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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Characterization of a Test Stand for Evaluating Performance and Qualifying Metal Media Filters under ASME AG-1

Wilson, John Andrew 14 December 2013 (has links)
The Institute of Clean Energy Technology (ICET) at Mississippi State University was awarded a contract by the DOE to design, fabricate, assemble, and characterize a research grade test stand to assist in the development of ASME AG-1 Section FI Metal Media Filters. The major barriers to completing the code section is development of a test stand for collecting data necessary to specify performance requirements for use and for filter qualification. Currently there is not a test stand capable of performing this testing. Performance criteria for the FI test stand were developed by the Section FI project team and ICET. These performance criteria were used to create a test stand to collect the data necessary to get Section FI balloted and approved.
12

Experimental Review of Methods for Performance Enhancement of Paraffin Fueled Hybrid Rocket Motors

Clay, Reed 09 August 2019 (has links)
While paraffin has the potential to be a high performance fuel for hybrid rockets, sloughing-off of portions of the fuel during the burn, fuel-liner delamination during fabrication, difficult ignition, and the escape of significant amounts of unburned paraffin droplets from the combustion chamber have hindered efforts to demonstrate superior performance in paraffinueled hybrid motors. This work investigates several methods for enhancing the performance of paraffin-based hybrid motors including the use of anti-sloughing baffles in the grain liner, ignition media to ensure repeatable and prompt engine start, improved methods for fuel grain production, and aluminum and potassium nitrate additives. The results of the tests demonstrate modest improvements in anti-sloughing and total impulse, compared to the baseline paraffin fuel grain. Difficulty achieving sufficiently repeatable results with the available commercial motor prevented some of the research goals from being completed but lead to a better understanding of the factors affecting the performance space.
13

Laboratory Test Set-up to Evaluate Electromechanical Actuation System for Aircraft Flight Control

Barnett, Street 03 June 2015 (has links)
No description available.
14

Evaluation of Novel and Low-Cost Materials for Bipolar Plates in PEM Fuel Cells

Desrosiers, Kevin Campbell 30 September 2002 (has links)
Bipolar plate material and fabrication costs make up a significant fraction of the total cost in a polymer electrolyte membrane fuel cell stack. In an attempt to reduce these costs, a novel manufacturing method was developed for use with composite materials. Conductive fillers were mixed with a polypropylene binder and molded into single cell monopolar plates. A fuel cell test stand, capable of testing six cells simultaneously, was used for long-term corrosion testing. In-situ tests took place in 5 cm2 active area fuel cells with cathode humidification. Using data from test cells containing graphite monopolar plates as a baseline, two composite formulations, were able to produce power at 66-79% of the baseline power. Power output from one cell remained in this range for over 200 hours, while the other sample experienced surface oxidation and eventually failed. With improvements in part conductivity coming from conductive polymers, this manufacturing technique holds the promise of producing monopolar and bipolar plates that could eventually be scaled up for use in fuel cell stacks. / Master of Science
15

Konstruktion av mekanisk anordning för utförande av test- och övningsflyg på en kvadrokopter

Nioti, Antonia Eugenia January 2016 (has links)
Testning av flygkontroller på en verklig kvadrokopter är en farlig och utmanande process eftersom kvadrokoptern kan krascha om flygkontrollern inte fungerar eller ifall operatören saknar flygerfarenheter. Den nuvarande lösningen är att montera kvadrokoptern i en mekanisk anordning som möjliggör testning av flygkontroller i säkra miljöer. Problemet med de befintliga testanordningarna är att de inte kan ge realistiska simuleringsförhållanden eftersom de i viss mån påverkar kvadrokopterns rörelse med följden att flygkontroller som utvecklas har begränsad grad av kontroll på kvadrokoptern. Syftet är att utforma en mekanisk anordning som ska ge möjlighet att både testa samt övningsflyga kvadrokoptern utan risk för personliga och materiella skador. Målet är att ta fram ritningar som ska kunna utgöra underlag för framtagning av en testprototyp. En litteraturstudie på befintliga testanordningar genomfördes som användes som underlag tillsammans med kvalitetshuset för att ta fram en kravspecifikation. Därefter genererades ett antal koncept som utvärderades med hjälp av beslutsmatris. Det valda konceptet modellerades sedan i CAD-programmet och utifrån den virtuella modellen konstruerades en verklig modell i trä som testades för att verifiera dess funktion. Resultatet är en fjäderbalanserad testanordning med sex frihetsgrader. Det är en konstruktion i aluminium innehållande en mekanisk arm som ger tre translationsfrihetsgrader, ett kulledsfäste som ger tre rotationsfrihetsgrader samt dragfjädrar för att tyngdkraftskompensera systemet. Testning av trä-modellen uppvisar att kvadrakoptern måste framföras i full fart för att styras tillsammans med armen eftersom friktionen mellan testanordningens leder är hög. Under förutsättning att friktionen mellan lederna kan hanteras verkar det att testanordningen uppfyller de ställda teoretiska förutsättningarna för att inte ha någon väsentlig påverkan på kvadrokoptern. Ändå kravs det kvalificerade tester innan något påstående att testanordningen inte påverkar kvadrokopterns rörelse och därmed kan ge realistiska flygsimuleringsförhållanden, ska kunna anges. / Testing of autonomous flight controllers on a real quadrocopter is a dangerous and challenging process because the quadrocopter can crash in case the flight controller does not function properly or in case the operator has no flight experience. The current solution is to mount the quadrocopter on a teststand, which allow the testing of flight controller in safe environments. The problem with the existing teststands is that they cannot provide realistic free flight conditions as they, to some extent, affect quadrocopter’s movement. Consequently, the developed flight controller is partially able to control the quadrocopter. The purpose with this study is to design a mechanical device for use in testing and learning to fly a quadrocopter without the risk of crashing the flying model or harming the people involved. The goal is to provide drawings for developing a test prototype.In order to understand the problem a literature review of previous test devices was carried out. The findings from the literature review were used in combination with Quality Function Deployment technique to create a House of Quality and thus develop a set of engineering specifications. After that, a number of concepts was generated and then evaluated by Pugh’s method. The selected concept was modeled in the CAD-software and based on the virtual model, a real model made of wood was constructed and tested in order to verify the function of the testbed. The final result is a spring-balanced test device with six degrees of freedom. It is a structure consisting of a mechanical arm providing three translational degrees of freedom, a swivel joint with three rotational degrees of freedom and a set of extension springs to achieve gravity balancing. The experimental results from the wooden model shows that the quadrocopter is required to fly at full speed in order for it to operate with the arm due to the high friction between the joints. Under the condition that the friction between the joints can be managed, the test device seems to fulfill the theoretical requirements for simulating free flight condition. Nevertheless, it requires specialized and advanced testing before any assertion that the test device does not affect the dynamics of quadrocopter and thus it can provide completely realistic flight conditions, can be made.
16

Konstrukční návrh zkušebního stavu s otevřenou smyčkou toku momentu pro experimentální ověření parametrů převodových ústrojí / Test Rig Design Proposal for the Experimental Validation of Transmission Parameters in Open Loop Torque Condition

Máca, Jiří January 2018 (has links)
This final diploma thesis deals with the issue of vibration and noise measurement of transmission devices. The research part describes the basic issues of noise and vibration generation, their measurement, as well as sources of vibrations in gear units. The practical part deals with the design proposal of the attachment of the experimental single-stage gearbox and the load dynamometer to the anechoic chamber including the drawings. Further, by checking the modal properties of the proposed test stand, using the finite element method, the analytical and numerical control of the torsional vibrations of the rotating parts with respect to the expected frequency ranges of use.
17

Návrh pracoviště pro zatěžování servopohonů / Design of test stand for servodrive loading

Gricman, Roman January 2019 (has links)
This master’s thesis is focused on a design of test stand for servodrives loading. The theoretical part analyses state of art of load testing systems and describes main parts of workplaces. In the practical part is design of mechanical construction of workplace and electrical parts of machine. Master’s thesis also includes verification of properties of mechanical assembly and safety functionality verification.
18

DESIGN AND COMMISSIONING OF A TEST STAND TO CONDUCT PERFORMANCE DEGRADATION STUDIES AND ACCELERATED LIFE TESTING ON WATER-COOLED VARIABLE-SPEED SCREW COMPRESSOR CHILLERS

Andreas Josef Hoess (12474678) 28 April 2022 (has links)
<p>  </p> <p>Environmental challenges, increasing energy costs and demand, and upcoming regulations (e.g., new equipment performance ratings, phase-down of HFCs) are a few of the main drivers behind the research on advanced HVAC&R equipment. The HVAC&R systems are one of the largest energy consumers in both commercial and residential buildings and their operation is essential to ensure thermal comfort as well as other industrial needs. Within this context, large chillers provide chilled water to condition commercial buildings and the new generation of smart chillers feature variable speed compressors that enable active capacity modulation. In turn, variable speed operation along with other factors can contribute to performance degradation. Understanding mechanisms of degradation and developing models that enable predicting the decrease in performance with respect to the rated values are still open topics in the literature. </p> <p>The overarching goal of this research is to investigate the performance degradation of a water-cooled variable-speed screw chiller under long term operation and to gain insights on the behavior of the chiller under accelerated life testing. In particular, this thesis covers the initial task of designing an experimental test setup that enables performance testing according to the AHRI 550/590 standard. Once the experimental setup was commissioned, a set of four standard-conform baseline tests was conducted to map the rated performance of the chiller at both full and part-load conditions. After completing the baseline tests, an accelerated life test cycle procedure was developed and implemented in order to conduct 24/7 automated testing on the chiller. To this end, two test modes were established to simulate a real-life use of the chiller and induce high level of thermo-mechanical stresses on the compressor. Furthermore, eight recurring baseline tests were conducted to determine the performance behavior after 1000 operating hours. Finally, a preliminary system model was set up. This thesis describes the design of the system, the commissioning and control and provides insights on the performance testing as well as long-term testing methodology and the modeling work that was done so far. </p>
19

Návrh zařízení pro testování atmosférických rezistorů / Design of stand for atmospheric resistors testing

Kerek, Milan January 2015 (has links)
This master’s thesis deals with the design and manufacture of device for testing and verification of functionality of atmospheric resistors produced by IMI CCI Czech Republic. An atmospheric resistor, also called disk stack, is a stack of disks through which the medium flows and the system of labyrinths in disk stack causing a pressure reduction of medium. This thesis describe design of the mechanical parts of stand for atmospheric resistors, choice pneumatic circuit’s components, data acquisition hardware for measuring flow, inlet and outlet pressure, and temperature. The software was created in LabVIEW programming environment. In the end of this paper was done measurement in order to test functionality of test stand and software.
20

Konstrukce experimentálního zařízení pro studium mazání okolků kolejových vozidel / Design of Wheel Flange Lubrication Experimental Apparatus

Nepovím, Radovan January 2012 (has links)
The diploma thesis deals with construction design and practical realisation of experimental apparatus for investigation of wheel flange track vehicle lubrication. Experimental apparatus in full-scale uses optical interferometry for investigation of lubrication behaviour in wheel flange contact. It is an innovative approach which has not been used for such experiments so far. The aim of the following measurement with this apparatus is to determine the minimal amount of ecological lubrication in wheel flange contact under certain conditions when there is no lubrication film interruption. The apparatus enables to measure real rail wear. This work contains the apparatus description for the study of wheel flange lubrication, wheel flange contact specifications, the description of its influence on wear and acoustic emission, and a detailed description of the experimental apparatus.

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