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.

An experimental investigation was conducted to calculate the aerodynamic drag on a cyclist wearing different types of clothing. The different outfits worn for this experiment were a professional skinsuit, a professional cycling kit, a t-shirt and shorts, and a long-sleeved flannel and jeans. The aerodynamic drag was ultimately found using the coast down method, a process in which a cyclist increases their speed to a chosen maximum threshold, and upon reaching this speed, ceases the pedal stroke and maintains the aero position until the bicycle comes to a stop. The data was gathered using an AeroPod, speed sensor, and GPS unit. The data gathered was imported into Excel for data analysis. The average CdA values at race speed (26-30 ft/s) for the skinsuit, cycling kit, t-shirt and shorts, and flannel were calculated to be 4.180 ft2, 3.668 ft2, 4.884 ft2, and 4.223 ft2, respectively. These race speed averages were found using data from three separate Ironman Triathlons. The cycling kit was found to be the most aerodynamic at the race speed. The results of this study reveal that cycling apparel can only be optimized for a small range of speeds and cycling outside of this optimal range delays the initiation of the reduction of boundary layer separation, thus resulting in more critical time spent in the flow transition region. The skinsuit’s performance was more aerodynamically efficient than the cycling kit at speeds greater than 36.8 mph. The cycling kit is more aerodynamic for speeds slower than 36.8 mph. The slickness of the skinsuit was found to be detrimental to the cyclist’s aerodynamic drag, as the lack of roughness on the skinsuit prevented the initiation of turbulent flow, which results in a decrease in drag. Overall, the experiment confirmed the hypothesis that a cyclist is more aerodynamic when wearing cycling apparel as opposed to casual, loose-fitting clothing.

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.

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.

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.

In a society that is becoming more technologically driven, it is important to have people to design, test, and build new things in order for society to progress. This is oftentimes the role of an engineer. However, engineering school is not easy, and engineering students don’t always make it all the way through school to get an engineering job. This thesis is an in-depth analysis of an engineering student’s path - from choosing engineering as a major to ultimately transitioning into a full-time engineering job. It will do this by covering (1) what engineering is and what career opportunities exist within the discipline, (2) common pitfalls that students may encounter while going through engineering school, (3) how to get an engineering job in industry, and (4) how to appropriately transition into an industry job using the skills from engineering school. While talking about what engineering is and what career opportunities exist, this thesis will discuss engineering as a profession, the ABET accreditation board, and careers in industry vs academia. As part of common pitfalls that engineering students face, this thesis will discuss tenure track, theory vs reality, cooperative learning, and misconceptions about engineering. In order to talk about how to get an industry job, this thesis will discuss the impact of grades, relevant experience, communication, personal branding, and industry options. Finally, while talking about effectively transitioning into industry, this thesis will discuss understanding the skills gained from engineering school, the different roles in industry, and how to appropriately apply those skills. Ultimately this thesis aims to be a resource for students interested in engineering so that they can understand how to successfully make it through school and move into the work force effectively.

Intellectual property law and the controversy surrounding its nuances, loopholes, and obscure definitions have existed and grown since the inception of the original U.S. Constitution. The original idea was to legislate a way so that innovators and inventors of every generation could be incentivised to create new products which could increase the efficiency and productivity in all aspects of American life. However, the generalizations placed in the law, perhaps for the purpose of giving inventors more leeway, has become, over time, a double-edged sword. Because lawsuits and the lucrative settlements that follow were attached to violating intellectual property law, other individuals have mischievously used this to their advantage, namely creating as many random ideas as possible and patenting them so that when someone ingeniously creates an actual product or physical manifestation, those individuals can sue that inventor for supposedly “stealing” their “idea”. These individuals are basically unable to bring their idea to life so they set traps for those who can. So the law, which originally was supposed to motivate Americans to create has now become a weapon that can be used against those true innovators. Our topic then is to look more in-depth at a specific aspect under the broad umbrella of intellectual property law: can intellectual property law apply to biotechnology? We want to look into different forms of biotechnology, medical devices, and pharmaceuticals, observe where patent law has deviated from its original path and where it is going.

The objective of this study is to understand how to integrate conical spike external compression inlets with high bypass turbofan engines for application on future supersonic airliners. Many performance problems arise when inlets are matched with engines as inlets come with a plethora of limitations and losses that greatly affect an engine’s ability to operate. These limitations and losses include drag due to inlet spillage, bleed ducts, and bypass doors, as well as the maximum and minimum values of mass flow ratio at each Mach number that define when an engine can no longer function. A collection of tools was developed that allow one to calculate the raw propulsion data of an engine, match the propulsion data with an inlet, calculate the aerodynamic data of an aircraft, and combine the propulsion and aerodynamic data to calculate the installed performance of the entire propulsion system. Several trade studies were performed that tested how changing specific design parameters of the engine affected propulsion performance. These engine trade studies proved that high bypass turbofan engines could be developed with external compression inlets and retain effective supersonic performance. Several engines of efficient fuel consumption and differing bypass ratios were developed through the engine trade studies and used with the aerodynamic data of the Concorde to test the aircraft performance of a supersonic airliner using these engines. It was found that none of the engines that were tested came close to matching the supersonic performance that the Concorde could achieve with its own turbojet engines. It is possible to speculate from the results several different reasons why these turbofan engines were unable to function effectively with the Concorde. These speculations show that more tests and trade studies need to be performed in order to determine if high bypass turbofan engines can be developed for effective usage with supersonic airliners in any possible way.

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.

Each year, the CanSat Competition organizers release aerospace based engineering mission objectives for collegiate teams to compete in. This year, the design is an aerodynamically stable probe that will descend from an altitude of 725 meters at a rate between 10-30 meters/sec until it reaches an altitude of 300 meters, where it will then release a parachute as its aerobraking mechanism as it descends at 5 meters/sec until it reaches the ground. The focus of this paper is to investigate the design of the probe itself and how slender body theory and cross flow drag affect the lift and aerodynamic stability of this bluff body. A tool is developed inside of MATLAB which calculates the slender body lift as well as the lift from the cross flow drag. It then uses that information to calculate the total moment about the center of gravity for a range of angles of attack and free stream velocities. This tool is then used to optimize the geometry of the probe. These geometries are used to construct a prototype and that prototype is tested by a drop test from a 6-story building. The initial tests confirm the calculations that the probe, bluff body, is stable and self-correcting in its descent. Future work involves more high-altitude and ground-level tests that will further verify and improve on the current design.