What is it about?

The crankshaft of aircraft’s piston engine is exposed to harmful torsional vibration. If the oscillation reaches high value of amplitude fatigue damage of the propeller system occurs. To avoid this, torsional vibration damper can be mounted onto the free-end of the crankshaft. Visco-dampers are the simplest in structure but one of the most effective type of torsional vibration dampers, which have working fluid of silicone oil. Silicone oil is a non-Newtonian fluid and the highest effect on its lifetime is the temperature. Due to the thermal complexity of the structure and due to the lack of proper thermal measurement technology, it is a challenging task to perform thermal management of the damper especially based on purely analytical way. Numerical methods must be applied in design and development phase of the product to approximate the temperature field for lifetime calculation. A finite-difference-method based 2D thermal calculation procedure has been developed in MATLAB environment in order to reveal the hidden heat transfer processes among the damper components and to approximate the temperature distribution inside the structure with especial care for the silicone oil. The accuracy of the developed thermal model has been verified by a finite-volume-method based engineering software in ANSYS environment. The newly developed and verified thermal model has been used to update the Iwamoto-equation for providing more accurate outer surface temperature for the recently investigated damper housing in analytical way.

Featured Image

Why is it important?

Visco-dampers are spread all over the world considering general purpose applications not only in aircraft engines but also in heavy duty piston engines of military, architectural, agricultural and mining areas. Due to their simplicity and low maintenance, they are often used also in sports cars, trucks and ships. The one of the most reasonable and effective solutions in design and development phases of the visco-dampers is to establish, use and necessarily improve calculation methods. Significant amount of time, capacity and cost can be saved by applying different numerical and analytical methods.

Perspectives

Visco-damper is one of the simplest vibration damping structure, however, performing thermal analyses on it to estimate the lifetime of its working fluid under operating conditions is a challenging task. The authors of this publication provide a short insight into the application possibility of visco-dampers in aviation. A thermal problem has been solved in numerical way and the reader will also learn an empirical formula for preliminary thermal calculations related to visco-dampers.

Márk Venczel
Budapesti Muszaki es Gazdasagtudomanyi Egyetem

Read the Original

This page is a summary of: Model development with verification for thermal analysis of torsional vibration dampers, January 2020, American Institute of Physics,
DOI: 10.1063/5.0026437.
You can read the full text:

Read

Resources

Contributors

The following have contributed to this page