Search results

The purpose of this paper is to develop an effective approach to decide design details using benchmarking to capture the existing practice in sustainable design.

This paper reports a systematic method for sustainable product design. The method uses benchmarks as references searching for design details to achieve sustainable solutions. Quality function deployment is used to guide the search process for competitive products using benchmarking to meet quantitative targets of product and to increase knowledge for sustainable design.

The proposed method can meet both functional and sustainable requirements of product design. 18.55 percent reduction in carbon equivalent emissions is achieved compared to benchmarks in wheelchair design. The research reveals that when weight, material and number of components used in product decrease, environmental footprints and cost of the product improve.

The research improves the existing method of sustainable product design. Both sustainable requirements and functional demands of product are identified from qualitative criteria to quantitative metrics using benchmarking and the life cycle assessment.

In part I uses an iterative point successive over‐relaxation (PSOR) finite difference scheme to solve the coupled unsteady Navier‐Stokes and energy equations for incompressible, viscous and laminar flows in their primitive variable form. Presents the details concerning the derivation of the solution scheme, as well as details on its computer implementation. For validation purposes, includes the results of the two‐dimensional and three‐dimensional benchmark problem of natural convection in a cavity with differentially heated vertical walls. Benchmark computations have been performed for a Prandtl number of 0.71, and different values of the Rayleigh number ranging between 10³ and 10⁶ depending on the problem. By comparison with other approaches in the literature, the scheme has been found to be accurate even for large Rayleigh numbers.

The purpose of this paper is to investigate and analyze the challenges of quality skill development in complex and large economies like India and develop innovative processes of improving employability.

The problem areas and gaps have been identified through literature survey and published reports by governmental agencies on employability and quality skill development in India. The research focuses on prevalent challenges for large-scale skill development and utilizes TRIZ (Russian acronym for “Theory of Inventive Problem Solving”) for finding innovative solutions to the grand challenge of employability.

The applied research methodology in the paper leads to a model for the “Innovation driven ecosystem for quality skill development” and also defines the role and responsibilities of each stakeholders in the ecosystem.

Solutions derived through TRIZ are qualitative in nature. The actual implication of solution needs to be tested after implementation. Further, intangible costs incurred, and harmful and useful effects cannot be easily quantified.

The parameter mapping for the TRIZ matrix was undertaken in this paper and this methodology when applied to other problem statements renders an organized process for improving total quality and innovative process management. The inventive principles were applied to find solution to contradictions and arrive at an integrated ecosystem which binds all stakeholders efficiently, to generate higher employability. The innovative solutions derived through the process are applicable to policy makers, researchers and practitioners.

The process of improving employability through quality skill development, benchmarked by the TRIZ methodology can have far reaching social implications.

The research extends the body of knowledge of TRIZ modeling concepts in areas other than engineering, and depicts a unique total quality methodology which can be easily applied for other problem-solving contexts. The contribution can serve as a reference technique/tool for improving reliability and quality through a methodical process of working out innovative solutions to solve operational problems.

Modelling accurately the transient behaviour of natural convection flow in enclosures been a challenging task because of a variety of numerical errors which have limited achieving the higher order temporal accuracy. A fourth-order accurate finite difference method in both space and time is proposed to overcome these numerical errors and accurately model the transient behaviour of natural convection flow in enclosures using vorticity–streamfunction formulation.

Fourth-order wide stencil formula with appropriate one-sided difference extrapolation technique near the boundary is used for spatial discretisation, and classical fourth-order Runge–Kutta scheme is applied for transient term discretisation. The proposed method is applied on two transient case studies, i.e. convection–diffusion of a Gaussian Pulse and Taylor Vortex flow having analytical solution.

Error magnitude comparison and rate of convergence analysis of the proposed method with these analytical solutions establish fourth-order accuracy and prove the ability of the proposed method to truly capture the transient behaviour of incompressible flow. Also, to test the transient natural convection flow behaviour, the algorithm is tested on differentially heated square cavity at high Rayleigh number in the range of 10³-10⁸, followed by studying the transient periodic behaviour in a differentially heated vertical cavity of aspect ratio 8:1. An excellent comparison is obtained with standard benchmark results.

The developed method is applied on 2D enclosures; however, the present methodology can be extended to 3D enclosures using velocity–vorticity formulations which shall be explored in future.

The proposed methodology to achieve fourth-order accurate transient simulation of natural convection flows is novel, to the best of the authors’ knowledge. Stable fourth-order vorticity boundary conditions are derived for boundary and external boundary regions. The selected case studies for comparison demonstrate not only the fourth-order accuracy but also the considerable reduction in error magnitude by increasing the temporal accuracy. Also, this study provides novel benchmark results at five different locations within the differentially heated vertical cavity of aspect ratio 8:1 for future comparison studies.

We use the finite element method to model the heat transfer phenomenon through permeable cracks in hydrothermal systems with upward throughflow. Since the finite element method is an approximate numerical method, the method must be validated before it is used to solve any new kind of problem. However, the analytical solution, which can be used to validate the finite element method and other numerical methods, is rather limited in the literature, especially for the problem considered here. Keeping this in mind, we have derived analytical solutions for the temperature distribution along the vertical axis of a crack in a fluid‐saturated porous layer. After the finite element method is validated by comparing the numerical solution with the analytical solution for the same benchmark problem, it is used to investigate the pore‐fluid flow and heat transfer in layered hydrothermal systems with vertical permeable cracks. The related analytical and numerical results have demonstrated that vertical cracks are effective and efficient members to transfer heat energy from the bottom section to the top section in hydrothermal systems with upward throughflow.

Vorticity formulations for the incompressible Navier‐Stokes equations have certain advantages over primitive‐variable formulations including the fact that the number of equations to be solved is reduced through the elimination of the pressure variable, identical satisfaction of the incompressibility constraint and the continuity equation, and an implicitly higher‐order approximation of the velocity components. For the most part, vorticity methods have been used to solve exterior isothermal problems. In this research, a vorticity formulation is used to study the natural convection flows in differentially‐heated enclosures. The numerical algorithm is divided into three steps: two kinematic steps and one kinetic step. The kinematics are governed by the generalized Helmholtz decomposition (GHD) which is solved using a boundary element method (BEM) whereas the kinetics are governed by the vorticity equation which is solved using a finite element method (FEM). In the first kinematic step, vortex sheet strengths are determined from a novel Galerkin implementation of the GHD. These vortex sheet strengths are used to determine Neumann boundary conditions for the vorticity equation. (The thermal boundary conditions are already known.) In the second kinematic step, the interior velocity field is determined using the regular (non‐Galerkin) form of the GHD. This step, in a sense, linearizes the convective acceleration terms in both the vorticity and energy equations. In the third kinetic step, the coupled vorticity and energy equations are solved using a Galerkin FEM to determine the updated values of the vorticity and thermal fields. Two benchmark problems are considered to show the robustness and versatility of this formulation including natural convection in an 8×1 differentially‐heated enclosure at a near critical Rayleigh number.

The purpose of this paper is to aim at extending the method of exponential basis functions (EBF) to solve a class of problems with singularities.

In the procedure of EBF a summation of EBF satisfying the governing differential equation with unknown constant coefficients is considered for the solution. These coefficients are determined by the satisfaction of prescribed boundary conditions through a collocation approach. The applied basis functions are available in the case of linear partial differential equations (PDEs) with constant coefficients. Moreover, the method contributes to yield highly accurate results with ultra convergence rates for problems with smooth solution. This leads EBF to offer many advantages for a variety of engineering problems. However, owing to the global and smooth nature of the bases, the performance of EBF deteriorates in problems with singularities. In the present study, some exponential-like influence functions are developed, and a few of them are added to original bases.

The new bases are capable of forming the constitutive terms of the asymptotic solution near the singularity points and alleviate the aforementioned limitation. The appealing feature of this method is that all the advantages of EBF such as its simplicity and efficiency are completely preserved.

In its current form, EBF can only solve PDEs with constant coefficients.

Application of the method to some benchmark problems demonstrates its robustness over some other boundary approximation methods. This research may pave the road for future investigations corresponding to a wide range of practical engineering problems.

Given the emphasis in today's environment on customer focus, stakeholders’ interests, public‐sector organisational performance and other methods of assessment are employed to address issues in the new public management and prevailing managerialism in measurement of public‐sector organisations around the world. Therefore, many public‐sector organisations have been encouraged to implement benchmarking as one way of satisfying the government's requirement that public organisations provide best‐value services. In order to achieve best‐value services in public‐sector organisations, benchmarking is considered to be a vital management tool and benchmarking has been used widely in private‐sector organisations. This paper focuses on providing a critical view of benchmarking to provide best‐value services to taxpayers and local businesses. The paper emphasises that, in order for benchmarking to be successful in public‐sector organisations, it is important to have a full commitment to continuous improvement, an ability to learn from others, and a commitment to implement improvement.

An existing two‐dimensional finite volume technique is modified by introducing a correction term to increase the accuracy of the method to second order. It is well known that the accuracy of the finite volume method strongly depends on the order of the approximation of the flux term at the control volume (CV) faces. For highly orthotropic and anisotropic media, first order approximations produce inaccurate simulation results, which motivates the need for better estimates of the flux expression. In this article, a new approach to approximate the flux term at the CV face is presented. The discretisation involves a decomposition of the flux and an improved least squares approximation technique to calculate the derivatives of the dependent function on the CV faces for estimating both the cross diffusion term and a correction for the primary flux term. The advantage of this method is that any arbitrary unstructured mesh can be used to implement the technique without considering the shapes of the mesh elements. It was found that the numerical results well matched the available exact solution for a representative transport equation in highly orthotropic media and the benchmark solutions obtained on a fine mesh for anisotropic media. Previously proposed CV techniques are compared with the new method to highlight its accuracy for different unstructured meshes.