1,721,007 research outputs found
Structural comparison of three methods of manufacture for UAV wing
No full textThe application of Unmanned Aerial Vehicles (UAVs) has been around since the early 1900s, mainly in the application of war-faring where the most technological advancements have been made. With the rise of different platforms UAVs can offer such as aerial photography, data collection, humanitarian aid and disaster reliefs; it meant that anyone would find UAVs useful. Coupled with the exponential rise of Additive Manufacturing (AM) such as 3D printing, designing and fabricating UAV structure have never been easier and quicker. AM application in UAV platform have achieved feats in production time and material weight savings where structural and design optimization research have been put in place. Mathematical analysis such as Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD) are utilized to optimize the performance, design and structural integrity of the aircraft.
In this report, the author would be comparing the designs of a conventional manufactured UAV wing against two other AM UAV wings in terms of their structural integrity. The methodology of this report is to have a predetermined wing profile dimension with different structural designs of the ribs, strut, spar and stringers of the wing based on conventional and AM methods of fabrication. CFD analysis would be used to find out the loading conditions of the UAV to aid in the calculation of FEA structural analysis. Topology optimization would be used in the latter stages for weight reduction of the wing in the event of the wing failing in the simulation stages.Bachelor of Engineering (Mechanical Engineering
Development of longitudinal flight simulator
No full textIn this report, the construction and testing an open-loop longitudinal flight simulator are discussed. The core simulation engine is built in Simulink and the input are attitudes of the aircraft model in wind tunnel and the forces experienced by the aircraft model in inertial frame of reference. Integrating process between the Simulink model, the sensors used to obtain airplane model status and the actuators in the airplane model are covered.
Two different aircraft models are developed to test the simulator. First model is modified from a glider bought off-the-shelf, additional control surface are added to make it fully actuated and the model is fixed on top of the force sensor by a rod and a spherical bearing so that the translational motions are constrained while rotation is free in 3 DoF (pitch, roll, and yaw). Second model is build using wood rod as fuselage and NACA 2412 as the airfoil of a foam wing. The motion of the model is restricted to pitch only by a ball bearing attached at the CG location of the plane. And elevator in the tail is the only one control surface created for the model.
Limitation of the simulator is discovered through simulation experiment using first model, the horizontal forces transferred through a rod is not accurate and the flow condition required by the simulator cannot be satisfied. In the simulation of second model, only longitudinal motions are simulated and a method to synchronize the control and simulation results is discussed. XFLR analysis for the aircraft model is carried out to obtain the drag and lift produced in the simulated environment. Elevator control for maneuvers such as controlled climbing and climbing and descending to the same level is loaded to an Arduino Mega which act as controller of the aircraft and the control is implemented during simulation. The simulated trajectory fits the intended trajectory, and the simulation results also reflects some of the aerodynamic characteristics. Future work that can be done to improve the simulator is also discussed.Bachelor of Engineering (Aerospace Engineering
Sound Scattering from Acoustically Treated Bodies Using a Domain Decomposition Technique
No full textComparison of CFD with BEM Technique for Wind Turbine Simulation of Thin and Thick Rotor Blades
No full textExperimental Verification of Pitch Angles for Power Regulation of Variable Pitch Horizontal Axis Wind Turbine
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Design of vertical take-off landing quadplane
No full textThe popularity of Unmanned Aerial Vehicles (UAV) has been increasing rapidly over the past
few years and are now commercially available for anyone from amateurs to professional to
purchase and fly it straight out of the box. Over the years, multiple variants and designs of UAVs
have emerged in the market – from the Vertical Take-off and Landing (VTOL) types to fixedwing
aircrafts and hybrid-VTOL aircraft which are capable of VTOL and horizontal flight using
its fixed wing for lift instead of relying on the propellers. Whilst these new designs and
configurations continue to emerge in the market from time to time, developers and researchers
have been trying to improve the capabilities and efficiency of the UAV.
The limitations of UAVs come mainly from the battery capacity and the physical weight of the
UAV itself. Hence, it is imperative that the UAV should only carry weights that are necessary
for its flight. The typical VTOL fixed-wing UAV utilises four motors for its vertical take-off and
landing phase and a separate tail-mounted motor for the forward flight phase, both of which are
redundant when in the forward flight phase and VTOL phase respectively.
This final year project looks into designing and implementation of the tilt mechanism using 3D
printing for a fixed-wing hybrid-VTOL quadplane for the transition from a vertical hover to
forward flight and vice versa. The tilt mechanism allows for a more efficient flight as it eliminates
the dead-weight of having a tail-mounted motor that is used solely for forward flight as well as
the reduction of drag from a windmilling rotor in flight. The report also highlights the limitations
of the current design and suggests improvements that could be used in future hybrid-VTOL
design UAVs.Bachelor of Engineering (Aerospace Engineering
Development of a multi-rotor VTOL UAV : computation of aerodynamics forces and moments using CFD
No full textA VTOL model aircraft is analysed using CFD code. The model was first conceptually designed
using a simplified design code XFLR5, and a full detailed assessment of the model is performed. Detailed mesh independence studies were performed and the results for longitudinal motion were obtained. Furthermore, the performance data (Power vs Velocity and Thrust vs Velocity) were deducted from steady level CFD analysis. The speed for minimum drag was also obtained from the CFD analysis. Results were also obtained for Cm vs α and results indicated that XFLR5 over predicted the location for the CG compared to the recommendation of CFD. A conclusion highlighting the recommendations made from CFD, and future work followed.Bachelor of Engineering (Aerospace Engineering
Design and development of an autonomous underwater vehicle
No full textComputational Fluid Dynamics (CFD) was used in this report to determine the hydrodynamic characteristics and operating points of an Autonomous Underwater Vehicle (AUV) design. The effect of thrusters was simulated using a momentum source term, and its effect was tested using two computational models, k-ω SST and Spalart-Allmaras. A water tunnel test was done to determine the effect of the thrusters used in the design of this AUV, Blue Robotics T200. The results obtained from the water tunnel test was combined with the drag results obtained from CFD to obtain the operating points of the AUV in all three directions.Bachelor of Engineering (Aerospace Engineering
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