Turbine Engine Rotordynamic Evaluation. Volume I.
Final rept. 1 May 75-1 Jun 76,
MECHANICAL TECHNOLOGY INC LATHAM N Y
Pagination or Media Count:
Eight jet engine models within the Air Force inventory the T56, J57, J79, J85, TF30, TF33, TF39 and TF41 have been analyzed to determine critical speeds, unbalance response, blade loss effects and maneuver deflections. The effects of dampers, thrust loads and balancing requirements, while not analyzed in depth, were noted where applicable in the description of the engines dynamic behavior. Each rotor design was then classified into categories of dynamic sensitivity. Five test elements were manufactured and vibrated to obtain experimental data for correlation with analytical modeling predictions. The four cylindrical elements, each of which incorporated either a steep cone, shallow cone, flat plate or thin shell, were excited to obtain the first three lateral natural frequencies. Because of manufacturing problems with hardness and weld penetration, measured frequencies were below those predicted. The fifth test element was a machined flexible bearing support for use in parallel with a squeeze film damper. After static and dynamic testing of this representative flexible bearing support, the results were within 10 of the analytical prediction for this element. The information from this analytical and experimental study has resulted in a technology plan whose goal is to improve the technological capabilities for the purpose of reducing costs associated with reliability and maintainability of U.S. Air Force engines. Author
- Jet and Gas Turbine Engines