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Experimental and Computational Investigation of a Rotating Bladed Disk under Synchronous and Non-Synchronous Vibration

Kurstak, Eric
http://orcid.org/0000-0002-3829-6498
http://rave.ohiolink.edu/etdc/view?acc_num=osu1617203965442728

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Mechanical Engineering.
Turbomachinery, like jet engines and industrial gas turbines in power plants, are very advanced and complex machines. Due to the complexity and cost of modern turbomachinery, there is active research in accurately predicting the physical system dynamics using computational models. Two big mechanisms that affect the structural response are the prestress effects from high rotational speeds and mistuning effects from tolerance deviations, wear, or damage. Understanding the role these two mechanisms play in the computational modeling of these systems is an important step toward a complete digital twin of an entire jet engine. There previously existed modeling methods that enabled each to be analyzed independently, but not simultaneously in an efficient manner. This will be one of the focus points of this dissertation. The other focus being an experimental investigation into exciting system resonances of a rotating bladed disk using air jets. These experiments will be used to validate the computational modeling method developed. This dissertation has three primary objectives. The first objective is to present reduced order modeling methods that allow for the efficient modeling of coupled systems and rotating systems, both with small or large mistuning. By efficiently including these mechanisms, more realistic boundary conditions can be used to help validate the reduced order models (ROMs) with experimental data. Both modeling methods create models a fraction of the size of the full model while retaining key dynamic characteristics of the full model. The second objective of this work is to show the capability of air jets in exciting synchronous and non-synchronous vibrations in a rotating bladed disk. Much previous research in this field focused on experiments with stationary systems. These tests can help isolate specific mechanisms that may be present in bladed disks, but may limit the applicability of the results to actual rotating systems. This work presents a method of using air jet excitation to cause the desired vibratory response on a rotating bladed disk. The blade vibrations are measured using a non-contacting stress measurement system; the blade tip timing system used in this work uses lasers to measure when a blade arrives at a specific circumferential location and can use the deviations in arrival times to calculate the blade tip deflection amplitudes. This allows the system to rotate and does not change the structural properties of the blades themselves. The third and final objective of this work is to use the presented ROM methods to match the experimental results and investigate the deviations in the results of the models and experiments. The insights into updating computational models such that they predict physical system responses will help inform areas that need more attention in future modeling methods.
Kiran D'Souza (Advisor)
Randall Mathison (Committee Member)
Manoj Srinivasan (Committee Member)
Herman Shen (Committee Member)
156 p.
Mechanical Engineering
turbomachinery; jet engine; gas turbine; vibration; tip timing; traveling wave excitation; finite element; reduced order model; mistuning; experimental mistuning study; computational simulation; bladed disk; damping

Recommended Citations

Citations

  • Kurstak, E. (2021). Experimental and Computational Investigation of a Rotating Bladed Disk under Synchronous and Non-Synchronous Vibration [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1617203965442728

    APA Style (7th edition)

  • Kurstak, Eric. Experimental and Computational Investigation of a Rotating Bladed Disk under Synchronous and Non-Synchronous Vibration. 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1617203965442728.

    MLA Style (8th edition)

  • Kurstak, Eric. "Experimental and Computational Investigation of a Rotating Bladed Disk under Synchronous and Non-Synchronous Vibration." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1617203965442728

    Chicago Manual of Style (17th edition)

osu1617203965442728
191
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This open access ETD is published by The Ohio State University and OhioLINK.