자료유형  

 학위논문

Control Number  

0016931368

International Standard Book Number  

9798379754716

Dewey Decimal Classification Number  

629.1

Main Entry-Personal Name  

Costenoble, Miranda.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Maryland, College Park., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(191 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 84-12, Section: B.

General Note  

Advisor: Baeder, James.

Dissertation Note  

Thesis (Ph.D.)--University of Maryland, College Park, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약In this dissertation, a methodology is presented for lower-fidelity modeling of stacked rotors, with improved accuracy compared to existing lower-fidelity rotor models. This methodology is built on a conventional prescribed vortex wake model of the rotor, with lifting-line airfoil blades. Such a lifting-line model cannot fully capture the aerodynamic interaction between the rotor blades, which are driven heavily by thickness and shape effects. To account for these effects, a high-fidelity 2D CFD code is used to model the airfoil-to-airfoil interaction along the span of the rotor. These 2D CFD loads are then injected into the lifting-line/prescribed wake rotor model, using an iterative technique to account for the changing deflections of the rotor blades.To accurately determine the airfoil-interactional loads along the span of the rotor, it is necessary to have some way to relate the conditions along the span of the rotor in 3D to the airfoil conditions in 2D, and vice-versa. Methods for parameterization of the airfoil system are presented, which account for both the geometry of the rotor/airfoil system and their aerodynamic conditions. Two different methods of relating the airfoil loads back to the rotor are presented, which offer different strategies depending upon the constraints of the underlying rotor model.Any rotor design must include selection of the airfoils on the blades, and stacked rotors are no different. To that end, 2D airfoil simulations are presented, which demonstrate both the necessity of the current methodology, and offer suggestions for future stacked rotor design. 2D airfoil loads are pre-computed (prior to the lower-fidelity rotor simulations) using an established 2D CFD code. Automation of this code allows for rapid generation of large data sets with minimal user input.The combined 2D CFD/3D prescribed wake methodology is presented and validated against recent experimental results. The baseline prescribed wake model is shown to significantly less variation of thrust and power with phase angle than the experiment. Inclusion of lifting-vortex airloads leads to improvements in thrust prediction, but with incorrect magnitude at small phase angles and incorrect power predictions. Only by including the 2D CFD airfoil-interactional airloads are the most accurate results achieved. Multiple inflow and coupling methods are also examined, with discussion of the strengths and limitations of each. Overall, it is believed that the current work should offer the potential for significantly faster and more accurate design of stacked rotors than was previously possible.

Subject Added Entry-Topical Term  

Aerospace engineering.

Subject Added Entry-Topical Term  

Plasma physics.

Subject Added Entry-Topical Term  

Mechanical engineering.

Index Term-Uncontrolled  

CFD code

Index Term-Uncontrolled  

Co-rotating coaxial

Index Term-Uncontrolled  

Rotorcraft

Index Term-Uncontrolled  

Stacked rotors

Added Entry-Corporate Name  

University of Maryland, College Park Aerospace Engineering

Host Item Entry  

Dissertations Abstracts International. 84-12B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:643359