Publication Date


Document Type


Committee Members

George Huang (Committee Member), David Johnston (Committee Member), Joseph Slater (Other), Mitch Wolff (Advisor)

Degree Name

Master of Science in Mechanical Engineering (MSME)


A computational study was conducted to understand the influence of aircraft inlet distortion flow on the unsteady aerodynamic loading of a gas turbine fan stage. A single stage, transonic fan design with no inlet guide vanes was modeled with a commercial, computational fluid dynamics solver, STAR-CCM+, using the harmonic balance technique. The baseline inlet boundary condition applied to the model is consistent with that of a homeomorphic variant of the M2129 S-duct, and exhibited stagnation pressure distortion and a swirl pattern. The baseline inlet flow was decomposed and parameterized into a set of inlet boundary conditions which were individually applied in a series of computational runs. The parametric effect of the swirl velocity on the unsteady aerodynamic loading of the fan blade was studied. The flow structure at 90% span was investigated and revealed localized flow patterns in the blade row. A Fourier analysis revealed that the inlet distortion did not simply convect with the flow, but changed strength along the streamline, redistributing the spectral energy of the pressure and velocity components, and was dependent on the swirl parameter value. The inlet distortion also caused the passage shock to move up to 12% of the blade chord. Finally, the first six harmonics of the inlet distortion contributed significantly to the aerodynamic loading of the transonic fan.

Page Count


Department or Program

Department of Mechanical and Materials Engineering

Year Degree Awarded


Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.