Engineering Commons^™

Development Of Guidance, Navigation, And Control Systems For Multi-Spacecraft Assembly In Proximity Operations, Mohammed Ayman Atallah

Theses

This thesis presents the development of Guidance, Navigation, and Control (GNC) algorithms for multi-spacecraft assembly in proximity operations. A 3-DOF mathematical model of spacecraft relative translational motion is derived using the Euler-Lagrange method. Additionally, a 6-DOF mathematical model of spacecraft relative translational and rotational motion is derived using the twistor method, with consideration for the kinematic coupling effect. A new Linear Time-Invariant (LTI) model is developed based on the twistor model, which is utilized in the design of the GNC systems. Both LTI Model Predictive Control (MPC) and Linear Time-Varying (LTV) MPC algorithms are employed to develop Guidance and Control …

Experimental Study Of Central And Side Jet With And Without Chevron Nozzle Exit On Gas Turbine Leading Edge Jet Impingement Cooling, Ahmad Yousef Alqasrawi

Theses

This thesis presents a comprehensive investigation into the application of jet impingement cooling on turbines blade leading edge. Gas turbines are extensively utilized in power generation and aerospace industries, where efficient cooling techniques are crucial to enhance the performance and lifespan of turbine blades. The leading edge of a turbine blade is particularly vulnerable to high-temperature exposure and thermal stresses, making it an essential area for effective cooling strategies. Jet impingement cooling is one of the most effective cooling techniques mostly used in the leading edge of rotating and stationary blades. This study aims to explore the performance of jet …

Design And Fem Modelling Of Mems Capacitive Accelerometer And Gyroscope For Quadcopter/Uav Applications, Shaikha Rashid Alnaqbi

Theses

This study presents the design, simulation, and analysis of Micro Electromechanical Systems (MEMS) sensors, constituting the principal components of MEMS-based Inertial Measurement Units (IMUs). The main objective of the study is to design, simulate and analyze 3-axis capacitive accelerometer and 3-axis gyroscope. The MEMS-based capacitive accelerometers and gyroscope are analyzed using Ansys Workbench. Modal, Static Structural and harmonic analysis are used to obtain resonant frequencies, deformation/stress and profile of amplitude over a wide range of frequencies. Mechanical sensitivity analysis of the designed accelerometer and gyroscope is performed using the Finite Element Method (FEM). Analytical Equations are developed to calculate mechanical …

A Numerical Investigation Realizing The Flow Structure And Heat Transfer Performance Of The Potential Impinging Jets, Mohammed Sami Uddin Khan

Theses

The demand for improvement in the performance of gas turbines has led to the consideration of flows at increasingly high temperatures, but this introduces challenges in terms of maintaining their structural integrity and preventing overheating. To respond to these challenges, gas turbine manufacturers have turned to internal cooling, and jet impingement provides an effective solution for cooling the leading edge of the blades of gas turbines. In this study, the author numerically simulated the cooling performance of the leading edge of the blades of a gas turbine under constant heat flux by using five configurations of jet impingement: a steady …

Thermohydraulic Performance Of 3d Printed Metal Heat Exchanger With Zig-Zag Minichannels, Aysha Rashed Alshamsi

Theses

This work proposes using zig-zag minichannels in heat exchangers for enhancing its performance while operating under balanced (heat capacity ratio of unity) and unbalanced flow (heat capacity ratio of 0.5) conditions for counter flow and parallel flow configurations. The performance of the heat exchangers is quantified in terms of effectiveness and pressure drops and studies are done for hot fluid Reynolds number ranging from 50 to 1500. This work employs a numerical study to investigate the performance of the heat exchanger with zig-zag minichannels.
Simulation is carried out using Fluent module of Ansys Workbench. The model used for simulation consists …

Electrochemical Investigation Of Copperzirconium Based Metallic Glass Cu₅₁Zr₃₀Hf₁₄Ag₅, Tamim Mohammad Ahmad

Theses

This thesis is concerned with the electrochemical investigation of the copper-zirconium

based metallic glass Cu₅₁Zr₃₀Hf₁₄Ag₅. Studying the corrosion behavior of the novel melt-spun metallic glass ribbons contributes to further research on the possibility of building future bio-implants. The objectives of this thesis are to synthesize the metallic glass ribbons which are free from cytotoxic elements using melt spinning technique, verify their amorphous nature using X-ray diffraction method, study the corrosion behavior using Potentiodynamic polarization and Electrochemical Impedance Spectroscopy in different acidic, neutral and basic solutions, and finally examine the surface morphology of …