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Description
This thesis uses an aircraft aerodynamic model and propulsion data, which

represents a configuration similar to the Airbus A320, to perform trade studies to understand the weight and configuration effects of “out-of-trim” flight during takeoff, cruise, initial approach, and balked landing. It is found that flying an aircraft slightly above the

This thesis uses an aircraft aerodynamic model and propulsion data, which

represents a configuration similar to the Airbus A320, to perform trade studies to understand the weight and configuration effects of “out-of-trim” flight during takeoff, cruise, initial approach, and balked landing. It is found that flying an aircraft slightly above the angle of attack or pitch angle required for a trimmed, stabilized flight will cause the aircraft to lose speed rapidly. This effect is most noticeable for lighter aircraft and when one engine is rendered inoperative. In the event of an engine failure, if the pilot does not pitch the nose of the aircraft down quickly, speed losses are significant and potentially lead to stalling the aircraft. Even when the risk of stalling the aircraft is small, the implications on aircraft climb performance, obstacle clearance, and acceleration distances can still become problematic if the aircraft is not flown properly. When the aircraft is slightly above the trimmed angle of attack, the response is shown to closely follow the classical phugoid response where the aircraft will trade speed and altitude in an oscillatory manner. However, when the pitch angle is slightly above the trimmed condition, the aircraft does not show this phugoid pattern but instead just loses speed until it reaches a new stabilized trajectory, never having speed and altitude oscillate. In this event, the way a pilot should respond to both events is different and may cause confusion in the cockpit.
ContributorsDelisle, Mathew Robert (Author) / Takahashi, Timothy (Thesis advisor) / White, Daniel (Committee member) / Niemczyk, Mary (Committee member) / Arizona State University (Publisher)
Created2018
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Description
This study identifies the influence that leading-edge shape has on the aerodynamic characteristics of a wing using surface far-field and near-field analysis. It examines if a wake survey is the appropriate means for measuring profile drag and induced drag. The paper unveils the differences between sharp leading-edge and blunt leading-edge

This study identifies the influence that leading-edge shape has on the aerodynamic characteristics of a wing using surface far-field and near-field analysis. It examines if a wake survey is the appropriate means for measuring profile drag and induced drag. The paper unveils the differences between sharp leading-edge and blunt leading-edge wings with the tools of pressure loop, chordwise pressure distribution, span load plots and with wake integral computations. The analysis was performed using Computational Fluid Dynamics (CFD), vortex lattice potential flow code (VORLAX), and a few wind-tunnels runs to acquire data for comparison. This study found that sharp leading-edge wings have less leading-edge suction and higher drag than blunt leading-edge wings.

The blunt leading-edge wings have less drag because the normal vector of the surface in the front section of the airfoil develops forces at opposed skin friction. The shape of the leading edge, in conjunction with the effect of viscosity, slightly alter the span load; both the magnitude of the lift and the transverse distribution. Another goal in this study is to verify the veracity of wake survey theory; the two different leading-edge shapes reveals the shortcoming of Mclean’s equation which is only applicable to blunt leading-edge wings.
ContributorsOu, Che Wei (Author) / Takahashi, Timothy (Thesis advisor) / Herrmann, Marcus (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2019
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Description
In previous work, the effects of power extraction for onboard electrical equipment and flight control systems were studied to determine which turbine shaft (i.e. high power shaft vs low power shaft) is best suited for power extraction. This thesis will look into an alternative option, a three-spool design with a

In previous work, the effects of power extraction for onboard electrical equipment and flight control systems were studied to determine which turbine shaft (i.e. high power shaft vs low power shaft) is best suited for power extraction. This thesis will look into an alternative option, a three-spool design with a high-pressure turbine, low-pressure turbine, and a turbine dedicated to driving the fan. One of the three-spool turbines is designed to be a vaneless counter-rotating turbine. The off-design performance of this new design will be compared to the traditional two-spool design to determine if the additional spool is a practical alternative to current designs for high shaft horsepower extraction requirements. Upon analysis, this thesis has shown that a three-spool engine with a vaneless counter-rotating stage has worse performance characteristics than traditional two-spool designs for UAV systems.
ContributorsBurgett, Luke Michael (Author) / Takahashi, Timothy (Thesis advisor) / Dahm, Werner (Committee member) / Trimble, Steve (Committee member) / Arizona State University (Publisher)
Created2019
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Description
The thesis is an investigation on current regulations of commercial aircraft landing and take-off procedures and an analysis of potential weaknesses within the regulatory system for commercial aerospace. To determine such flaws, an area of worse-case scenarios with regard to the aforementioned flight operations was researched. The events selected to

The thesis is an investigation on current regulations of commercial aircraft landing and take-off procedures and an analysis of potential weaknesses within the regulatory system for commercial aerospace. To determine such flaws, an area of worse-case scenarios with regard to the aforementioned flight operations was researched. The events selected to best-depict these scenarios where incidents of aircraft overrunning the runway, referred to as runway excursions. A case-study conducted of 44 federal investigations of runway excursions produced data indicating four influential factors within these incidents: weather, pilot error, instrument malfunction, and runway condition. Upon examination, all but pilot error appeared to have federal enforcement to diminish the occurrence of future incidents. This is a direct result of the broad possibilities that make up this factor. The study then searched for a consistent fault within the incidents with the results indicating an indirect relationship of thrust reversers, a technique utilized by pilots to provide additional braking, to these excursions. In cases of thrust reverser failure, pilots' over-reliance on the system lead to time being lost from the confusion produced by the malfunction, ultimately resulting in several different runway excursions. The legal implication with the situation is that current regulations are ambiguous on the subject of thrust reversers and thus do not properly model the usage of the technique. Thus, to observe the scope of danger this ambiguity presents to the industry, the relationship of the technique to commercial aerospace needed to be determined. Interviews were set-up with former commercial pilots to gather data related to the flight crew perspective. This data indicated that thrust reversers were actively utilized by pilots within the industry for landing operations. The problem with the current regulations was revealed that the lack of details on thrust reverser reflected a failure of regulations to model current industry flight operations. To improve safety within the industry, new data related to thrust reverser deployment must be developed and enforced to determine appropriate windows to utilize the technique, thus decreasing time lost in confusion that results from thrust reversers malfunction. Future work would be based on producing simulations to determine said data as well as proposing the policy suggestions produced by this thesis.
ContributorsCreighton, Andrew John (Author) / Takahashi, Timothy (Thesis director) / Marchant, Gary (Committee member) / Kimberly, Jimmy (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Politics and Global Studies (Contributor)
Created2014-05
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Description
This paper describes an aircraft design optimization tool for wave drag reduction. The tool synthesizes an aircraft wing and fuselage geometry using the Rhinoceros CAD program. It then implements an algorithm to perform area-ruling on the fuselage. The algorithm adjusts the cross-sectional area along the length of the fuselage, with

This paper describes an aircraft design optimization tool for wave drag reduction. The tool synthesizes an aircraft wing and fuselage geometry using the Rhinoceros CAD program. It then implements an algorithm to perform area-ruling on the fuselage. The algorithm adjusts the cross-sectional area along the length of the fuselage, with the wing geometry fixed, to match a Sears-Haack distribution. Following the optimization of the area, the tool collects geometric data for analysis using legacy performance tools. This analysis revealed that performing the optimization yielded an average reduction in wave drag of 25% across a variety of Mach numbers on two different starting geometries. The goal of this project is to integrate this optimization tool into a larger trade study tool as it will allow for higher fidelity modeling as well as large improvements in transonic and supersonic drag performance.
ContributorsLeader, Robert William (Author) / Takahashi, Timothy (Thesis director) / Middleton, James (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
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Description
This paper outlines the development of a script which utilizes a series of user-defined input parameters to construct base-level CAD models of aircraft landing gear. With an increased focus on computation development of aircraft models to allow for a rapidprototyping design process, this program seeks to allow designers to check

This paper outlines the development of a script which utilizes a series of user-defined input parameters to construct base-level CAD models of aircraft landing gear. With an increased focus on computation development of aircraft models to allow for a rapidprototyping design process, this program seeks to allow designers to check for the validity of design integration before moving forward on systems testing. With this script, users are able to visually analyze the landing gear configurations on an aircraft in both the gear up and gear down configuration. The primary purpose this serves is to determine the validity of the gear's potential to fit within the limited real estate on an aircraft body. This, theoretically, can save time by weeding out infeasible designs before moving forward with subsystem performance testing. The script, developed in Python, constructs CAD models of dual and dual-tandem main landing gear configurations in the CAD program Rhino5. With an included design template consisting of 33 parameters, the script allows for a reasonable trade off between conciseness and flexibility of design.
ContributorsPatrick, Noah Edward (Author) / Takahashi, Timothy (Thesis director) / Middleton, James (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more.

There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more. However, there are very limited ways to predict and calculate the minimum control speeds of an airplane in engine inoperative flight. There are simple solutions, as well as complicated solutions, yet there is neither standard technique nor consistency throughout the aerospace industry. To further complicate this subject, airplane designers have the option of using an Automatic Thrust Control System (ATCS), which directly alters the minimum control speeds of an airplane.

This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA.

This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part of the design of an airplane and still have the ability to predict the VMCG and VMCA of the airplane.
ContributorsHadder, Eric Michael (Author) / Takahashi, Timothy (Thesis advisor) / Mignolet, Marc (Committee member) / White, Daniel (Committee member) / Arizona State University (Publisher)
Created2016
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Description
In today’s day and age, the use of automated technology is becoming increasingly prevalent. Throughout the aerospace industry, we see the use of automated systems in manufacturing, testing, and, progressively, in design. This thesis focuses on the idea of automated structural design that can be directly coupled with parametric Computer-Aided

In today’s day and age, the use of automated technology is becoming increasingly prevalent. Throughout the aerospace industry, we see the use of automated systems in manufacturing, testing, and, progressively, in design. This thesis focuses on the idea of automated structural design that can be directly coupled with parametric Computer-Aided Drafting (CAD) and used to support aircraft conceptual design. This idea has been around for many years; however, with the advancement of CAD technology, it is becoming more realistic. Having the ability to input design parameters, analyze the structure, and produce a basic CAD model not only saves time in the design process but provides an excellent platform to communicate ideas. The user has the ability to change parameters and quickly determine the effect on the structure. Coupling this idea with automated parametric CAD provides visual verification and a platform to export into Finite Element Analysis (FEA) for further verification.
ContributorsAnderson, Benjamin Kyle (Author) / Takahashi, Timothy (Thesis advisor) / Bolukbasi, Akif (Committee member) / Patel, Jay (Committee member) / Arizona State University (Publisher)
Created2017
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Description
This paper describes the development of a software tool used to automate the preliminary design of aircraft wing structure. By taking wing planform and aircraft weight as inputs, the tool is able to predict loads that will be experienced by the wing. An iterative process is then used to select

This paper describes the development of a software tool used to automate the preliminary design of aircraft wing structure. By taking wing planform and aircraft weight as inputs, the tool is able to predict loads that will be experienced by the wing. An iterative process is then used to select optimal material thicknesses for each section of the design to minimize total structural weight. The load analysis checks for tensile failure as well as Euler buckling when considering if a given wing structure is valid. After running a variety of test cases with the tool it was found that wing structure of small-scale aircraft is predominantly buckling driven. This is problematic because commonly used weight estimation equations are based on large scale aircraft with strength driven wing designs. Thus, if these equations are applied to smaller aircraft, resulting weight estimates are often much lower than reality. The use of a physics-based approach to preliminary sizing could greatly improve the accuracy of weight predictions and accelerate the design process.
ContributorsKolesov, Nikolay (Author) / Takahashi, Timothy (Thesis director) / Patel, Jay (Committee member) / Kosaraju, Srinivas (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
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Description
Standard procedures to estimate en-route aircraft performance rely upon the “standard atmosphere”. Real-world conditions are then represented as deviations from the standard atmosphere. Both flight manuals and aircraft designers make heavy use of the “deviation method” to account for geographical and temperature differences in atmospheric conditions. This method is often

Standard procedures to estimate en-route aircraft performance rely upon the “standard atmosphere”. Real-world conditions are then represented as deviations from the standard atmosphere. Both flight manuals and aircraft designers make heavy use of the “deviation method” to account for geographical and temperature differences in atmospheric conditions. This method is often done statically, choosing a single deviation based on temperature and a single wind speed for the duration of an entire mission.

Real-world atmospheric conditions have an incredible amount of variation throughout any given flight route, however. Changes in geographic location can present many changes within the atmosphere; they include differences in air temperature, humidity, wind speeds, wind directions, air densities, and more. Historically, these changes have not been accounted for in standard mission performance models. However, they present major possible impacts on real missions.

This thesis addresses this issue by developing a lateral and vertical mission simulation method that uses real-world and up-to-date atmospheric conditions to determine the effect of changing atmospheric conditions on en-route performance and economy. The custom toolset was used in combination with a series of trades over a series of five days and a representation of each season to show the variation that occurs on a single route over the course of daily and seasonal periods.

Both qualitative and quantitative effects from this perspective were recorded for the Airbus A320 and a student designed regional jet, the Aeris, to determine the effect of atmospheric variation on standard commercial transport and hypothetical high-altitude capable commercial transport. The variance presented by changing atmospheric conditions is massive and has large implications on future aircraft operations and design.

Due to large geographical and temporal variation in the wind speeds and directions, it is recommended that aircraft operators use daily measurements of atmospheric conditions to determine optimal flight paths and altitudes. Further investigation is recommended in terms of the effect of changing atmosphere for design, however from initial investigations it appears that a statistical method works well for incorporating the large variance added by real-world conditions.
ContributorsThomaas, Philip (Author) / Takahashi, Timothy (Thesis advisor) / Niemczyk, Mary (Committee member) / Herrmann, Marcus (Committee member) / Arizona State University (Publisher)
Created2019