Session: Student Poster Competition

Submission Number: 187078

Reduction Methodology for Bladed Disk With Transient Cyclically Asymmetric Forcing Cases 

During regular operation, turbomachines operate in extremely harsh environments that can include, but are not limited to, high temperatures, immense centrifugal forces, and occasionally high impact external forces. High impact external forces can have a multitude of causes such as foreign object ingestion or blade tip rubs, to name a few. The components in the turbomachines that will most likely absorb the majority of the impact force are the bladed disks. Bladed disks are one of the most important components in a turbomachine, therefore, it is imperative to understand how any, expected or unexpected, external forces affect the bladed disks. Bladed disks are designed as nominally cyclically symmetric components allowing for efficient single sector analyses to be completed to determine the dynamic response of the bladed disk due to applied forcing. An exception to this is if the applied forces are not also cyclically symmetric the advantages of single sector analyses are greatly reduced. While there are many cyclically symmetric forces acting on the bladed disk, such as aerodynamic forces due to vane passing frequencies, there are also forces such as the aforementioned, high impact external forces that can occur and are not cyclically symmetric. In this poster a novel reduction methodology is presented that allows for the efficient solution for the dynamics of a bladed disk with an external, cyclically asymmetric force applied. The methodology utilizes a single sector model to reduce the entire system, significantly reducing the computational expense while leaving active nodes in the physical coordinate system allowing for easy application of external forces. After presenting the method, the method is compared with full three-dimensional finite element solutions for both a blade tip rub forcing case and a foreign object ingestion forcing case. The presented method shows good agreement with the finite element solution while providing orders of magnitude faster computation times.

Presenting Author: Noah Broski The Ohio State University

Presenting Author Biography: Noah is a PhD Candidate in the Gas Turbine Laboratory at The Ohio State University. Noah's research focuses on the computational modeling of blade tip rub interactions with a specific focus on structural dynamics.

Authors:

Noah Broski The Ohio State University
Randall Mathison The Ohio State University
Kiran D'souza The Ohio State University