Mechanical Engineering Commons^™

Development Of An Improved Low-Order Model For Propeller-Wing Interactions, Joshua Taylor Goates

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For aircraft that have propellers mounted in front of the wings or tail, the prop wash produced by the propellers can have a strong influence on the aerodynamics of the aircraft. As the accelerated air from the propeller flows over the wings and tail, it can cause an alteration in the aerodynamic forces produced by those surfaces. Thus, an understanding of propeller-wing interactions is essential for the design and analysis of many aircraft.

There are multiple existing methods for analyzing the propeller-wing interactions. High order methods, such as wind tunnel testing or computational fluid dynamics, provide very accurate results but …

A Propeller Model Based On A Modern Numerical Lifting-Line Algorithm With An Iterative Semi-Free Wake Solver, Zachary S. Montgomery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A fundamental aerodynamic analysis technique for a single straight fixed wing has been expounded upon and turned into a modern technique that can analyze multiple wings of more realistic shapes common on aircraft. This modern technique is extended further to apply towards propellers. A method to overcome propeller analysis problems at low airspeeds is presented. This method is compared to more traditional propeller analysis techniques.

Aeroelastic Simulation Of Wind Turbines Using Free Vortex Methods And Strategies For Accelerating The Computation, Shujian Liu

Doctoral Dissertations

This dissertation integrated the free vortex method code Wake Induced Dynamics Simulator (WInDS), which was developed by Sebastian et al., into the open source and widely-used software FAST. A range of computational strategies including paral- lelization and Treecode algorithms are used to increase the computational efficiency of the software. Full aero-hydro-servo-elastic simulations with free vortex method are conducted, which focus on an in-depth study on the influence of the aeroelasticity of the wind turbine and platform motions on the unsteadiness of the aerodynamics, and the comparison of aeroelastic responses of two floating wind turbine concepts. This dissertation also applies long …

Propeller Design Requirements For Quadcopters Utilizing Variable Pitch Propellers, Ian R. Mcandrew, Elena Navarro, Ken Witcher

Publications

Unmanned aerial vehicles, UAV, has increases in the drastically in these past several years since their costs reduced. This research is based and built upon previous research presented in a conference. With the advent of commercial Quadcopters, four propeller systems, are used, being designed and used to operate the advantages of both flight and hovering. The basic design of their propeller blades has not evolved from the early days of manned flight when wooden fixed blades were used. In this paper that expands upon previous findings and discussions it explores the historical developments. Furthermore, how the expansion and reduction in …

Design Optimization Of A Non-Axisymmetric Endwall Contour For A High-Lift Low Pressure Turbine Blade, Jacob Allen Dickel

Browse all Theses and Dissertations

Various approaches have been used to shape the geometry at the junction of the endwall and the blade profile in high-lift low-pressure turbine passages in order to reduce the endwall losses. This thesis will detail the workflow to produce an optimized non-axisymmetric endwall contour design for a front-loaded high-lift research turbine profile. Validation of the workflow was performed and included a baseline planar and test contour case for a future optimization study. Endwall contours were defined using a series of Bezier curves across the passage to create a smooth surface. A parametric based approach was used to develop the test …

Measurement Of Unsteady Characteristics Of Endwall Vortices Using Surface-Mounted Hot-Film Sensors, Emma Michelle Veley

Browse all Theses and Dissertations

High-lift low-pressure turbine blades produce significant losses at the junction with the endwall. The losses are caused by several complex three-dimensional vortical flow structures, which interact with the blade suction surface boundary layer. This study investigates the unsteady characteristics of these endwall flow structures on a highly loaded research profile and the adjacent endwall using surface-mounted hot-film sensors. Experiments were conducted in a low-speed linear cascade wind tunnel. The front-loaded blade profile was subjected to three different inlet conditions, consisting of two turbulence levels, and three incoming boundary layer thicknesses. Multiple surface-mounted hot-film sensors were installed throughout the passage. This …

Design Of Shape-Conforming Nosecone For Optimal Fluid Flow From Transonic To Supersonic Range, Anna Tombazzi

Williams Honors College, Honors Research Projects

Modern flight vehicles, such as rockets, missiles, and airplanes, experience a force caused by forebody wave drag during the flight. This drag force is induced when the frontal point of each vehicle breaks the pressure wave during flight. Efforts to reduce this wave drag force to improve flight efficiency include modifying the nosecone profile of the flight vehicles to lower the drag force.

This project revolved around creating a design to make the transformation of nosecone shapes from a ¾ Parabolic profile to a ½ Power Series profile possible, mid-flight. Using a novel nosecone assembly, shape memory alloys (SMAs) and …