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Assessment of Reduced Fidelity Modeling of a Maneuvering Hypersonic Vehicle

Dreyer, Emily Rose
http://rave.ohiolink.edu/etdc/view?acc_num=osu1610018486409227

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Aerospace Engineering.
Balancing accurate and efficient estimation of aerothermodynamic loads is a significant challenge for multi-disciplinary modeling and analysis of high speed vehicles. High fidelity methods are desired in order to minimize modeling uncertainty. However, the need for either online aerothermodynamic modeling or many model iterations often introduces a hard constraint on model run-time that favors the use of classical engineering methods. Thus, systematic characterization of trade-offs in accuracy and run-time costs for different levels of modeling fidelity is a critical need. Technical challenges toward this need include the wide range of operating conditions and parameters associated with a complete vehicle, as well as the inability to comprehensively assess hypersonic configurations in ground-based facilities. The goal of this dissertation is to systematically study a range of reduced fidelity aerothermodynamics models in order to determine relevant fidelity. This is carried out by first examining the impact of analytical and data-driven model reductions over a broad parameter space in the context of steady-state aerothermodynamic loads. This work builds on previous by extending existing approaches to accommodate a complete three-dimensional hypersonic geometry. Three models for pressure are investigated: two of the models are kriging interpolants of either Reynolds-averaged Navier-Stokes (RANS) or Euler computational fluid dynamics (CFD) data, and the third is a shock-expansion model. Four models for heat flux are investigated: a kriging interpolant of RANS CFD; an Eckert's reference temperature model using a kriging interpolant of RANS CFD pressure; an Eckert's reference temperature model using kriging interpolants of Euler CFD pressure and temperature; and an Eckert's reference temperature model using shock-expansion theory pressure and temperature. The reduced models are compared to RANS CFD predictions on the surface of a complete hypersonic vehicle over a broad operational space. The results and conclusions highlighted trade-offs in the context of accuracy and computational requirements for different types of loads models for use in multi-disciplinary simulations of high-speed vehicles. The second part of this work explores the degree of unsteadiness in integrated aerodynamic loads at representative reduced frequencies for a pitching vehicle. A typical approach is to assume unsteady aerodynamic loads as either steady-state or quasi-steady. The former assumes that the aerodynamic loads only depend on the instantaneous inclination angle, while the latter includes a pressure perturbation due to an induced inclination angle from surface velocity. Unsteadiness in integrated aerodynamic loads is assessed at the component level and on a complete vehicle with and without viscous effects. Results indicate that both unsteadiness and the importance of viscosity in integrated aerodynamic loads increase with three-dimensionality of the flow. Three-dimensionality enhances load hysteresis due to flow unsteadiness, while fin-body flow interactions are found to increase the lift-curve slope of the dynamically pitching vehicle. Compared to a control surface in isolation, viscosity has a strong, albeit complex, influence on deviations of fully unsteady loads models from quasi-steady and steady models. The precise mechanisms that drive a relatively rapid divergence from quasi-steady flow for the complete vehicle remain inadequately understood and additional study is needed.
Jack McNamara, Professor (Advisor)
Carlos E.S. Cesnik, Professor (Committee Member)
Jen-Ping Chen, Professor (Committee Member)
Reasor Reasor, Ph.D. (Committee Member)
Mei Zhuang, Professor (Committee Member)
Abdollah Shafieezadeh, Professor (Committee Member)
117 p.
Aerospace Engineering; Engineering; Mechanical Engineering; Statistics
hypersonic; computational fluid dynamics; reduced order modeling; piston theory; kriging; aerothermodynamics; Eckerts reference; aerodynamics; rigid body motion; high speed; quasi steady

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Citations

  • Dreyer, E. R. (2021). Assessment of Reduced Fidelity Modeling of a Maneuvering Hypersonic Vehicle [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1610018486409227

    APA Style (7th edition)

  • Dreyer, Emily. Assessment of Reduced Fidelity Modeling of a Maneuvering Hypersonic Vehicle. 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1610018486409227.

    MLA Style (8th edition)

  • Dreyer, Emily. "Assessment of Reduced Fidelity Modeling of a Maneuvering Hypersonic Vehicle." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1610018486409227

    Chicago Manual of Style (17th edition)

osu1610018486409227
486
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