4,938 research outputs found

    Hydrodynamic study of a bow of a combatant hull

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    This thesis regards methods to study and improve the hydrodynamic performances of a ship. More specifically, the attention is focused on the ship's resistance and on modern methods used in the design process to reduce it and achieve the best design configuration. These are CFD analyses and optimization techniques. Each aspect related to this modern design process is described in detail. The original part of this thesis is the study and the optimization of the DTMB 5415 hydrodynamics

    Numerical, analytical, experimental study of fluid dynamic forces in seals

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    NASA/Lewis Research Center is sponsoring a program for providing computer codes for analyzing and designing turbomachinery seals for future aerospace and engine systems. The program is made up of three principal components: (1) the development of advanced three dimensional (3-D) computational fluid dynamics codes, (2) the production of simpler two dimensional (2-D) industrial codes, and (3) the development of a knowledge based system (KBS) that contains an expert system to assist in seal selection and design. The first task has been to concentrate on cylindrical geometries with straight, tapered, and stepped bores. Improvements have been made by adoption of a colocated grid formulation, incorporation of higher order, time accurate schemes for transient analysis and high order discretization schemes for spatial derivatives. This report describes the mathematical formulations and presents a variety of 2-D results, including labyrinth and brush seal flows. Extensions of 3-D are presently in progress

    Complete quantum-inspired framework for computational fluid dynamics

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    Computational fluid dynamics is both an active research field and a key tool for industrial applications. The central challenge is to simulate turbulent flows in complex geometries, a compute-power intensive task due to the large vector dimensions required by discretized meshes. Here, we propose a full-stack solver for incompressible fluids with memory and runtime scaling polylogarithmically in the mesh size. Our framework is based on matrix-product states, a powerful compressed representation of quantum states. It is complete in that it solves for flows around immersed objects of diverse geometries, with non-trivial boundary conditions, and can retrieve the solution directly from the compressed encoding, i.e. without ever passing through the expensive dense-vector representation. These developments provide a toolbox with potential for radically more efficient simulations of real-life fluid problems

    Optimization of Heat Sinks in a Range of Configurations.

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    In this study, different heatsink geometries used for electronic cooling are studied and compared to each other to determine the most efficient. The goal is to optimize heat transfer of the heat sinks studied in a range of configuration based on fin geometry. Heat sinks are thermal conductive material devices designed to absorb and disperse heat from high-temperature objects (e.g. Computer CPU). Common materials used in the manufacturing of heat sinks are aluminum and copper due to their relatively high thermal conductivity and lightweight [1]. Aluminum is used as the material for the heatsinks studied in this research project. To start, experimental results from a wind tunnel test conducted were compared to numerical results generated to establish a validation case. Best practices in running numerical simulations on heat sinks along with suitable models for simulating real-world conditions were determined and analyzed. The two main thermal performance-evaluating parameters used in this project are pressure drop (ΔP) and thermal resistance (R). Thirteen numerical CFD simulations were run on different heatsink fin extrusion geometries including the traditional rectangular plate, arc plate, radial plate, cross pin, draft pin, hexagonal pin, mixed shape pin fin, pin and plate, separated plate, airfoil plate, airfoil pin, rectangular pin, and square zig-zag plate heat sinks. It was observed that different fin geometries and dimensions affect the performance of heat sinks to varying extents. The square zig-zag plate heat sink from results obtained had the lowest thermal resistance of 0.25 K/W with the separated plate having the lowest pressure drop of 11.94 Pa. This information is relevant in the selection of fan type, size, and model of heat sink for electronics cooling. Also, another important conclusion drawn from this project is the existence of no definite correlation between the thermal resistance (R) and pressure drop (ΔP) parameters when evaluating heatsink performance
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