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- All Subjects: Aircrafts
- Creators: Wells, Valana
- Member of: Theses and Dissertations
Description
The purpose of my Honors Thesis was to generate a tool that could be implemented by Aerospace students at Arizona State University. This tool was created using MatLab which is the current program students are using. The modeling system that was generated goes step-by-step through the flow of a two spool gas turbine engine. The code was then compared to an ideal case engine with predictable values. It was found to have less than a 3 percent error for these parameters, which included optimal net work produced, optimal overall pressure ratio, and maximum pressure ratio. The modeling system was then run through a parametric analysis. In the first case, the bypass ratio was set to 0 and the freestream Mach number was set to 0. The second case was with a bypass ratio of 0 and fresstream Mach number of 0.85. The third case was with a bypass ratio of 5 and freestream Mach number of 0. The fourth case was with a bypass ratio of 5 and fresstream Mach number of 0.85. Each of these cases was run at various overall pressure ratios and maximum Temperatures of 1500 K, 1600 K and 1700 K. The results modeled the behavior that was expected. As the freestream Mach number was increased, the thrust decreased and the thrust specific fuel consumption increased, corresponding to an increase in total pressure at the combustor inlet. It was also found that the thrust was increased and the thrust specific fuel consumption decreased as the bypass ratio was increased. These results also make sense as there is less airflow passing through the engine core. Finally the engine was compared to two real engines. Both of which are General Electric G6 series engines. For the 80C2A3 engine, the percent difference between thrust and thrust specific fuel consumption was less than five percent. For the 50B, the thrust was below a two percent difference, but the thrust specific fuel consumption clearly provided inaccurate results. This could be caused by the lack of inputs provided by General Electric. The amount of fuel injected is largely dependent on the maximum temperature which is not available to the public. Overall, the code produces comparable results to real engines and can display how isolating and modifying a certain parameter effects engine performance.
ContributorsCook, Rachel Nicole (Author) / Dahm, Werner (Thesis director) / Lee, Taewoo (Committee member) / Wells, Valana (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
Winglets and wingtip structures have been prominent in commercial aircraft design in the past few decades. These designs are known to reduce the induced drag on an aircraft wing, thus increasing its overall fuel efficiency. Several different winglet designs exist, and little reason is offered as to why different winglet designs are used in practice on different aircraft, especially those of variable range. This research tests existing winglets (no winglet, raked winglet, flat plate winglet, blended winglet, and wingtip fence) on a span-constrained wing planform design both computationally and in the wind tunnel. While computational tests using a vortex lattice code indicate that the wingtip fence minimizes induced drag and maximizes lift to drag ratio in most cases, wind tunnel tests show that at different lift coefficients and angles of attack, the raked winglet and blended winglet optimize the aerodynamic efficiency at incompressible flow velocities. Applying the wing aerodynamic data to existing variable range commercial aircraft, mission performance analysis is run on a Bombardier CRJ200, Airbus A320, and Airbus A340-300. By comparing flight lift coefficients in cruise for these aircraft to the lift coefficients at which winglets minimize drag in compressible flows, optimal winglet designs are chosen. It is found that the short range CRJ200 is best equipped with a flat plate or blended winglet, the medium range A320 can reduce drag with either a wingtip fence, raked winglet, or blended winglet, and the long range A340 performs best with a flat plate, blended, or raked winglet. Overall, despite the discrepancy in winglet selection depending on which experimental results are used, it is clear that addition of a winglet to a span-constrained wing is beneficial in that it reduces induced drag and therefore increases overall fuel efficiency.
ContributorsOremland, Joshua Elan (Author) / Wells, Valana (Thesis director) / Mertz, Benjamin (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05