features approach tailored to MEMS design. In comparison to most macro-design tools where a design-by-features approach does not provide full flexibility, in the case of MEMS, the structured nature of the fabrication process allows for a comprehensive definition of design features that can be systematically mapped to fabrication features. In addition, feature dependency graphs and constraint graphs enable feature reparametrization leading to the easy manipulation of MEMS designs.
Relative Cooling: Part II — Design Considerations and Efficiency
Authors: Constantin Sandu , Brasoveanu Dan 
Published: November 2020

Abstract
Cooling systems with liquid for gas turbine engines that use the relative motion of the engine stator with respect to the rotor for actuating the coolant pump can be encapsulated within the engine rotor. In this manner, the difficult problem of sealing stator/rotor interfaces at high temperature, pressure and relative velocity is circumvented. A first generation of such cooling systems could be manufactured using existing technologies and would boost the thermal efficiency of gas turbine engines by more than 2% compared to recent designs that use advanced air-cooling methods. Later, relative cooling systems could increase the thermal efficiency of gas turbine engines by 8%–11% by boosting the temperatures at turbine inlet to stoichiometric levels and recovering most of the heat extracted from turbine during cooling. The appreciated high reliability of this cooling system will allow widespread use for aerospace propulsion.
Optimum Design Using Search Agents
Authors: Miyashita Tomoyuki , Yamakawa Hiroshi 
Published: November 2020

Abstract
Many optimization methods and practical softwares have been developing for many years and most of them are very effective, especially to solve practical problems. But, non-linearity of objective functions and constraint functions, which have frequently seen in practical problems, has caused a difficulty in optimization. This difficulty mainly lies in the existence of several local optimum solutions.
In this study, we have proposed a new global optimization methodology that provides an information exchange mechanism in the nearest neighbor method. We have developed a simple software system, which treated each design point in optimization as an agent. Many agents can search the optima simultaneously exchanging the their information. We have defined two roles of the agents. Local search agents have roles on searching local optima by such an existing method as the steepest decent method and so on. Stochastic search agents investigate the design space by making use of the information from other agents. Through simple and several structural optimization problems, we have confirmed the advantages of the method.
Posture Prediction Versus Inverse Kinematics
Authors: Abdel-Malek Karim , Yu Wei , Mi Zan , Tanbour E. , Jaber M. 
Published: November 2020

Abstract
Inverse kinematics is concerned with the determination of joint variables of a manipulator given its final position or final position and orientation. Posture prediction also refers to the same problem but is typically associated with models of the human limbs, in particular for postures assumed by the torso and upper extremities. There has been numerous works pertaining to the determination and enumeration of inverse kinematic solutions for serial robot manipulators. Part of these works have also been directly extended to the determination of postures for humans, but have rarely addressed the choice of solutions undertaken by humans, but have focused on purely kinematic solutions. In this paper, we present a theoretical framework that is based on cost functions as human performance measures, subsequently predicting postures based on optimizing one or more of such cost functions. This paper seeks to answer two questions: (1) Is a given point reachable (2) If the point is reachable, we shall predict a realistic posture. We believe that the human brain assumes different postures driven by the task to be executed and not only on geometry. Furthermore, because of our optimization approach to the inverse kinematics problem, models with large number of degrees of freedom are addressed. The method is illustrated using several examples.
On the Extraction of Kinematic Behavior From Optimal Compliant Topologies With Application to Number Synthesis of Linkages
Authors: Saxena Anupam , Ananthasuresh G. K. 
Published: November 2020

Abstract
This paper presents a number of systematically designed compliant topologies and discusses how the intrinsic kinematic behavior can be extracted from them. This is then applied to the number synthesis of linkages. Many techniques developed for number synthesis of linkages enumerate numerous possible kinematic chains, but few can select the best configuration among them. A systematic computational approach that can select the best configuration based on kinetostatic design specifications is presented here. This is a serendipitous result that transpired when two well-developed design techniques for compliant mechanisms were combined. A number of examples with non-intuitive design specifications are included to illustrate the new approach to number synthesis. The examples also illustrate that the kinematic behavior is aptly captured in the elastic mechanics-based topology optimization method to compliant mechanism design. Dimensional synthesis is also accomplished in the same procedure, which is an added benefit of this approach.
Towards the Design of Heterogeneous Compliant Mechanisms
Authors: Yin Luzhong , Ananthasuresh G. K. 
Published: November 2020

Abstract
Inspired by nature’s multi-material compliant designs and the capability of modern manufacturing methods to make multi-material components without assembly, and motivated by the versatility and enhanced functionality with multi-material designs, we formalize the notion and the design of heterogeneous compliant mechanisms. In the topology optimization of compliant mechanisms, a fictitious density function is often used for material interpolation to overcome the computational difficulties encountered in the large “0-1” type integer programming problem. In this paper, we illustrate that a gradually formed continuous peak function can be used for material interpolation. One of the advantages of introducing the peak function is that multiple materials can easily be incorporated into the topology optimization without increasing the number of design variables. By using the peak function and the optimality criteria method, we synthesize compliant mechanisms with multiple materials with and without the material resource constraint. The numerical examples include the two, three, and four material designs where void is treated as one material. This new design method enables us to optimally juxtapose stiff and flexible materials in heterogeneous compliant mechanisms that can be built using a variety of modern manufacturing methods.
Solution Selectors: A User-Oriented Answer to the Geometric Constraint Multiple Solution Problem
Authors: Bettig Bernhard , Shah Jami 
Published: November 2020

Abstract
The development of solid modeling to represent the geometry of designed parts and the development of parametric modeling to control the size and shape have had significant impacts on the efficiency and speed of the design process. Designers now rely on parametric solid modeling, but surprisingly often are frustrated by a problem that unpredictably causes their sketches to become twisted and contorted. This problem, known as the “multiple solution problem” occurs because the dimensions and geometric constraints yield a set of non-linear equations with many roots. This situation occurs because the dimensioning and geometric constraint information given in a CAD model is not sufficient to unambiguously and flexibly specify which configuration the user desires.
This paper first establishes that only explicit, independent solution selection declarations can provide a flexible mechanism that is sufficient for all situations of solution selection. The paper then describes the systematic derivation of a set of “solution selector” types by considering the occurrences of multiple solutions in combinations of mutually constrained geometric entities. The result is a set of eleven basic solution selector types and two derived types that incorporate topological information. In particular, one derived type “concave/convex” is user-oriented and thought to be very useful.
Development of Parallel Architecture Spatial Compliant Manipulators
Authors: Canfield S. L. , Beard J. W. , Parsons R. D. , Lobontiu N. , Paine M. , Paine J. 
Published: November 2020

Abstract
This paper will present the development of two spatial compliant manipulators suitable for fabrication at a miniature or micro level and positioning on a micro or nano scale. These compliant manipulators are based on a parallel architecture that provides rotational motion about two axes and translations in one to three directions. These compliant devices form the first in a class of such compliant manipulators that combine the characteristics of parallel manipulators with the low cost, small-scale capabilities resulting from a compliant structure design. These manipulators will be developed as lumped-compliance devices, having architectures with relatively rigid links and compliant joints designed to render nearly equivalent kinematic motion. Appropriate kinematic models are developed for design and control. The work is then demonstrated through development of a 3 degree-of-freedom miniature compliant manipulator (MCM) and a five degree-of-freedom (dof) compliant manipulator for micro-pointing applications.
Concurrent Parametric Design Using a Multifunctional Team Approach
Authors: Chen Li , Li Simon 
Published: November 2020

Abstract
A multifunctional team approach is suggested to tackle concurrent parametric design. In this approach, concurrent parametric design is modeled and formulated using optimization formalism in a multi-team computing environment, where each team is responsible for a distributed task as part of the whole design. To formalize a design task, the goal and constraints of each team are expressed as analogous to those treated in an optimization problem. The provision of satisfaction metrics is for quantifying how each team, from its perspective, favors a generated design. Coordination paradigms are formalized with characterization of the underlying team interactions in multi-team design. The notions of responsibility and controllability are introduced to regularize design protocols so that the complexity of modeling the mixed team design can be handled. As a result, a generalized team model is constructed to facilitate multi-team based design optimization, which is further illustrated through a design example.
The Use of Metamodeling Techniques for Optimization Under Uncertainty
Authors: Jin Ruichen , Du Xiaoping , Chen Wei 
Published: November 2020

Abstract
Metamodeling techniques have been widely used in engineering design to improve the efficiency in simulation and optimization of design systems that involve computationally expensive simulation programs. Many existing applications are restricted to deterministic optimization. Very few studies have been conducted on studying the accuracy of using metamodels for optimization under uncertainty. In this paper, using a two-bar structure system design as an example, various metamodeling techniques are tested for different formulations of optimization under uncertainty. Observations are made on the applicability and accuracy of these techniques, the impact of sample size, and the optimization performance when different formulations are used to incorporate uncertainty. Some important issues for applying metamodels to optimization under uncertainty are discussed.
Computer Assisted Navigation Systems for Hip and Knee Reconstructive Surgery: Evaluation of Traditional Surgical Technique
Authors: DiGioia Anthony M. , Picard Frederic , Jaramaz Branislav , Sell David , Moody James C. , Playkseychuk Anton , Levison Tim J. , Nikou Constantinos , LaBarca Richard S. , Muir Patrick 
Published: November 2020

Abstract
In this paper we describe a surgical navigation system named HipNav (Hip-Navigation) for THR and KneeNav (Knee-Navigation) for TKR with an emphasis on using these systems as a real time intraoperative measurement tool (these enabling technologies are the surgical toolbox of the future). This approach will permit the direct comparison of patient outcomes with measurable surgical techniques.
Rational Design Automation by Dichromatic Graphs
Authors: Escanaverino Jose Martinez , Soriz Jose A. Llamos , Toll Alejandra Garcia , Cardenas Tania Ortiz 
Published: November 2020

Abstract
As the complexity of mechanical design increases, due to larger size mathematical models, the need for rational design procedures also goes up. As shown elsewhere, dichromatic graphs have proven their value as tools for the algorithmic education of mechanical engineers. This paper analyzes the worth of such graphs as a means to achieve rational design solutions in complex industrial problems. The paper covers plant maintenance and research & development professional case studies. A real-life problem in electromechanical system reengineering is the first application example. Attention is also given in the paper on the partitioning of large problems, involving many variables and relations. The design of a planetary gear unit, with a three-digit number of elements in the mathematical model, is an example problem in this area. In addition, changes and extensions to the computational problem solving theory are included.
Automatic Determination of the Small Displacements in a Mechanical Assembly of Two Parts
Authors: Forster Charles , Doré Emmanuel 
Published: November 2020

Abstract
Herein is proposed an automatic method by which the precision of a joint realized by the mechanical assembly of two parts may be totally determined. This precision depends on the dimensional and geometrical defaults existing in the parts, and is materialized by additional small displacements of the parts superposed with the kinematics of the joint.
In a first step, the parts are represented by their geometrical entities, and the possible contacts existing between these entities. By ≪ sliding ≫ the parts around their nominal position, i.e. by opening or closing contacts between surfaces, one defines a new configuration of the assembly.
In a second step, we give the conditions that this new configuration must fulfill to be physically acceptable. No parasitical motion is accepted, it must be possible to compute the small displacement torsor between the two configurations. And finally, no geometrical interferences are tolerated between the parts.
In a third step, we apply this method on a simple but instructive bidimensional example.
Modeling of an Electroactive Steerable End-Effector for Minimally Invasive Surgery
Authors: Aguilera William M. , Frecker Mary I. , Haluck Randy 
Published: November 2020

Abstract
A model has been developed to design a new active, steerable end-effector for minimally invasive surgery. Active material is incorporated into the surgical instrument to increase the degrees of freedom available to the surgeon. This paper focuses on the modeling of the end-effector using both piezoelectric ceramic and electroactive polymer (EAP) materials. The end-effector design consists of a number of bimorph actuator sections in series with each active layer being individually controlled. Each section may behave as either a bimorph or a unimorph actuator, where in the case of unimorph one of the active layers is passive. By varying the strength and direction of the electric field across each section, a prescribed overall shape can be achieved to allow the user to steer the device. The piezoceramic device is modeled using strain energy methods to predict the quasi-static force-deflection behavior. In the EAP model, experimental data for the electrostrictive P(VDF-TrFE) copolymer is used to model the non-linear relationship between the electric field and the induced strain. Due to the large deflections achievable with the EAP, a model for large deflections beams is also used. Modeling is carried out using MATLAB and then the behavior of piezoelectric ceramic is compared to that of electro-active polymer (EAP).