Free Liquid Drag−out from a Liquid Bath Using SPH

The liquid drag−out (LDO) coating process is a key process in metallic−coated strip production in continuous galvanising lines. The liquid is dragged−out by the strip when the strip pulls up from a bath. The liquid in the process is commonly liquid zinc. The LDO physical understanding is important to control the liquid film thickness, coated strip smoothness and production efficiency. The thesis aimed to understand free LDO fundamentals by developing a numerical tool to simulate the free LDO process. The LDO fundamentals (meniscus, stagnation point, re-circulation flow, boundary layer thickness) analysis are important, as the film is influenced by the fundamentals. A graphical processing unit (GPU) enables a Smoothed Particle Hydrodynamics (SPH) tool is to be developed using MATLAB. The SPH tool is validated against the numerical cases: lid−driven cavity, a hydrostatic tank under gravity and a droplet spreading on a solid surface. The inter−particle interaction (IIF) technique is used in modelling the surface tension and adhesion. Non−periodic inlet and outlet boundaries are present in LDO problem. Mirror buffer technique with SPH is implemented in the outlet to model the gradient−free Neumann boundary. Also, to conserve the domain mass over time, a novel approach is introduced to return the domain leaving particle immediately to the domain at the next time step

Virtual Reality Applied to Welder Training

Welding is a challenging, risky, and time-consuming profession. Recently, there has been a documented shortage of trained welders, and as a result, the market is pushing for an increase in the rate at which new professionals are trained. To address this growing demand, training institutions are exploring alternative methods to train future professionals with the goals of improving learner retention of information, shortening training periods, and lowering associated expenses. The emergence of virtual reality technologies has led to initiatives to explore their potential for welding training. Multiple studies have suggested that virtual reality training delivers comparable, or even superior, results when compared to more conventional approaches, with shorter training times and reduced costs in consumables. Additionally, virtual reality allows trainees to try out different approaches to their work. The primary goal of this dissertation is to develop a virtual reality welding simulator. To achieve this objective effectively, the creation of a classification system capable of identifying the simulator’s key characteristics becomes imperative. Therefore, the secondary objective of this thesis is to develop a classification system for the accurate evaluation and comparison of virtual reality welding simulators. Regarding the virtual reality welding simulation, the HTC VIVE Pro 2 virtual reality equipment was employed, to transfer the user’s action from the physical to the virtual world. Within this virtual environment, it was introduced a suite of welding tools and integrated a Smoothed Particle Hydrodynamics simulator to mimic the weld creation. After conducting comprehensive testing that revealed certain limitations in welding quality and in the simulator performance, the project opted to incorporate a Computational Fluid Dynamics (CFD) simulator. The development of the CFD simulator proved to be a formidable challenge, and regrettably, its complete implementation was unattainable. Nevertheless, the project delved into three distinct grid architectures, from these, the dynamic grid was ultimately implemented. It also proficiently integrated two crucial solvers for the Navier-Stokes equations. These functions were implemented in the Graphics Processing Unit (GPU), to improve their efficiency. Upon comparing GPU and Central Processing Unit (CPU) performance, the project highlighted the substantial computational advantages of GPUs and the advantages it brings to fluid simulations.A soldadura é uma profissão exigente, perigosa e que requer um grande investimento de tempo para alcançar resultados satisfatórios. Recentemente, tem sido registada uma falta de profissionais qualificados na área da soldadura. Como resultado, o mer cado está a pressionar para um aumento do ritmo a que os novos trabalhadores são formados. Para responder a esta crescente procura, as instituições de formação estão a explorar métodos alternativos para formar futuros profissionais, com o objetivo de melhorar a retenção de informação, encurtar os períodos de treino e reduzir as despe sas associadas. Com o desenvolvimento de tecnologias nas áreas de realidade virtual e realidade aumentada, têm surgido iniciativas para explorar o potencial destas na formação de soldadura. Vários estudos sugeriram que a formação em realidade virtual proporciona resultados comparáveis, ou mesmo superiores, aos de abordagens mais convencionais, com tempos de formação mais curtos e reduções nos custos de consumíveis. Além disso, a realidade virtual permite aos formandos experimentar diferentes abordagens ao seu trabalho. O objetivo principal desta dissertação é o desenvolvimento de um simulador de soldadura em realidade virtual. Para atingir este objetivo de forma eficaz, torna-se imperativa a criação de um sistema de classificação capaz de identificar as características chave do simulador. Assim, o objetivo secundário desta dissertação é desenvolver um sistema de classificação para a avaliação e comparação precisas de simuladores de soldadura em realidade virtual. Relativamente ao simulador de soldadura em realidade virtual, foi utilizado o kit de realidade virtual HTC VIVE Pro 2, para transferir as ações do utilizador no mundo físico para o mundo virtual. No ambiente virtual, foi introduzido um con junto de ferramentas de soldadura e integrado um simulador de Hidrodinâmica de Partículas Suavizadas para simular a criação da solda. Após a realização de testes exaustivos que revelaram algumas limitações na qualidade da solda e no desempenho do simulador, o projeto optou por incorporar um simulador de Dinâmica de Fluidos Computacional (CFD). O desenvolvimento do simulador CFD revelou-se um desa fio formidável e, infelizmente, não foi possível completar a sua implementação. No entanto, o projeto aprofundou três arquiteturas de grelha distintas, das quais foi implementada a grelha dinâmica. O projeto também implementou duas funções cru ciais para resolver as equações de Navier-Stokes. As funções relativas ao simulador de fluidos foram implementadas na Unidade de Processamento Gráfico (GPU), a fim de melhorar a sua eficiência. Ao comparar o desempenho da GPU com o da Unidade Central de Processamento (CPU), o projeto evidenciou os beneficios computacionais das GPUs e as vantagens que trazem para as simulações de fluidos

Machine learning model of acoustic signatures: towards digitalised thermal spray manufacturing.

Thermal spraying, an important industrial surface manufacturing process in sectors such as aerospace, energy and biomedical, remains a skill intensive process often involving multiple trial runs impacting the yield. The core research challenge in digitalisation of the thermal spraying process lies in instrumenting the manufacturing platform, as the process includes harsh conditions such as UV rays, high-plasma temperatures, dusty chemical environments and inaccessibility of the spray booth. This paper introduces a novel application of machine learning to the acoustic emission spectra of thermal spraying. By transitioning from the amplitude-time domain to a Fourier-transformed frequency-time domain, it is possible to predict anomalies in real-time - a crucial step towards sustainable material and manufacturing digitalisation. Our experimental results also indicate that this method is suitable for industrial applications, by generating useful data that can be used to develop Visual Geometry Group (VGG) transfer learning models to overcome the traditional limitations of convoluted neural networks (CNN)

Modern Ultra-Fast Detectors for Online Beam Diagnostics

Synchrotron light sources operate with bunch repetition rates in the MHz regime. The longitudinal and transverse beam dynamics of these electron bunches can be investigated and characterized by experiments employing linear array detectors. To improve the performance of modern beam diagnostics and overcome the limitations of commercially available detectors, we have at KIT developed KALYPSO, a detector system operating with an unprecedented frame rate of up to 12 MHz. To facilitate the integration in different experiments, a modular architecture has been utilized. Different semiconductor microstrip sensors based on Si, InGaAs, PbS, and PbSe can be connected to the custom-designed low noise front-end ASIC to optimize the quantum efficiency at different photon energies, ranging from near-UV, visible, and up to near-IR. The front-end electronics are integrated within a heterogeneous DAQ consisting of FPGAs and GPUs, which allows the implementation of real-time data processing. This detector is currently installed at KARA, European XFEL, FLASH, Soleil, DELTA. In this contribution, we present the detector architecture, the performance results, and the ongoing technical developments

Recent advances in modelling and simulation of surface integrity in machining - A review

Machining is one of the final steps in the manufacturing value chain, where the dimensional tolerances are fine-tuned, and the functional surfaces are generated. Many factors such as the process type, cutting parameters, tool geometry and wear can influence the surface integrity (SI) in machining. Being able to predict and monitor the influence of different parameters on surface integrity provides an opportunity to produce surfaces with predetermined properties. This paper presents an overview of the recent advances in computational and artificial intelligence methods for modelling and simulation of surface integrity in machining and the future research and development trends are highlighted

Recent advances in modelling and simulation of surface integrity in machining - A review

Machining is one of the final steps in the manufacturing value chain, where the dimensional tolerances are fine-tuned, and the functional surfaces are generated. Many factors such as the process type, cutting parameters, tool geometry and wear can influence the surface integrity (SI) in machining. Being able to predict and monitor the influence of different parameters on surface integrity provides an opportunity to produce surfaces with predetermined properties. This paper presents an overview of the recent advances in computational and artificial intelligence methods for modelling and simulation of surface integrity in machining and the future research and development trends are highlighted

Molecular Dynamics Simulation of Iron — A Review

published_or_final_versio

Towards Scalable Nanomanufacturing: Modeling The Interaction Of Charged Droplets From Electrospray Using Gpu

Electrospray is an atomization method subject to intense study recently due to its monodispersity and the wide size range of droplets it can produce, from nanometers to hundreds of micrometers. This thesis focuses on the numerical and theoretical modeling of the interaction of charged droplets from the single and multiplexed electrospray. We studied two typical scenarios: large area film depositions using multiplexed electrospray and fine pattern printings assisted by linear electrostatic quadrupole focusing. Due to the high computation power requirement in the unsteady n-body problem, graphical processing unit (GPU) which delivers 10 Tera flops in computation power is used to dramatically speed up the numerical simulation both efficiently and with low cost. For large area film deposition, both the spray profile and deposition number density are studied for different arrangements of electrospray and electrodes. Multiplexed electrospray with hexagonal nozzle configuration can not give us uniform deposition though it has the highest packing density. Uniform film deposition with variation \u3c 5% in thickness was observed with the linear nozzle configuration combined with relative motion between ES source and deposition substrate. For fine pattern printing, linear quadrupole is used to focus the droplets in the radial direction while maintaining a constant driving field at the axial direction. Simulation shows that the linear quadrupole can focus the droplets to a resolution of a few nanometers quickly when the interdroplet separation is larger than a certain value. Resolution began to deteriorate drastically when the inter-droplet separation is smaller than that value. This study will shed light on using electrospray as a scalable nanomanufacturing approach