Information sharing and exchange in the context of product lifecycle management: Role of standards

This paper introduces a model of the information flows in Product Life cycle Management (PLM), serving as the basis for understanding the role of standards in PLM support systems. Support of PLM requires a set of complementary and interoperable standards that cover the full range of aspects of the products’ life cycle. The paper identifies a typology of standards relevant to PLM support that addresses the hierarchy of existing and evolving standards and their usage and identifies a suite of standards supporting the exchange of product, process, operations and supply chain information. A case study illustrating the use of PLM standards in a large organization is presented. The potential role of harmonization among PLM support standards is described and a proposal is made for using open standards and open source models for this important activity.     

EDXRF analysis of beach rock samples of Andaman Island

B Elemental contents of beach rock samples were analyzed using EDXRF. The samples were collected from three locations of Andaman Island. The Al, Ca, K, Fe, Ti, Si, V, Co, Cu, Ba, Zn, Ph, Cd and Mn contents were determined. The geochemical behavior of elements in the region is discussed. The elemental contents of beach rock samples from Andaman Island are much below the values of both earth crust and that of Tamilnadu region. However,content of the biogenic element Ca was the highest of all dements. This is due to the typical beach rock formation.     

Forced convection heat transfer in tube banks in cross flow

The forced convection heat transfer characteristics for an incompressible, steady and Newtonian fluid flow over a bundle of circular cylinders has been investigated numerically. The inter-cylinder hydrodynamic interactions have been approximated by employing a simple cell model. The momentum and energy equations have been solved by using a finite difference based numerical solution procedure for a range of physical and kinematic conditions. Furthermore, the role of the type of thermal boundary condition, namely, a constant temperature or a constant heat flux, imposed on the surface of the cylinder has also been elucidated. Extensive results on the temperature fields, and on the variation of the Nusselt number on the surface of a typical cylinder in the assemblage have been obtained for two values of the Prandtl number (corresponding to air and water). The Reynolds number of flow was varied in the range 1-500 and the voidage of the assemblage ranged from 0.4 to 0.99 thereby covering the entire range of interest as encountered in tubular heat exchangers and in fibrous beds. The paper is concluded by presenting extensive comparisons with the limited analytical/numerical and/or experimental results available in the literature for the case of a single cylinder as well as that for tube bundles.     

Engineering of markets and artifacts

In this paper, we continue the dialog started by Roth [The Economist as Engineer: Game theory, Experimentation, and Computation as Tools for Design Economics, Fisher Schultz lecture, Econometrica 70 (2002) (4) 1341–1378] between economics and engineering in the context of design of markets. We take the position that markets and engineered artifacts are the products of a social process of design formulation. Our perspective is that designing of markets and artifacts follow the same kind of problem formulation and solution testing process. Further, we show using two case studies that the design of engineered artifacts and markets are often interdependent. In light of their similarities, methodologies for modeling and testing using theoretical, analytical, computation and physical models in engineering can inform the development of methods for testing in the design of markets. We also illustrate an example of devising a test and results of its execution thorough the use of a simple computational model of an electric power market. We conclude by summarizing the similarities between the designing of markets and artifacts and call for a continued dialogue between engineers and economists.     

The Pugh Controlled Convergence method: model-based evaluation and implications for design theory

This paper evaluates the Pugh Controlled Convergence method and its relationship to recent developments in design theory. Computer executable models are proposed simulating a team of people involved in iterated cycles of evaluation, ideation, and investigation. The models suggest that: (1) convergence of the set of design concepts is facilitated by the selection of a strong datum concept; (2) iterated use of an evaluation matrix can facilitate convergence of expert opinion, especially if used to plan investigations conducted between matrix runs; and (3) ideation stimulated by the Pugh matrices can provide large benefits both by improving the set of alternatives and by facilitating convergence. As a basis of comparison, alternatives to Pugh’s methods were assessed such as using a single summary criterion or using a Borda count. These models suggest that Pugh’s method, under a substantial range of assumptions, results in better design outcomes than those from these alternative procedures.     

Heat Transfer to Power-Law Fluids from a Heated Square Cylinder

Forced-convection heat transfer to power-law fluids from a heated square cylinder has been investigated numerically for the range of conditions 1 ≤ Re ≤ 45, 0.5 ≤ n ≤ 2.0 and 1 ≤ Pr ≤ 100 (the maximum Peclet number being 4,000). In this range of Reynolds number, the flow is known to be steady and two-dimensional. The variation of the local Nusselt number on the individual surfaces of the square cylinder and the representative isotherm plots, for both the constant-temperature and uniform-heat-flux boundary conditions prescribed on the surface of the square obstacle, are presented to elucidate the role of Reynolds number, Prandtl number, and power-law index on the heat transfer characteristics. Using the present numerical data, appropriate predictive correlations are obtained for estimating the value of the mean heat transfer coefficient in a new application.     

HEAT AND FLUID FLOW ACROSS A SQUARE CYLINDER IN THE TWO-DIMENSIONAL LAMINAR FLOW REGIME

The flow structure and heat transfer characteristics of an isolated square cylinder in cross flow are investigated numerically for both steady and unsteady periodic laminar flow in the two-dimensional regime, for Reynolds numbers of 1 to 160 and a Prandtl number of 0.7. The effect of vortex shedding on the isotherm patterns and heat transfer from the cylinder is discussed. Heat transfer correlations between Nusselt number and Reynolds number are presented for uniform heat flux and constant cylinder temperature boundary conditions.     

The Effect of a Blockage on Forced Convection Heat Transfer From a Heated Square Cylinder to Power-Law Fluids

Forced convection heat transfer characteristics of a long, heated square cylinder blocking the flow of a power-law fluid in a channel is numerically investigated in this study. In particular, the role of the power-law index n, Reynolds number Re, Prandtl number Pr, and blockage ratio β(=B/H) on the rate of heat transfer from a square cylinder in a channel has been studied over the following ranges of conditions: 0.5 ≤ n ≤ 1.8, 60 ≤ Re ≤ 160, β = 1/4, 1/2, and 0.7 ≤ Pr ≤ 50. A semi-explicit finite-volume method is used on a nonuniform collocated grid arrangement. The third-order QUICK and the second-order central difference schemes are used to discretize the convective and diffusive terms, respectively, in the momentum and energy equations. Irrespective of the type of behavior of fluid (different values of n), the average Nusselt number increases as the blockage ratio increases. Similar to the unconfined flow configuration, the average Nusselt number increases monotonically with Reynolds and Prandtl numbers for both values of the blockage ratio and for all values of power-law index considered here. Further insights into the heat transfer phenomenon are provided by presenting isotherm contours in the vicinity of the cylinder for a range of values of the Reynolds number, Prandtl number, and power-law index for the two values of β considered in this work.