Experimental Investigations into the Use of Piezoelectric Film Transducers to Determine Particle Size through Impact Analysis

Sensors are required to determine the particle size of granular materials in a variety of industries such as energy, chemical manufacturing and food processing. The importance of accurately monitoring the particle size is essential in quality control in these industrial sectors. This paper presents the use of a custom made piezoelectric PVDF film transducer that is capable of determining the particle size of granular material through impact analysis. Experiments were carried out using a purpose-built test rig using ball bearings of different sizes traveling at different velocities. Through power spectral analysis of the impact signal it has been determined that different components of the signal spectrum may relate to different characteristics of the particle itself such as particle impact velocity and particle size. A comparison between the experimental data and system modelling results using the known mechanical characteristics of the test particles shows close similarities

Development of Electrostatic and Piezoelectric Sensor Arrays for Determining the Velocity and Concentration Profiles and Size Distribution of Pneumatically Conveyed Bulk Solids

One way countries around the world are increasing the proportion of renewable fuels for electricity generation is to convert coal fired power stations to co-fired (biomass/coal fired) or converting coal fired power stations to burn only biomass fuels. This however has led to measurement challenges monitoring the complex multi-phase flow of the pulverised fuels entering the furnace due to the complex shape of biomass particles. To meet these measurement challenges a novel electrostatic sensor array and piezoelectric sensor array have been developed. The electrostatic sensor array consists of an array of electrostatic electrode pairs that span the diameter of the pipe. Consequently the electrostatic sensor array is capable of determining the particle velocity and concentration profiles as well as detecting specific flow regimes such as roping. The piezoelectric impact sensor array consists of an array of piezoelectric individual impact sensors that span the diameter of the pipe. The piezoelectric sensor array is capable of determining the particle concentration and size distribution profiles. Experimentation has been carried out on laboratory scale pneumatic conveying systems using a variety of materials such as coal, biomass, coal/biomass blends and plastic shot. Experiments using the electrostatic sensor array have shown that it is indeed capable of determining the particle velocity and concentration profiles in both dilute developed and undeveloped flows. Analysis of the standard deviation of the velocity profiles as well as the correlation coefficient profiles have indicated that parts of the pipe cross section have a more stable flow compared to others. Data obtained through on-line and off-line experimentation using the piezoelectric sensor array has shown that through selective frequency filtering of the impact signal particle size can be determined assuming the particle velocity and the mechanical properties of the conveyed pulverised materials are known. By using a threshold voltage to determine when an impact has occurred on each element of the piezoelectric sensor array the particle concentration profile has been determined. The concentration profiles measured by the piezoelectric sensor array were verified using the electrostatic sensor array

A photographic probe for wet steam

The work carried out during this engineering doctorate degree has led to significant advances in the application of photographic measurement techniques to the characterisation of coarse water in wet steam flow, with particular emphasis on the development of a compact measurement probe suitable for application in a low-pressure steam turbine. Through the application of pulsed LED illumination for the first time in a compact probe, photographs at high magnification with excellent resolution are obtainable at significantly shorter exposure times than others reported in the literature. This has the advantage of reducing motion blur enabling reliable quantitative analysis to take place. Secondary to this, the coupling of high magnification, high resolution photography with pulsed LED illumination has been shown to provide a powerful research tool for flow visualisation across a range of applications, at an order of magnitude lower cost than commercial solutions employing pulsed laser illumination for the same purpose. This builds on the work of others elsewhere in the literature, but again has been proven at shorter exposure times enabling higher magnification with reduced motion blur. Finally a flexible optical test rig has been designed and manufactured, to act as an experimental test-bed for both photographic and phase-Doppler measurements on two-phase steam and air-water sprays. Phase-Doppler anemometry measurements have been performed on an accelerated jet of two-phase steam in order to perform size and velocity measurement of liquid droplets. This acts as a proof-of-concept for the technique in wet steam given the appropriate optical access. In addition phase-Doppler measurements of an air-atomising water nozzle were used as a validation data set to assess the accuracy and reliability of quantitative data from the photographic probe. In this case quantitative data was extracted from the images through application of a custom-designed image processing algorithm, designed to extract droplet size and velocity information from double-exposure droplet images. In general agreement is good within 10-15% of the PDA measurements. Photographic and PDA measurements have also been taken of an LP spray nozzle, as used in the Alstom model steam turbine test facility. These tests have demonstrated significant differences in the spray characteristics when spraying into air and into vacuum conditions. This provides useful insight for the positioning and application of these spray nozzles in a steamturbine environmen

A photographic probe for wet steam

The work carried out during this engineering doctorate degree has led to significant advances in the application of photographic measurement techniques to the characterisation of coarse water in wet steam flow, with particular emphasis on the development of a compact measurement probe suitable for application in a low-pressure steam turbine. Through the application of pulsed LED illumination for the first time in a compact probe, photographs at high magnification with excellent resolution are obtainable at significantly shorter exposure times than others reported in the literature. This has the advantage of reducing motion blur enabling reliable quantitative analysis to take place. Secondary to this, the coupling of high magnification, high resolution photography with pulsed LED illumination has been shown to provide a powerful research tool for flow visualisation across a range of applications, at an order of magnitude lower cost than commercial solutions employing pulsed laser illumination for the same purpose. This builds on the work of others elsewhere in the literature, but again has been proven at shorter exposure times enabling higher magnification with reduced motion blur. Finally a flexible optical test rig has been designed and manufactured, to act as an experimental test-bed for both photographic and phase-Doppler measurements on two-phase steam and air-water sprays. Phase-Doppler anemometry measurements have been performed on an accelerated jet of two-phase steam in order to perform size and velocity measurement of liquid droplets. This acts as a proof-of-concept for the technique in wet steam given the appropriate optical access. In addition phase-Doppler measurements of an air-atomising water nozzle were used as a validation data set to assess the accuracy and reliability of quantitative data from the photographic probe. In this case quantitative data was extracted from the images through application of a custom-designed image processing algorithm, designed to extract droplet size and velocity information from double-exposure droplet images. In general agreement is good within 10-15% of the PDA measurements. Photographic and PDA measurements have also been taken of an LP spray nozzle, as used in the Alstom model steam turbine test facility. These tests have demonstrated significant differences in the spray characteristics when spraying into air and into vacuum conditions. This provides useful insight for the positioning and application of these spray nozzles in a steamturbine environmen

Proceedings of the 40th Aerospace Mechanisms Symposium

The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms. Organized by the Mechanisms Education Association, responsibility for hosting the AMS is shared by the National Aeronautics and Space Administration and Lockheed Martin Space Systems Company (LMSSC). Now in its 40th symposium, the AMS continues to be well attended, attracting participants from both the U.S. and abroad. The 40th AMS, hosted by the Kennedy Space Center (KSC) in Cocoa Beach, Florida, was held May 12, 13 and 14, 2010. During these three days, 38 papers were presented. Topics included gimbals and positioning mechanisms, CubeSats, actuators, Mars rovers, and Space Station mechanisms. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components. The use of trade names of manufacturers in this publication does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the National Aeronautics and Space Administratio

Digital fabrication of custom interactive objects with rich materials

As ubiquitous computing is becoming reality, people interact with an increasing number of computer interfaces embedded in physical objects. Today, interaction with those objects largely relies on integrated touchscreens. In contrast, humans are capable of rich interaction with physical objects and their materials through sensory feedback and dexterous manipulation skills. However, developing physical user interfaces that offer versatile interaction and leverage these capabilities is challenging. It requires novel technologies for prototyping interfaces with custom interactivity that support rich materials of everyday objects. Moreover, such technologies need to be accessible to empower a wide audience of researchers, makers, and users. This thesis investigates digital fabrication as a key technology to address these challenges. It contributes four novel design and fabrication approaches for interactive objects with rich materials. The contributions enable easy, accessible, and versatile design and fabrication of interactive objects with custom stretchability, input and output on complex geometries and diverse materials, tactile output on 3D-object geometries, and capabilities of changing their shape and material properties. Together, the contributions of this thesis advance the fields of digital fabrication, rapid prototyping, and ubiquitous computing towards the bigger goal of exploring interactive objects with rich materials as a new generation of physical interfaces.Computer werden zunehmend in Geräten integriert, mit welchen Menschen im Alltag interagieren. Heutzutage basiert diese Interaktion weitgehend auf Touchscreens. Im Kontrast dazu steht die reichhaltige Interaktion mit physischen Objekten und Materialien durch sensorisches Feedback und geschickte Manipulation. Interfaces zu entwerfen, die diese Fähigkeiten nutzen, ist allerdings problematisch. Hierfür sind Technologien zum Prototyping neuer Interfaces mit benutzerdefinierter Interaktivität und Kompatibilität mit vielfältigen Materialien erforderlich. Zudem sollten solche Technologien zugänglich sein, um ein breites Publikum zu erreichen. Diese Dissertation erforscht die digitale Fabrikation als Schlüsseltechnologie, um diese Probleme zu adressieren. Sie trägt vier neue Design- und Fabrikationsansätze für das Prototyping interaktiver Objekte mit reichhaltigen Materialien bei. Diese ermöglichen einfaches, zugängliches und vielseitiges Design und Fabrikation von interaktiven Objekten mit individueller Dehnbarkeit, Ein- und Ausgabe auf komplexen Geometrien und vielfältigen Materialien, taktiler Ausgabe auf 3D-Objektgeometrien und der Fähigkeit ihre Form und Materialeigenschaften zu ändern. Insgesamt trägt diese Dissertation zum Fortschritt der Bereiche der digitalen Fabrikation, des Rapid Prototyping und des Ubiquitous Computing in Richtung des größeren Ziels, der Exploration interaktiver Objekte mit reichhaltigen Materialien als eine neue Generation von physischen Interfaces, bei

EUROSENSORS XVII : book of abstracts

Fundação Calouste Gulbenkien (FCG).Fundação para a Ciência e a Tecnologia (FCT)

16th European Symposium on Comminution and Classification: book of extended abstracts

Extended abstracts from the 16th European Symposium on Comminution and Classification, ESCC 2019 held at the University of Leeds, 2-4 September 2019. Based on the abstracts received, the symposium was structured in the following themes: fundamentals of size reduction, innovations in milling and classification, nanomilling, mechano-chemistry and solid state transformations, pharmaceuticals and foods, attrition and wear, and related modelling. The notable number of abstracts received on modelling made it possible to divide them in sub-themes: mechanistic, population balance, discrete element and coupling with computational fluid dynamics

Volume 1 – Symposium

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group A: Materials Group B: System design & integration Group C: Novel system solutions Group D: Additive manufacturing Group E: Components Group F: Intelligent control Group G: Fluids Group H | K: Pumps Group I | L: Mobile applications Group J: Fundamental

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018