In preliminary building energy assessments, it is often desired to estimate a motor's input power. Motor power estimates in this context should be rapid, safe, and noninvasive. Existing methods for motor input power estimation, such as direct measurement (wattmeter), Current Method, and Slip Method were evaluated. If installed equipment displays input power or average current, then using such readings are preferred. If installed equipment does not display input power or current, the application of wattmeters or current clamps is too time-consuming and invasive for the preliminary energy audit. In that case, if a shaft speed measurement is readily available, then the Slip Method is a satisfactory method for estimating motor input power. An analysis of performance data for 459 motors suggests comparable performance for predicting normalized (to the nominal motor input power) motor input power with the Current and Slip Methods: 10.0% and 9.9% RMSE, respectively. Both of these methods may be improved by applying regression on the predicted variable and/or nameplate parameters. For example, the Slip Method could be improved by applying a second-order regression, thereby reducing the predicted load factor residual RMSE of the data set from 9.0% to 8.2%. The Current and Slip Methods were also evaluated on two real motors. The normalized (to the nominal motor input power) predicted input power RMSE for the Current Method was on average 15% for the two motors; for the Slip Method the corresponding average was 17.5%. In some cases, shaft speed measurements may not be available. A temperature-based approach for estimating motor input power was investigated. Other required parameters include ambient temperature, motor efficiency, and a motor thermal constant. The temperature approach offers quick, safe, and non-invasive motor power estimation. However, thermal coefficients may vary significantly across motors and a model to predict the thermal coefficients has yet to be developed. Furthermore, the temperature approach has a very strong dependence on motor efficiency uncertainty. Experiments were performed on two motors to determine their motor thermal constants. If a motor's thermal constants and running efficiency are known, then this method gave motor input power estimates with a RMSE (normalized to the nominal input power) on the order of 4% for the studied motors.

Most materials used in many industries such as plastic, food, pharmaceuticals, electronics, dye, etc. exhibit viscoelastic properties under their processing or flow conditions. Due to the elasticity of such materials, deformation-stress in addition to their hydrodynamic behavior differ from simple Newtonian fluids in many important respects. Rod climbing, siphoning, secondary flows are all common examples to how a viscoelastic fluid can exhibit quite distinctive flow behavior than a Newtonian fluid would do under similar flow conditions. In industrial processes involving flow of viscoelastic materials, understanding complexities associated with the viscoelasticity can lead to both design and development of hydrodynamically efficient processes and to improved quality of the final products. In the present study, the main objective is to develop two dimensional finite volume based convergent numerical algorithm for the simulation of viscoelastic flows using nonlinear differential constitutive equations. The constitutive models adopted are Oldroyd-B, Phan-Thien Tanner (PTT) and White-Metzner models. The semi-implicit method for the pressure-linked equation (SIMPLE) and SIMPLE consistent (SIMPLEC) are used to solve the coupled continuity, momentum and constitutive equations. Extra stress terms in momentum equations are solved by decoupled strategy. The schemes to approximate the convection terms in the momentum equations adopted are first order upwind, hybrid, power-law second order central differences and finally third order quadratic upstream interpolation for convective kinematics QUICK schemes. Upwind and QUICK schemes are used in the constitutive equations for the stresses. Non-uniform collocated grid system is employed to discretize flow geometries. As test cases, three problems are considered: flow in entrance of planar channel, stick-slip and lid driven cavity flow. Detailed investigation of the flow field is carried out in terms of velocity and stress fields. It is found that range of convergence of numerical solutions is very sensitive to the type of rheological model, Reynolds number and polymer contribution of viscosity as well as mesh refinement. Use of White-Metzner constitutive differential model gives smooth, non oscillatory solutions to much higher Weissenberg number than Oldroyd-B and PTT models. Differences between the behavior of Newtonian and viscoelastic fluids for lid-driven cavity, such as the normal stress effects and secondary eddy formations, are highlighted. In addition to the viscoelastic flow simulations, steady incompressible Newtonian flow of lid-driven cavity flow at high Reynolds numbers is also solved by finite volume approach. Effect of the solution procedure of pressure correction equation cycles, which is called inner loop, on the solution is discussesed in detail and results are compared with the available data in literature.

The research area is located to the northern tip of Tuzgolu fault zone in the junction of neotectonic structures, namely, EskiSehir-Cihanbeyli, Sungurlu-Kirikkale and Tuzg&ouml / l&uuml / fault zones (Central Anatolia). The study is carried out in Paleocene sequences of PaSadag group on the structural analysis of bed, gash vein, fault and fault plane slippage data. The method of study based on i) the rose and stereo analysis of the planar structure (beds, gash veins and faults) on ROCKWORKS 2009 software and ii) on fault slip analysis on ANGELIER 1979 software. The bed analyses done on 605 measurements manifest N10&deg / -20&deg / E bedding attitude. The analysis done on 64 gash veins shows a general trend of NNE-SSW (N15&deg / E). The final analysis done on 160 fault planes pointed out a general trend of NNWSSE (N20&deg / W). Analysis based on the fault plane slip data manifest two stages of faulting under almost NE-SW compression during post-Paleocene &ndash / pre-Miocene period and one stage of faulting under WNW-ESE extension most probably during post-Miocene. To conclude, the Paleocene sequences are deformed continuously under WNW-ESE directed compression which is followed by a NE-SW to N-S compression resulted in the development of a reverse to dextral strike slip faulting during post-Paleocene &ndash / pre-Miocene period.

There are many active and passive vibration control techniques to reduce the effect of energy on structures which emerges during an earthquake and reduce the displacement of buildings that is caused by ground acceleration. Main advantage of passive vibration control techniques over active vibration control techniques is / no external power or a sensor is required for passive vibration control devices (PVCDs) and it results in lower installation and maintenance costs. However, PVCDs require a predefined optimum damping ratio and optimum damping distribution along the structure since they are not adaptive to changing ground acceleration values. During the design of the PVCDs numerous factors such as building properties and earthquake characteristics should be considered. Dry friction damper is an example of PVCD and has an extensive usage in many different fields due to its high energy damping capacity with low cost and ease of installation. In this thesis, damping of seismic energy at buildings with dry friction dampers is investigated and a new optimization method is developed in frequency domain by employing Describing Function Method (DFM) which reduces the computational effort compared to the time domain and finite element solutions drastically. The accuracy and verification of the presented method is investigated by comparing the frequency domain results with time marching solutions. Furthermore, damper placement and slip forces on the dampers are optimized for single and multi-story buildings equipped with dry friction dampers by utilizing the developed method.

<p>This master’s degree project includes the construction, implementation and the theory of function of the traction control system NTRAC, a traction control system designed to increase performance. A closer functionality study of the more common safety-designed traction control systems has been executed. As a result of this study different techniques in decreasing engine torque has been concluded. NTRAC uses a fuel-cutting method to decrease the torque. The risks and consequences by this, as well as different solutions, are in detail discussed in the report.</p><p>One of the main design purposes with NTRAC was to be able to adapt it easily to different vehicles. To evaluate this ability NTRAC has been implemented into two test vehicles, most different to each other by means of physical measurements. As an outcome of this evaluation, a number of mathematical models have been derived and implemented in numerical MATLAB programs. Two models are explained in the report and are included in MATLABfiles as appendix three and four at the end of the report.</p><p>The first model describes the dependency between the action of decrease in torque and the relative remaining degree of efficiency and the report explains why this does not show a linear dependency. The friction between the tire and the road surface plays a crucial part in the theory behind traction control and the report describes in detail how traditional traction control systems are designed to make compromises, in wheel spin tolerances, and thus not uses the maximum amount of traction. To increase performance traction control systems continuously have to optimise this amount and also minimise its fluctuations. Wheels travel with different speeds when cornering, thus the traction control system has to compensate for this, and the second mathematical model in the report describes this in detail.</p><p>Finally an increase in performance is verified through the usage of NTRAC in the formula car KTHR2. During an international competition in the summer of 05, at Bounthingsthorp proving grounds, Leicestershire, England, under perfect weather conditions, a time-saving of nine percentage where registered at acceleration tests from 0 to 75 meters. </p>

Ο σκοπός της διατριβής αυτής είναι η γενίκευση και η μελέτη των προβλημάτων ελέγχου του δυαδικού οριακού στρώματος σε ένα γενικότερο πρόβλημα στο οποίο το μαγνητικό πεδίο και η έγχυση ξένου ρευστού συνυπάρχουν και αλληλεπιδρούν, ενώ ταυτόχρονα η ροή χαρακτηρίζεται ως ροή ολίσθησης, λόγω της αραίωσης του μέσου. / --

Recently, mostly due to global warming concerns and high oil prices, electric vehicles have attracted a great deal of interest as an elegant solution to environmental and energy problems. In addition to the fact that electric vehicles have no tailpipe emissions and are more efficient than internal combustion engine vehicles, they represent more versatile platforms on which to apply advanced motion control techniques, since motor torque and speed can be generated and controlled quickly and precisely. The chassis control systems developed today are distinguished by the way the individual subsystems work in order to provide vehicle stability and control. However, the optimum driving dynamics can only be achieved when the tire forces on all wheels and in all three directions can be influenced and controlled precisely. This level of control requires that the vehicle is equipped with various chassis control systems that are integrated and networked together. Drive-by-wire electric vehicles with in-wheel motors provide the ideal platform for developing the required control system in such a situation. The focus of this thesis is to develop effective control strategies to improve driving dynamics and safety based on the philosophy of individually monitoring and controlling the tire forces on each wheel. A two-passenger electric all-wheel-drive urban vehicle (AUTO21EV) with four direct-drive in-wheel motors and an active steering system is designed and developed in this work. Based on this platform, an advanced fuzzy slip control system, a genetic fuzzy yaw moment controller, an advanced torque vectoring controller, and a genetic fuzzy active steering controller are developed, and the performance and effectiveness of each is evaluated using some standard test maneuvers. Finally, these control systems are integrated with each other by taking advantage of the strengths of each chassis control system and by distributing the required control effort between the in-wheel motors and the active steering system. The performance and effectiveness of the integrated control approach is evaluated and compared to the individual stability control systems, again based on some predefined standard test maneuvers.

La fatigue à nombre de cycles élevé (HCF) est un mode de défaillance courant et dangereux pour les aubages de turbomachines. Elle est induite par les efforts dynamiques élevés générés lors de résonances présentes dans la plage de fonctionnement de ces machines. Les dispositifs amortisseurs basés sur l'utilisation du frottement sec, tels que les nageoires ou les frotteurs sous-plateformes, permettent de réduire les amplitudes vibratoires, voire de repousser les fréquences de résonance hors des zones de fonctionnement. Cependant la conception de ces dispositifs reste encore largement basée sur l'empirisme et ils peuvent être la source d'un effet de désaccordage potentiellement nuisible. L'objectif ici est de développer des modélisations adaptées au traitement du problème de vibration des aubages en présence de frottement sec, ceci afin de mieux maîtriser les comportements physiques mis en jeu et donc, de mieux maîtriser leur processus de conception. Plusieurs modélisations numériques sont testées et confrontées à des résultats de référence. Une comparaison entre procédures de résolution temporelle et fréquentielle est menée et montre l'efficacité des méthodes fréquentielles. La méthode fréquentielle de la balance harmonique à plusieurs harmoniques est adaptée au problème et exploitée dans le cadre d'une étude énergétique. Cette étude conduit à une meilleure compréhension des phénomènes mis en jeu lors de l'aplatissement des pics en fonctionnement ; elle permet de démontrer que l'alternance des états de contact glissant et bloqué est à l'origine de cet aplatissement et non la dissipation d'énergie comme souvent avancé dans la littérature. Enfin, la méthode est exploitée pour décrire le comportement des disques aubés désaccordés. La méthode de Monte Carlo est utilisée pour obtenir les caractéristiques statistiques de la réponse forcée d'un système discret, en tenant compte des variations stochastiques des paramètres du contact notamment, la charge normale, la raideur du contact et le coefficient de frottement. Les résultats obtenus permettent de mieux comprendre les effets de la nature variable de ces paramètres fondamentaux sur la dynamique d'ensemble du système non linéaire.

Baigiamajame darbe nagrinėjamos visureigio automobilio dinaminės charakteristikos bei pagrindiniai jas lemiantys parametrai, ieškoma būdų šių parametrų pagerinimui. Taip pat darbe apžvelgiamos automobilį veikiančios jėgos, apžvelgiama automobilio masės bei įkrovos lygio įtaka automobilio dinamikai, priekabos įtaka automobilio stabilumui bei valdomumui. Atlikus eksperimentinius visureigio automobilio kėbulo svyravimų bandymus priklausomai nuo: priekabos įkrovos, kelio dangos, bei transporto priemonės ir transporto priemonių junginio greičio gauti rezultatai išanalizuoti ir palyginti tarpusavyje. Pateikiami skaitinius bandymų rezultatus atitinkantys grafikai. Išvadose apibendrinami tyrimo rezultatai. / This master thesis analysis dynamic characteristics of all – terrain vehicle, main parameters having impact on them, searches for ways to improve them. The paper also reviews the forces operating on the vehicle, reviews the impact of the vehicle’s weight and the level of load on the dynamics of the vehicle, the influence of a trailer on the stability and controllability of the vehicle. The results of the experimental tests of all – terrain vehicles body’s swinging were analyzed and compared. The charts depicting numeric results of tests are provided. The conclusions summarize the results of the research.

Baigiamajame magistro darbe atliekamas sklandytuvo atakos ir slydimo kampo matavimo metodų tyrimas. Pirmoje darbo dalyje apžvelgiami atakos kampo matuokliai: virvutė, pritvirtinta ant stiklinio gaubto, atakos – slydimo kampo matuoklis su vėjarodžiu ir Pitoto vamzdelio tipo daviklis. Davikliai palyginami, aprašomi jų privalumai ir trūkumai lyginant su kitais davikliais. Antroje dalyje aprašomi alfa ir beta kampų matavimo metodai: matavimas vamzdelio tipo davikliu ir metodas, kai nenaudojami specialūs atakos, slydimo kampo davikliai. Toliau apžvelgiami veiksniai, turintys įtakos matavimo tikslumui. Pateikiamos kelių vamzdelio tipo daviklių kalibravimo kreivės. Paskutinėje dalyje programa Matlab kuriamas matematinis-dinaminis sklandytuvo modelis. Modeliu, pagal nustatytas sąlygas, skaičiuojami atakos ir slydimo kampai, analizuojami grafikai. / The thesis made the glider’s attack and slip angle measurement methods for the investigation. The first part gives an overview of measuring devices of angle of attack and slip angle: The side string, attached to the side of the canopy, vane mounted AOA sensor, Pitot-tube type sensor. The sensors are compared, describes their advantages and disadvantages compared with other sensors. The second part describes the alpha and beta angle measurement methods: measurement with the tube-type sensor, and the method without using the specific attack, slip angle sensors. The following gives an overview of factors affecting the measurement accuracy. Several tube-type sensor calibration curves are presented. The last part of thesis presents development of mathematical – dynamic model of the glider using Matlab software. The model calculates the angle of attack and slip using set conditions of flight.