No description available.

The field of UAV systems is an active research area with potential for development and enhancement in various perspectives. This thesis investigates different issues related to the design, operation and control of UAV systems with a focus on the application side of each proposed solution where the implementation side and applicability of the proposed solutions are always considered with high priority. The thesis discusses unmodeled actuator dynamics and their effect on UAV systems when using feedback linearisation to linearize nonlinear models of UAVs. The analysis shows potential risk when implementing feedback linearisation and neglecting actuator dynamics even for first order actuator system. A solution algorithm of two stage feedback linearisation is proposed to handle actuator dynamics and linearize the main dynamics of the system. In the field of design and operation of UAVs, this thesis proposes a systematic design procedure for electric propulsion systems that are widely used in UAVs. The design procedure guides the designer step by step to achieve minimum propulsion system weight or maximum flight time or a trade off between the two factors from the supplied solution sets. On the navigation side, the thesis proposes a new indoor navigation system that is easy to implement and less costly compared with other indoor navigation systems. The proposed system can be classified under computer-vision based navigation systems, however, it needs less information and less computational capacity. The thesis also contributes to the structure design of UAV systems by producing a novel tri-rotor UAV platform. The proposed UAV is novel in structure and design and has a centralized control system that stabilizes and tracks both rotational and transitional motion of the vehicle simultaneously.

Using of wind energy belongs to one of the fastest developing segments in the power production from renewable resources, which also relates to new studies and development of different types of power stations and brings new ideas to small wind sources spheres too. Savonius rotor is included in these spheres as well. This thesis deals with a complete design, realization and trial measurement of single-step Savonius rotor model. Introduction part treats of basic division and rotor utilization. Design part includes the design as well rotor graphical documentation. In the following part there is data evaluation, which leads to comparison with theoretical calculations. The final part includes an examination of possible utilization of Savonius rotor for generation of electricity.

This thesis describes the experimental test results and computer simulation investigations which were conducted to verify the existing theory of skewed disk forced response predictions. The experimental tests were conducted on a horizontal flexible shaft rotor system supported in two hydrodynamic journal bearings. The computer simulations were conducted with a program that uses a matrix transfer method to get the desired solution. The agreement between experiment and simulation is very good for most skewed disk response characteristics. The influence of measurement errors and operation condition uncertainties are discussed.In the first part of this study, the dynamic behavior of experimental investigations focused on two different skewed disk designs which were mounted at midspan, 1/3 span and 2/3 span of the shaft. The two skewed disks were designed to allow a fine angle adjustment of the desired skew angle. The two designs are (a) the angle tiltable disk and (b) the couple unbalanced mass disk. The experimental results are shown to be close to the theoretical predictions of other authors.In the second part of this study, an existing computer program was used to simulate the experimental test rotor. The results give excellent qualitative agreement although there are some differences in quantitative analysis comparisons. The forced response characteristics of the computer simulation match the experimental results. It has been shown that by using the approximate linear skewed disk model, it is possible to get similar results to the experimental tests for similar disk skew conditions. / Master of Science

Rotors are a crucial component of VTOL(vertical take-off and landing) devices like unmanned aerial vehicles (UAVs) or helicopters, etc., By generating a rotational force, they create the necessary thrust to lift and maneuver the vehicle in the air. In recent years, there has been a growing emphasis on developing rotor designs that are more efficient and effective for eVTOL. This has led to the emergence of several unconventional swept rotor designs that can improve aerodynamic and aeroacoustic performance. The present thesis aims to investigate the impact of achieving a balanced sweep distribution across a rotor blade and how it affects aerodynamic performance. The study explores the potential benefits and drawbacks of unconventional swept rotor designs and compares their performance curves to traditional straight rotor designs. The investigation begins with an overview of rotor design criteria and literature on swept rotor designs. A comprehensive design and analysis of the aerodynamic performance of various rotor designs are conducted using NASA's OpenVSP and VSPAero, a low-fidelity solver that implements the Vortex lattice method. The results are then compared with wind tunnel experiments. Based on the load distribution analysis of multiple sweep designs, it is noted that swept rotors exhibit decreased performance at lower advance ratios. However, as the speed or advance ratio increases, the overall performance of swept rotors significantly improves. This conclusion is drawn from the load distribution data obtained for each blade of the rotors, and by comparing the figure of merit (FOM) of various designs. / Master of Science / Picture this: a sleek unmanned aerial vehicle (UAV) soaring through the air, its Propellers whirring efficiently and quietly. What makes this possible? The answer lies in the design of the rotors themselves. Rotors are critical components of UAVs, providing the necessary thrust to lift and maneuver the vehicle in the air. And with the growing demand for more efficient and effective eVTOLs (Vertical take-off and Landing) vehicles, unconventional swept rotor designs have emerged as game-changers in the industry. The present thesis delves into the impact and effects of Parametric swept designs on rotor aerodynamic performance. The study seeks to uncover the potential benefits and drawbacks of these designs and compare their performance curves to traditional straight rotor designs. The study starts by looking at how rotors are designed and what others have done with similar designs. Various rotor designs have been thoroughly examined in terms of their aerodynamic characteristics using NASA's OpenVSP and VSPaero, a low-fidelity solver that uses the Vortex lattice method. To verify the tools, this data are compared with wind tunnel tests. Due to its cheap computing cost, OpenVSP makes it possible to investigate these discoveries in an economical manner. According to the results, swept rotors perform better at higher speeds than conventional rotors.

Double rotor machines, appearing in versatile forms and configurations thanks to the great flexibility of having a pair of rotors, are seen in a number of applications. Double rotor machines show promising prospect in the application of advanced hybrid electric vehicle powertrains due to the requirement of dual electro-mechanical ports in such systems. Integrating these powertrain systems with double rotor machines not only brings design freedom of laying out components, but also reduces number of parts and thus improves compactness. The switched reluctance type double rotor machines, offering unique characteristics of having a simple structure and no permanent magnets, are strong candidates for high performance applications. In this thesis, a family of double rotor switched reluctance machine with segmented rotors is proposed and studied. Compared to double rotor switched reluctance machines with a more conventional structure, the proposed designs exhibit potentials of achieving higher compactness and performance. A prototype double rotor machine of the segmented rotor design is constructed and tested to benchmark an existing double rotor switched reluctance machine. The experiment results show that the proposed design is able to achieve the same output with similar or higher efficiency than the benchmark machine, while occupying only about 60% of overall volume. The double segmented rotor switched reluctance machine demonstrates to be a promising double rotor topology and is worth further research. / Thesis / Master of Applied Science (MASc)

No description available.

An experimental investigation of the wake of a low-speed axial-flow compressor rotor was conducted with and without the presence of steady inlet total pressure distortions. The steady three-dimensional rotor inlet flow was obtained by a five-hole pneumatic pressure probe, while the one-dimensional rotor exit data were obtained using a piggyback steady/unsteady total pressure probe in non-nulling mode. Both inlet and exit flow conditions were measured in the stationary frame of reference. Results indicate increases in wake thickness and magnitude of total pressure defect as blade loading increased into the distortion cycle. The wake suction side jet increased in width and magnitude as blade loading increased, which appears to be a response to flow blockage caused by the growing boundary layer on the blades. Based on one-dimensional exit total pressure conditions with respect to the distortion screen, the dynamic response of the intra-blade passage flow does not appear to be a function of blade loading, measurement span, or distortion intensity within the ranges tested. Unsteady one-dimensional rotor exit suction side jet width and magnitude varied a great deal within and outside of the distorted region, and were only moderately correlated to inlet flow conditions. Changes in the unsteady one-dimensional rotor wake width and magnitude were usually in phase with and strongly correlated to changes in the inlet flow conditions. / Master of Science

No description available.

A validation of parallel TURBO, an unsteady RANS turbomachinery solver, is performed for Rotor 35. Comparisons of the rotor's operational range for computational and experimental data as well as comparisons of its spanwise performance characteristics for a single blade passage provide depth to the validation and show a very favorable agreement. Further operational and performance comparisons against experiment are used for multiple blade passage simulations. Multiple blade passage simulations are shown to demonstrate noticable gains over the single blade passage simulation in solution accuracy against experiment. Also demonstrated are the asymmetric flow features that develop at the near stall operating condition for multiple blade passages. These single and multiple blade passage simulations are presented as groundwork for future research examining the effect of periodic boundary conditions on the growth of computational stall cells within a rotor or stage configuration.