Design tool

About: Design tool is a research topic. Over the lifetime, 3864 publications have been published within this topic receiving 46401 citations.

Development of a Two-Dimensional Streamline Curvature Code

Abstract: Two-dimensional (2D) compressor flow simulation software has always been a very valuable tool in compressor preliminary design studies, as well as in compressor performance assessment operating under uniform and non-uniform inlet conditions. This type of software can also be used as a supplementary teaching tool. In this context, a new streamline curvature (SLC) software has been developed capable of analyzing the flow inside a compressor in two dimensions. The software was developed to provide great flexibility in the sense that it can be used as: (a) a performance prediction tool for compressors of a known design, (b) a development tool to assess the changes in performance of a known compressor after implementing small geometrical changes, (c) a design tool to verify and refine the outcome of a preliminary compressor design analysis, and (d) a teaching tool to provide the student with an insight of the 2D flow field inside a compressor and how this could be effectively predicted using the SLC method combined with various algorithms and cascade models. Apart from describing in detail the design, structure, and execution of the SLC software, this paper also stresses the importance of developing robust, well thought-out software and highlights the main areas a potential programmer should focus on in order to achieve this. This text also highlights the programming features incorporated into the development of the software in order to make it amenable for teaching purposes. The paper reviews in detail the set of cascade models incorporated for subsonic and supersonic flow, for design and off-design operating conditions. More-over, the methods used for the prediction of surge and choke are discussed in detail. The code has been validated against experimental results, which are presented in this paper together with the strong and weak points of this first version of the software and the potential for future development. Finally, an indicative case study is presented in which the shift of streamlines and radial velocity profiles is demonstrated under the influence of two sets of compressor inlet boundary conditions.

A multidisciplinary optimization method for designing inlets using complex variables

Abstract: The Blended-Wing-Body is a conceptual aircraft design with rear-mounted, over-wing engines. Two types of installations have been considered for this aircraft: partially buried engines with boundary layer ingesting inlets and the more conventional podded engines with pylons. For both designs, the tight coupling between the aircraft aerodynamics and the propulsion system poses a difficult design integration problem. This paper presents a design method that approaches the problem using multidisciplinary optimization. A Navier-Stokes flow solver, an engine analysis method, and a nonlinear optimizer are combined into a design tool that correctly addresses the tight coupling of the problem. Gradients for the optimizer are computed using the complex variable method. Results from optimization runs on the podded installation are presented.

Integration of numerical and field-theoretical techniques in the design of single- and multi-band rectennas for micro-power generation

Abstract: We introduce an integrated design methodology for the optimization of RF-to-DC conversion efficiency of multi-band rectennas (rectifying antennas), with the aim of harvesting the RF energy available in humanized environments. Existing RF sources can either operate at known frequencies, power budgets, and locations, or can be ubiquitously available at different frequency bands, and with unknown directions of incidence and polarizations. In all cases, the RF link power budget may be extremely low. In order to harvest a significant quantity of energy, it is thus mandatory to place a very special care in the design of each part of the receiving/storing system. For this purpose, the receiving antenna must be optimized together with the rectifying circuit and the load. In our work, this is accomplished by a rigorous design tool based on the concurrent use of nonlinear/electromagnetic (EM) CAD tools and EM theory. The effectiveness of the method is demonstrated by comparing the computed and measured performance of single- and multi-band rectennas, both linearly and circularly polarized. Such antennas are designed to harvest RF energy from a variety of cellular and WiFi systems that are normally present in civil environments.

Technical and Economic Readiness Review of CFD- Based Numerical Wave Basin for Offshore Floater Design

Abstract: As Computational Fluid Dynamics (CFD) and High Performance Computing (HPC) technologies matured in many other industries, the offshore industry has begun to recognize CFD-based Numerical Wave Basin (NWB) as a design tool to evaluate offshore floater design more efficiently and with less uncertainty than the conventional ways relying on empirical methods. The recent NWB technology development has focused on the customization of CFD software for offshore design practices and validation of the developed analysis tools/procedures against physical model tests. Development has now extended to simulation of fully coupled hull-mooring-riser systems. Technology readiness of the NWB for field application is demonstrated for two benchmark problems: Vortex-induced motion of a multi-column floater Global performance of a multi-column floater in extreme wave environment The results indicates that the CFD-based numerical wave basin, although still computationally expensive, is technically ready to be a complementary tool to physical wave basin for offshore platform global performance design.

Use and Adaptation of Precedents in Architectural Design: Toward an Evolutionary Design Model

Abstract: For centuries, architects have re-used design precedents in the conception of new design solutions. Whether explicitly - as in the case of Le Corbusier, James Stirling and Jo Coenen - or implicitly - as with J.J.P. Oud, Aldo van Eyk, and Santiago Calatrava - this practice has led to very advantageous efficient, effective, and innovative results. The goal of this research project is to contribute to the construction of computational tools to facilitate this practice by developing a model that grasps significant characteristics of the design process as it employs precedents. The model is built drawing an analogy from the natural evolution. The intention is not to represent the processes that take place in the architects minds but rather their behavior as this is manifested in their design products. The project draws from the multidisciplinary methodology of design tool development of the Design Knowledge Systems Research Center. It employs an analogy with Darwinian evolutionary theory in combination with recent theories of genetics and embryology. The criteria of usefulness in picturing the phenomenon in architecture determines the focus on particular aspects of the analogy. The research also uses three case studies from the architectural domain: J.J.P. Oud, to identify adequacy criteria for the model; Le Corbusier, to illustrate the components and conduct of the model under development; and Santiago Calatrava, to test the model. The research develops a pre-computational qualitative model that provides insights into the process of re-use and adequacy criteria for an analytical model to succeed in architectural practice. Given the notorious history of misuse of analogies from the Darwinian model and biological models in general to other fields, special attention was paid to circumscribe the limits of the analogy. There are basic differences between design and evolutionary models, the most important being the process of selection, natural versus artificial. As "breeders", designers recall from memory and/or from archives through "artificial selection" - this is not the case in natural selection. In natural evolution, mutations are "random", and natural selection gives the direction. In the human design process, mutations and selection are mostly intentional. Many analogies suffer from confusion between the natural science notion of evolution and the cultural notion of progress; they are also highly reductive in their representation of cognitive processes of design, misrepresenting the design process. The evolutionary and genetics analogy serve as heuristic devices to represent the mechanisms in the process of use and adaptation of design precedents and the elements of such precedents accumulated over the years that are adapted and recombined during the design process often leading to design innovations. The model employs the notion of "design feature", a precedent component, as the most important unit of selection. Drawing from developmental genetics, and the idea of regulatory genes, each feature is derived from two interlinked kind of instructions where the "regulatory d-gene" deals with the configurational instructions and the "structural d-gene" deals with the technique and materials used. In the design model, just as in evolution, the notion of fitting environmental constraints in the generation of form is essential. Fitness relates to both internal and external constraints; it is multi-dimensional in a multi-criteria ecological environment.