Dissertations / Theses on the topic 'Motor configurations'

The compound helicopter is a high speed design concept that is once again being explored due to the emerging requirements for rotorcraft to obtain speeds that significantly surpass the conventional helicopter. The speed of the conventional helicopter is limited by retreating blade stall, however the introduction of compounding delays the onset of this aerodynamic limitation until greater flight speeds. There are two common types of compounding known as lift and thrust compounding. Lift compounding, provided by the addition of a wing offloads the main rotor of its lifting responsibilities in high speed flight. Thrust compounding, provided by the addition of a propulsive source such as a propeller, provides additional axial force divorcing the main rotor of its propulsive duties at high speeds. The addition of compounding to the helicopter design can therefore increase the maximum speed of the aircraft. This increase in speed, provided that efficient hover capability is maintained, would make the compound helicopter suitable for various roles and missions in both military and civil markets. The compound helicopter is not a novel idea with many compound helicopter configurations flight tested in the 1960's. Due to these test programmes, as well as other studies, there is some material relating to the compound helicopter in the literature. However, the majority of the compound helicopter work describes flight tests of experimental aircraft or focuses on the design of the aircraft configuration. There are no systematic studies of the flight dynamics of compound helicopters which have been published. This Thesis targets this gap in the literature. Consequently, the aim of this Thesis is to investigate the effects of compounding on the conventional helicopter and how this addition to the helicopter design influences the flight mechanics of this aircraft class. With the renewed interest in the compound helicopter design this work is both original and timely. To investigate the flight dynamics of this aircraft class, two mathematical models of compound helicopter configurations are developed and compared with a conventional helicopter. The first compound helicopter configuration features a coaxial rotor with a pusher propeller providing additional axial thrust, and is referred to as the coaxial compound helicopter. The second configuration, known as the hybrid compound helicopter, features two wings each with a tip mounted propeller providing thrust compounding. The conventional helicopter features a standard helicopter design with a main rotor providing the propulsive and lifting forces, whereas a tail rotor, mounted at the rear of the aircraft, provides the yaw control. Other authors have focused on design considerations and have quantified all of the benefits of compounding but to date, a comprehensive study of the effect of compounding on the flight dynamics of a helicopter has not been published. The strategy of the work is to take the three aircraft configurations, the two compound helicopter configurations and the conventional helicopter, and determine their flight mechanics characteristics. Subsequently, the compound helicopter results can be compared with the baseline configuration, thereby isolating the effects of compounding. The flight mechanics characteristics that are determined in this Thesis include: trim, performance, stability and manoeuvrability attributes of the three helicopter configurations. These attributes are assessed by calculating the control angles which result in a steady flight condition and by the use of numerical linearisation and inverse simulation algorithms. All of these flight mechanics characteristics were assessed with the results, in some aspects, reinforcing the potential of the compound helicopter as well as highlighting some possible difficulties that will have to be addressed in the design of a compound helicopter.

[ES] El trabajo de investigación presentado en esta tesis es el resultado de varios años dedicados al desarrollo, la implementación y la optimización de dos tecnologías combinadas: un concepto de combustión innovador y una arquitectura de motor de nuevo diseño. Esta investigacion se ha realizado en el marco de una colaboración con Renault SA, como continuación de las actividades realizadas en el proyecto europeo POWERFUL (POWERtrain for FUture Light-duty vehicles) por un lado,y en el marco del proyecto europeo REWARD (Real World Advanced technologies foR Diesel engines), devenido como continuación del proyecto POWERFUL en el marco del programa de investigación Horizonte 2020, por otro lado. Los principales objetivos de estos estudios eran evaluar el potencial del concepto de combustión parcialmente premezclada (PPC) operando con gasolina como combustible en un innovador motor de 2 tiempos de válvulas en culata, y luego diseñar una nueva geometría de motor de 2 tiempos utilizando la arquitectura Uniflujo para superar los principales problemas y limitaciones observados durante la primera etapa, que se pueden resumir principalmente en el rendimiento de barrido (especialmente trabajando en cargas elevadas). La metodología diseñada para este trabajo de investigación sigue un enfoque teórico-experimental. La evaluación del concepto de combustión PPC operando con gasolina se llevó a cabo principalmente con un enfoque experimental con el apoyo del análisis en línea directamente en el banco de ensayo, seguido de un exhaustivo tratamiento posterior de los datos y de un análisis detallado del proceso de combustión utilizando herramientas de diagnóstico. Por el contrario, el desarrollo del nuevo motor Uniflujo de 2 tiempos consistió principalmente en iteraciones sobre modelado 3D-CFD, si bien las actividades experimentales fueron fundamentales para validar las diferentes soluciones propuestas y evaluar su sensibilidad ante diferentes parámetros de interés utilizando una metodología de Diseño de Experimentos (DoE). La primera parte del trabajo se ha dedicado a la comprensión de los procesos termodinámicos involucrados en la combustión operando con el concepto PPC en un motor de 2 tiempos de válvulas en culata utilizando gasolina como combustible, y a evaluar su potencial en términos de emisiones contaminantes, consumo de combustible y ruido. Por último, se ha realizado un trabajo de exploración para ampliar en la medida de lo posible el rango de funcionamiento de este concepto de combustión en esta configuración específica del motor, investigando especialmente el rendimiento en cargas bajas en todo el rango de regímenes de giro del motor, y estableciendo también las principales limitaciones para la operación en cargas altas. La segunda parte de la tesis se ha centrado en el desarrollo y optimización teórica de un motor Uniflujo de 2 tiempos de nuevo diseño, incluyendo su fabricación y validación experimental. El objetivo principal era optimizar, utilizando principalmente simulaciones 3D-CFD, el rendimiento de barrido de esta arquitectura de 2 tiempos mediante el diseño de nuevas geometrías de puertos de admisión, permitiendo un gran control sobre el flujo de aire hacia y a través del cilindro para barrer al máximo los gases quemados y minimizar el cortocircuito de aire fresco hacia el escape. Las soluciones óptimas se evaluaron experimentalmente siguiendo la metodología DoE, antes de comparar finalmente los resultados de rendimiento de barrido con la anterior arquitectura de motor de 2 tiempos con válvulas en culata.
[CA] El treball de recerca presentat en aquesta tesi és el resultat de diversos anys dedicats al desenvolupament, la implementació i l'optimització de dues tecnologies combinades: un concepte de combustió innovador i una arquitectura de motor de nou disseny. Aquesta recerca s'ha realitzat en el marc d'una col·laboració amb Renault SA, com a continuació de les activitats del projecte europeu *POWERFUL (*POWERtrain *for *FUture Light-*duty *vehicles) d'una banda, i en el marc del projecte europeu *REWARD (Real *World *Advanced *technologies *foR Dièsel *engines), es devingut com a continuació del projecte *POWERFUL en el marc del programa d'investigació Horitzó 2020, d'altra banda. Els principals objectius d'aquests estudis eren avaluar el potencial del concepte de combustió parcialment premesclada (PPC) operant amb gasolina com a combustible en un innovador motor de 2 temps de vàlvules en culata, i després dissenyar una nova geometria de motor de 2 temps utilitzant l'arquitectura Uniflux per a superar els principals problemes i limitacions observats durant la primera etapa, que es poden resumir principalment en el rendiment d'escombratge (especialment treballant en càrregues elevades). La metodologia dissenyada per a realitzar aquests treballs de recerca segueix un enfocament tant experimental com teòric. L'avaluació del concepte de combustió PPC operant amb gasolina es va dur a terme principalment amb un enfocament experimental, però sempre amb el suport de l'anàlisi en línia directament en el banc d'assaig, seguit d'un exhaustiu tractament posterior de les dades combinat amb una anàlisi detallada del procés de combustió utilitzant eines de diagnòstic. Per contra, el desenvolupament i el disseny del nou motor Uniflux de 2 temps va consistir principalment en iteracions sobre modelatge 3D-CFD, si bé les activitats experimentals van ser fonamentals per a validar les diferents solucions proposades i avaluar la seua sensibilitat davant una sèrie de paràmetres d'interés utilitzant una metodologia de Disseny d'Experiments (DoE). La primera part del treball s'ha dedicat a la comprensió dels processos termodinàmics involucrats en la combustió operant amb el concepte de combustió PPC en un motor de 2 temps de vàlvules en culata utilitzant gasolina com a combustible, i a avaluar el seu potencial en termes d'emissions contaminants, consum de combustible i també de soroll. Finalment, s'ha fet un treball d'exploració per a ampliar en la mesura que siga possible el rang de funcionament d'aquest concepte de combustió utilitzant eixa configuració específica del motor, investigant especialment el rendiment en càrregues baixes en tot el rang de règims de gir del motor, i establint també les principals limitacions per a l'operació en càrregues altes. La segona part de la tesi s'ha centrat en el desenvolupament i optimització teòrica d'un motor Uniflux de 2 temps de nou disseny, incloent la seua fabricació i validació experimental. L'objectiu principal era optimitzar, utilitzant principalment simulacions 3D-CFD, el rendiment d'escombratge d'aquesta arquitectura de 2 temps mitjançant el disseny de noves geometries de ports d'admissió, permetent un gran control sobre el flux d'aire cap a i a través del cilindre per a escombrar al màxim els gasos cremats i minimitzar el curtcircuit d'aire fresc cap a l'escapament. Les solucions òptimes es van fabricar i van avaluar experimentalment seguint la metodologia DoE, abans de comparar finalment els resultats de rendiment d'escombratge amb l'anterior arquitectura de motor de 2 temps amb vàlvules en culata.
[EN] The research work presented in this thesis is the result of several years dedicated to the development, implementation and optimization of two combined technologies: an innovative combustion concept and a newly designed engine architecture. These investigations have been performed in the framework of a research collaboration with Renault SA following up the activities performed along the European POWERFUL project (POWERtrain for FUture Light-duty vehicles) on the one hand, and in the framework of the European REWARD project (REal World Advanced technologies foR Diesel engines), brought as a continuation of the POWERFUL project in the frame of the Horizon 2020 research program, on the other hand. The main objectives of these studies were to evaluate the potential of the Partially Premixed Combustion (PPC) concept operating with gasoline fuel in an innovative 2-Stroke poppet-valve engine, and then to design a new 2-Stroke engine geometry using the Uniflow architecture to overcome the main problems and limitations observed during the first stage, which can be mainly summarized to the scavenging performance (especially at high loads). The methodology designed for performing these investigation is based on both experimental and theoretical approaches. The evaluation of the gasoline PPC concept was carried out mainly experimentally, but always supported by online analysis directly on the test-bench and followed by a thorough post-processing of the data combined with a detailed analysis of the combustion using combustion diagnostic tools. On the contrary, the development and design of the new 2-Stroke Uniflow engine consisted mainly of 3D-CFD iterations, but experimental testing was crucial to validate the different solutions proposed and evaluate their sensitivity to a set of parameters of interest using a Design of Experiments (DoE) methodology. The first part of the work has been dedicated to the understanding of the thermodynamical processes involved in the combustion in a poppet-valve 2-Stroke engine operating with the gasoline PPC concept, and to evaluate its potential in terms of pollutant emissions, fuel consumption and also noise. Finally, a wide exploration has been performed to extend as much as possible the operating range of this combustion concept using that specific engine configuration, especially investigating the low loads performance throughout the full range of engine speeds, and also laying out the main limitations for high-to-full load operations. The second part of the thesis has been focused on the development and theoretical optimization of a newly designed 2-Stroke Uniflow engine, leading to manufacture and experimental validation. The main objective was to optimize, using mainly 3D-CFD modeling simulations, the scavenging performance of this 2-Stroke architecture by designing new intake ports geometries and to enable a great control over the air flow into and through the cylinder in order to scavenge the burnt gases as much as possible while minimizing the fresh air short-circuit to the exhaust. The optimum solutions were then manufactured and experimentally tested following a DoE methodology, before finally comparing the results of the scavenging performance to the previous 2-Stroke poppet-valve engine architecture.
Thein, KJL. (2021). Evaluation of combustion concepts and scavenging configurations in a 2-Stroke compression-ignition engine for future automotive powerplants [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/164044
TESIS

This report is about the implementation of autonomy and control on a water quality measuring unmanned surface vehicle. The project was termed Catfish and involved five teams focusing on different aspects of the initial goal to create an autonomous three-part system; a surface drone, a submerged drone and flying drone. In this iteration of the Catfish project the focus laid on creating the surface drone and submerged drone as the Catfish project will improve over generations of thesis projects. The author of the report was in the Control and Autonomy team and had been tasked with giving the surface drone the autonomy needed to make this project viable. Existing advances made in autonomy was adopted and tested. With the help of estimation algorithms, and sensor fusion, a flight controller navigates the surface drone between a set of GPS waypoints. It is also able to counteract the external forces wind, waves and stream to keep its position. To reach this autonomy four test phases were conducted on a pre-prototype with progressively increased difficult autonomy starting with manual control and ending in advanced autonomy. When the advanced missions were executed the speed and accuracy of two different thruster configurations were examined and the best performing out of the two was implemented on the final prototype the other teams had designed. The project ended with a fully autonomous system that was able to execute all the navigational maneuvers required to operate autonomous water quality measuring missions.
Den här rapporten handlar om implementationen av autonomi och kontroll på en vattenkvalitetsmätande vattenburen drönare. Projektet fick namnet Catfish och blev indelat i fem teams som fokuserade på olika aspekter av ett 3-delsystem; en vattenburen, en undervattens och en flygande drönare. I denna iteration av Catfish projektet fokuserade medlemmarna på att utveckla den vattenburna och undervattens drönaren då projektet kommer fortsätta utvecklas under kommande generationer av Catfish projektrapporter. Författaren av den här rapporten ingick i ett team som hette "Control and Autonomy" och hade i uppgift att installera en autonom intelligens till den vattenburna drönaren för att göra Catfish prototypen användbar. Befintliga framsteg inom forskningsområdet blev granskade och testade. Genom att använda uppskattningsalgoritmer och "sensor fusion" lyckades en "flight controller" navigera drönaren mellan GPS waypoints och även behålla sin position genom att motverka krafterna från vind, vågor och strömmar. För att uppnå denna nivå av autonomi utför en förprototyp fyra test faser av ökad autonomisk svårhetsgrad. Under uppdraget blev hastigheten och precisionen av två olika motoruppsättningar undersöka och den som presterade bäst blev implementerad på den slutgiltig designen som de andra teamen hade utvecklat. Projektet avslutades med att ett fullt autonomt system blev utvecklat som var kapabel till att utföra alla navigationsmanövrar nödvändiga för att genomföra autonoma vattenkvalitetsmätningsuppdrag.

Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains x, 87 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-82).

Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains xiii, 164 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-87).

Cold-flow tests were conducted in mediums of air and water to investigate the internal flow field about the nozzle region of a proposed solid rocket motor (SRM) configuration that would potentially replace the current external boosters on NASA's Space Shuttle. One-eighth-scale clear acrylic models of the proposed submerged aft-dome and aft finned grain elements were constructed to simulate the aft segment of the SRM at ignition and 35 seconds into the firing sequence. Pressure, velocity, and turbulence profiles were obtained during cold air testing, while air bubbles and dye were used for flow visualization during water tunnel testing.

The flow visualization experiments indicated the presence of strong inlet vortices, alternating vortex shedding from both grain models' fins, circumferential flow in the aft-dome and around the nozzle, and recirculatory flow in the aft-dome and near an upstream portion of the 35-second grain model. Data acquired during cold air testing showed a turbulent low-velocity flow field in the aft-dome for both grain models. With respect to pressure and mean velocity virtually the entire nozzle/aft-dome region exhibited a minimal sensitivity to nozzle vectoring.

Master of Science

Non-planar wing configurations are often hypothesised as a means for improving the aerodynamic efficiency of large transport aircraft; C-wings may have the ability to exploit and unify drag reduction, aeroelasticity, and dynamics and control but their capacity to do so is ambiguous. The aim of this work is to provide an experimental demonstration with the aim of verifying the C-wing configuration’s potential application for drag and load alleviation. The successful application of a C-wing system for improving the aerodynamic efficiency depends upon the ability to construct the wing system such that a sufficiently low root bending moment and parasitic drag is maintained, relative to an equivalent planar wing system. This was facilitated by the development of a structured genetic algorithm (sGA) optimisation architecture capable of utilising fundamental aerodynamic theory, design specifications, and experimental facility constraints to provide non-arbitrary wing topology designs. The optimisation procedure aided in the design of a planar wing analogous of a typical mid-sized transport commercial aircraft wing topology, representing a 10% scale model. From this baseline design the sGA reconfigured the outboard 26% of the wing to independently form a C-wing topology, increasing the planforms aerodynamic efficiency by 74.5%. A modular wingtip semi-span model was designed to house the sGA planar and Cwing designs inside the University of Glasgow’s de Havilland wind tunnel for tests at Re = 1.5x10^6. A number of experimental techniques adopted, such as force/moment measurements, laser-Doppler vibrometry, PCB piezoelectric accelerometry, direct image correlation (DIC), surface flow visualizations, and stereoscopic particle image velocimetry (SPIV), provide insight into the semi-span model and wingtip arrangement structural dynamics and flow field physics. Aerodynamic performance metrics show that despite the C-wing operating with a 19.1% higher wing wetted area, a peak total drag reduction of 9.5% at a = 6^o is achieved in addition to a 1.1% reduction in the wing root bending moment for equivalent lift. Study of the near field wake indicated that this was achieved by the C-wing establishing a low vorticity spiral core vortex with accelerated vortex decay properties. The C-wing has also been found capable of passively attenuating buffet induced vibrations of the main-wing by up to 68.6%.

Rund 70 % der Energieaufnahme von elektrischen Antriebssystemen wird von quasistationären Antrieben in Transportanlagen hervorgerufen. Eine gesteigerte Energieeffizienz führt neben reduzierten Energiekosten zu weiteren Nutzeffekten, wie z.B. einem verringerten Kühlaufwand, einem kleinerem Bauraum und einer höheren Lebensdauer der Komponenten. Zur Steigerung der Energieeffizienz dieser Transportanlagen werden in dieser Arbeit Methoden zur Auslegung der zugehörigen Antriebssysteme unter besonderer Berücksichtigung des Förderprozesses erarbeitet. Als repräsentative Transportanwendungen werden Pumpen- und Förderbandanlagen untersucht. Dabei wird das gesamte elektromechanische System analysiert, um das volle Energiesparpotenzial zu erfassen – beginnend mit dem Lastprofil des transportierten Förderguts bis hin zur elektrischen Energieversorgung. Hierzu werden alle Systemkomponenten modelliert, um die Verluste in verschiedenen Betriebspunkten im Volllast- und Teillastbereich abzuschätzen. Darauf aufbauend erfolgt die Erarbeitung praktikabler Projektierungshinweise und prozessspezifischer Auswahldiagramme, welche eine schnelle Vorauswahl der energieeffizientesten Antriebstopologie ermöglichen. Da die Verlustmodelle auf frei zugänglichen Datenblattangaben basieren, können die vorgestellten Methoden und Auswahlkriterien bereits in einem frühen Projektierungsstadium zur Auslegung einer energieeffizienten Transportanlage angewandt werden.

碩士
義守大學
機械與自動化工程學系碩士班
98
An effort has been made to use Proportional-Integral-Derivative (PID) control technique and feedforward compensation to control robotic manipulators under a combined task of velocity and force. The control strategy is based on the assumption that the task surface is homogeneous. However, a non-homogeneous task surface with the frictional force being the only non-homogenous constraint is controllable using the scheme presented. A hybrid motor/wrench controller has been designed for manipulators. In the proposed scheme, a manipulator is put under hybrid control by controlling the voltage of each actuator, which modeled as a DC motor. The system includes two PID controllers to control the motor and wrench systems respectively. Dynamic forces are compensated by way the nonlinear feedback. Although a similar scheme to control position and force simultaneously was presented before, the current proposition enables the velocity and force to be controlled while the position is monitored at the same time. Because the dynamic force were considered in this scheme. It is believed the current scheme is more flexible and can achieve faster and more stable responses. In the following chapters of this study, different types of manipulator will be controlled by the hybrid controller to perform tasks under conditions of combined velocity and force. The proposed controller will control a planar 3R manipulator, a planar 3H manipulator, and the adaptive suspension vehicle in this work to demonstrate system responses and simulation results

碩士
國立成功大學
機械工程學系
89
There are various kinds of winding patterns for motors. However, there is a lack of research or documentation sorting such complex winding types and rules. Therefore, in this thesis, various kinds of winding configurations for an arbitrary 3-phase motor are discussed and sorted. In addition, taking a PM brushless motor as an example, an optimal design technique is therefore built based on Electromagnetics and Principles of Electric Machines. According to the winding rules, a total of three types of winding configurations for a commercial 3-phase motor with 9 slots and 8 poles (different from the one previously mentioned) are derived in this thesis. The analysis for the influence of these windings on motor performances under excitating different current and voltage sources is performed using a finite element software tool, the ANSOFT EM module. The results compare the effect of different winding patterns on torque ripple、torque、high efficiency range and velocity, which can be a reference for motor selection.

博士
國立成功大學
機械工程學系碩博士班
94
This work presents a systematic design methodology to integrate the configurations of electrical motors and gear transmission systems in conceptual design with defined graph representations. First, the existing electrical motors and gear transmissions are studied, and their characteristics of topological structures are concluded. According to the driving principle of the electrical motors, we redefine the relation between the primary and the secondary. As long as the primary keeps the same relative velocity with the secondary, the motor can still function. This concept is totally new in the design of electrical motors. A systematic approach for the configuration synthesis of all possible topological structures of integrated gear motors, gear dynamos, and plenary gear trains with concentric motors are proposed based on Yan’s methodology of creative mechanism design. As a result, the synthesized configurations of integrated gear motors are 36 with a three-link and 252 with a four-link gear train. The gear dynamos are 4 with a three-link and 26 with a four-link gear train. And, the synthesized five-link plenary gear trains integrated with concentric motors are 12. Prototypes of three-link and four-link gear motors and gear dynamos are designed, build, and tested. The results show that the proposed design concepts and systematic design methodology in this work are feasible.

碩士
國立成功大學
機械工程學系
87
This work presents an innovative concept, namely MOGEAR, by combining the design of (DC) motors and (gear) reducers. Existing DC motors and gear reducers are studied, and their characteristics are concluded. According to the driving principle of the DC motors, we redefine the relation between the stator and the rotor, i.e., the stator is not necessary to be fixed and the rotor is not necessary to be the output. As long as the stator keeps the same relative velocity with the rotor, the motor can still function. This concept is totally new in the design of DC motors. A systematic approach for the configuration synthesis of all possible topological structures of MOGEAR is proposed based on Yan''s methodology of creative mechanism design. As a result, we synthesize 22 configurations of MOGEAR with three-link gear reducers and 292 configurations of MOGEAR with four-link gear reducers. Two prototypes are designed, build, and tested. The results show that the innovative concept of MOGEAR first proposed in this work is feasible.

Rund 70 % der Energieaufnahme von elektrischen Antriebssystemen wird von quasistationären Antrieben in Transportanlagen hervorgerufen. Eine gesteigerte Energieeffizienz führt neben reduzierten Energiekosten zu weiteren Nutzeffekten, wie z.B. einem verringerten Kühlaufwand, einem kleinerem Bauraum und einer höheren Lebensdauer der Komponenten. Zur Steigerung der Energieeffizienz dieser Transportanlagen werden in dieser Arbeit Methoden zur Auslegung der zugehörigen Antriebssysteme unter besonderer Berücksichtigung des Förderprozesses erarbeitet. Als repräsentative Transportanwendungen werden Pumpen- und Förderbandanlagen untersucht. Dabei wird das gesamte elektromechanische System analysiert, um das volle Energiesparpotenzial zu erfassen – beginnend mit dem Lastprofil des transportierten Förderguts bis hin zur elektrischen Energieversorgung. Hierzu werden alle Systemkomponenten modelliert, um die Verluste in verschiedenen Betriebspunkten im Volllast- und Teillastbereich abzuschätzen. Darauf aufbauend erfolgt die Erarbeitung praktikabler Projektierungshinweise und prozessspezifischer Auswahldiagramme, welche eine schnelle Vorauswahl der energieeffizientesten Antriebstopologie ermöglichen. Da die Verlustmodelle auf frei zugänglichen Datenblattangaben basieren, können die vorgestellten Methoden und Auswahlkriterien bereits in einem frühen Projektierungsstadium zur Auslegung einer energieeffizienten Transportanlage angewandt werden.