Engineering Commons^™

Modeling Of Rotor Wake Vortex Dynamics And Interactions In Non-Homogenous Vertiport Environments, Garrison P. Shaw

Doctoral Dissertations and Master's Theses

The current research serves to analyze and study the effects ground forces can have on the thrust performance of a propeller in multiple different configurations. The current research utilizes an open source Computational Fluid Dynamics (CFD) software known as OpenFOAM to generate calculate and visualize these runs. The model used for this experiment is a hybrid model that employs both a Unsteady Reynolds-Averaged Navier-Stokes (URANS) and a detached eddy simulation using a hybrid Large Eddy Simulation (LES) via a KomegaSSTDDES model. This model serves to save computational time as well as allow for accurate results. The three cases run are …

Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, Spencer Moore

Doctoral Dissertations and Master's Theses

Wall modeled Large Eddy Simulation (LES) is an area of interest due to its ability to lower computational costs of LES simulation. Even with the application of wall models, LES still proves to have practicality issues when it comes to use in industry, due to the expertise, time, and computational resources required to get results. A case described by an axisymmetric transonic bump is explored utilizing the Embry-Riddle Aeronautical Universities in house unstructured finite volume multi-element CFD code, Eagle3D. Eagle3D, has been brought to the state of the art and validated against current research using this transonic bump case as …

Prediction & Active Control Of Multi-Rotor Noise, Samuel O. Afari

Doctoral Dissertations and Master's Theses

Significant developments have been made in designing and implementation of Advanced Air Mobility Vehicles (AAMV). However, wider applications in urban areas require addressing several challenges, such as safety and quietness. These vehicles differ from conventional helicopter in that they operate at a relatively lower Reynolds number. More chiefly, they operate with multiples of rotors, which may pose some issues aerodynamically, as well as acoustically. The aim of this research is to first investigate the various noise sources in multi-rotor systems. High-fidelity simulations of two in-line counter-rotating propellers in hover, and in forward flight conditions are performed. Near field flow and …

Experimental Characterization Of Additively Manufactured Multi-Feather Wingtip Devices, Patricio Garzon

Doctoral Dissertations and Master's Theses

Soaring birds have evolved to fly for long periods of time without flapping their wings. Inspired by the flight of these birds, the proposed thesis presents an experimental investigation focused on wingtip devices designed based on biomimicry. The overarching engineering objective was to reduce the induced drag as a means to improve the fuel efficiency via these experimental wingtips. An associated secondary objective was to establish a method for manufacturing complex structures suitable for wing tunnel testing. A manufacturing technique that involved using composite weaves to reinforce additively manufactured structures was developed. This technique has the potential to reduce manufacturing …

Influence Of Wing Planform Shape On The Effectiveness Of A Fixed-Slot, Yuan Zhao

Doctoral Dissertations and Master's Theses

This thesis report explores the effect of the Clark-Y wing geometry on lift and drag to use as a reference during aircraft design stage. The different characteristics investigated are fixed slot span, taper ratio, washout, and sweep angle. Plain wings, half slotted wings, and fully slotted wings were built in CATIA with an aspect ratio of 6 and different taper ratio, washout, and sweep angles. Using the CATIA models to generate the 3-D grids in Pointwise. All the simulations were tested in Ansys-Fluent under sea-level conditions with a Reynold number of 609000. The relationships between the aerodynamic characteristics and the …

Design And Flight-Path Simulation Of A Dynamic-Soaring Uav, Gladston Joseph

Doctoral Dissertations and Master's Theses

We address the development of a dynamic-soaring capable unmanned aerial vehicle (UAV) optimized for long-duration flight with no on-board power consumption. The UAV’s aerodynamic properties are captured with the integration of variable fidelity aerodynamic analyses. In addition to this, a 6 degree-of-freedom flight simulation environment is designed to include the effects of atmospheric wind conditions. A simple flight control system aids in the development of the dynamic soaring maneuver. A modular design paradigm is adopted for the aircraft dynamics model, which makes it conducive to use the same environment to simulate other aircraft models. Multiple wind-shear models are synthesized to …

Computational Investigation Of Perforated Plate Film Cooling Utilizing Conjugate Heat Transfer, Jonathan Sippel

Doctoral Dissertations and Master's Theses

The accuracy of modern state-of-practice computational fluid dynamics approaches in predicting the cooling effectiveness of a perforated plate film-cooling arrangement is evaluated in ANSYS Fluent. A numerical investigation is performed using the Reynolds Averaged Navier Stokes equations and compared to NASA Glenn’s available Turbulent Heat Flux 4 experimental measurements collected as a part of the Transformational Tools and Technologies Project. A multiphysics approach to model heat conduction through the solid geometry is shown to offer significant improvements in wall temperature and film effectiveness prediction accuracy over the standard adiabatic wall approach. Additionally, localized gradient-based grid adaption is analyzed using the …

Identification Of Wind-Induced Hazard Zones Impacting Uas Bridge Inspection, Jack J. Green, John Mott

International Journal of Aviation, Aeronautics, and Aerospace

Unmanned Aerial Systems (UAS) continue to grow in both popularity and utility within the national airspace system. The use of commercial UAS for civil inspection, specifically that of bridge structures, is becoming commonplace among practitioners and academics alike. The development of an integrated bridge-inspection hazard model provides a way for UAS operators to prepare for and respond to changing environmental conditions that could otherwise prevent a successful UAS flight. The interaction of wind-induced airflow with bridge surfaces creates an aerodynamic wake that can result in hazardous conditions for a UAS platform operating in close proximity. An analysis of this airflow …

Comparative Study On Performance Accuracy Of Three Probe And Five Probe Flow Analysers For Wind Tunnel Testing, Akhila Rupesh Ms, J V Muruga Lal Jeyan Dr

International Journal of Aviation, Aeronautics, and Aerospace

In the field of inviscid fluid flow studies, the theoretical concept has to be developed even more. In order to make it possible, it is very important to supplement the concepts with strong experimental results. While performing experimentation, various accepts of design can be determined with factors influencing the and also required modification can be recommended in a more systematic and economic manner. Also, the aim objective of the experiment is to extend the underlying theory and to produce new designs with improvements that can be great support to the advancement in technology. In experimental analysis, wind tunnels are used …

Design, Construction And Testing Of A 3-Component Force Balance For Educational Wind Tunnels In Undergraduate Aerodynamics, Milan Tomin, Marco Scipioni, Benjamin Gatti

Journal of Aviation/Aerospace Education & Research

This article is focused on providing detailed instructions on how to build and use a force balance for educational wind tunnels. The article’s objective is to encourage undergraduate students in underfunded programs to engage in the field of aerodynamics. The discussed force balance represents an affordable device that only requires basic components like Arduino board, a servo motor, and acrylic and aluminum as construction materials. A simple data collection example is included at the end of the article showing that this simple force balance can collect meaningful data about lift, drag, and moment coefficient of a tested airfoil.

Experimental And Computational Evaluation Of Five Hole Five Probe Flow Analyzer For Subsonic Wind Calibration, Akhila Rupesh Ms, J V Muruga Lal Jeyan Dr

International Journal of Aviation, Aeronautics, and Aerospace

It is very essential to predict the flow and its related parameters to understand real life fluid flow. The real-life fluid problems are studied with wind tunnels which gives very efficient results in practice. But in the case of wind tunnel studies flow angularities plays crucial role. Flow angularity determination includes measurement of static pressure, dynamic pressure and inflow angles. Flow prediction even hold a very strong hand in design process. Designing and testing being the foundation of any process industry, flow measurements and its related parameters have to be well evaluated. In such cases, wind tunnels play important role …

Comparison Of Flow Field In The Proximity Of A Single Planar & Wrap-Around Fin, Nayhel Sharma, Palak Saini, Hrishabh Chaudhary, Gurteg Nagi, Rakesh Kumar Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Abstract

This paper analyses the results of the computational analysis between a single planar and a wrap-around fin mounted on a semi-cylindrical body. A free-stream Computational Fluid Dynamics (CFD) model was simulated for both cases in the Mach 0.4-3.0M range at 0°Angle of attack, in which, the behavior of flow around the fin was investigated using a turbulence model of higher order discretization. The post-processing shows all the possible views of the flow dynamics around the fins, as well as the missile body. The aerodynamic drag and the rolling moment characteristics of the planar and the wrap-around fin have been …

Cognitive Loading, Affect Regulation And Aerodynamic Considerations In Uninhabited Aerial Vehicle Systems Refueling Operations, Sam Holley, Ian R. Mcandrew

Publications

Factors influencing aerodynamics involved in aerial refueling illustrate the potential for specialist operators to manage these operations for remotely piloted vehicles. The authors review aerodynamic characteristics of uninhabited aerial systems during refueling, drogue and boom design and associated flight dynamics, cognitive factors associated with control transfer and refueling, and affective components and their influence on decision making and operator performance. Attention is directed to cognitive loading and encoding challenges, with considerations for hippocampal mapping and hemispheric asymmetry. Implications for system state awareness are examined. Advantages for specially trained refueling pilot operators are discussed and recommendations given for areas of concentration.

Lift & Drag Reductions On Iced Wings During Take Off And Landing With Unmanned Aerial Vehicles, Ian R. Mcandrew

Publications

This research paper addresses an novel problem that has not been addressed in detail for many decades. Ice formation on aircraft has procedures and protocols to deal with expected and actual problems. Complex modern aircraft are equipped with a variety of techniques to remove Ice formation on an aircraft, especially the wings. The introduction of Unmanned Aerial Vehicles has added an old problem, that of low speed and the lack of power to overcome losses in lift through ice formation. In this research the different types of Ice formation, how they combine and affect Lift and Drag are also addresses …

Book Review: High G Flight - Physiological Effects And Countermeasures, Stefan Kleinke

International Journal of Aviation, Aeronautics, and Aerospace

This review provides insight on the content and a review of the quality of the recent release of High G Flight - Physiological Effects and Countermeasures from Ashgate Publications.

This review does not reflect the views of IJAAA or ERAU. This work was not peer reviewed.

High G Flight - Physiological Effects and Countermeasures

Aerodynamic Forces On Flight Crew Helmets, Timothy A. Sestak, Richard M. Howard, Chester A. Heard

Publications

Wind tunnel tests were conducted to deter- mine the aerodynamic forces generated on aircrew flight helmets. Three helmets were tested: two used by aircrews flying ejection seat aircraft in the U.S. military, the Navy HGU-33/P and the Air Force HGU-53/P; and one prototype helmet of significantly different shape and volume. Axial and normal forces were measured through a range of pitch and yaw angles. It was found that large forces exist tending to promote helmet loss during ejection, and that simple modifications to the current helmet configurations can reduce those forces by as much as 40%. It is demonstrated that …