Determining Hysteresis Damping in a Steam Turbine Blade using a Finite Element Tool
A. S. N. Saiteja1, C.H. Pavan Kumar2
1A.S.N. Saiteja, Department of Mechanical Engineering, K.L. University, Guntur, Andhra Pradesh, India.
2C.H.Pavan Kumar, Department of Mechanical Engineering, K.L. University, Guntur, Andhra Pradesh, India.
Manuscript received on 09 January 2013 | Revised Manuscript received on 18 January 2013 | Manuscript Published on 30 January 2013 | PP: 32-35 | Volume-2 Issue-2, January 2013 | Retrieval Number: B0359012213 /2013©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Damping is a phenomenon by which mechanical energy is dissipated, usually converted as a thermal energy in dynamic systems. The damping caused by friction between the internal planes that slip or slide as the material deforms is called hysteresis damping or material damping. This paper deals with determining hysteresis damping of a typical turbine blade. The damping is quantified as a function of strain amplitude. ANSYS and Hyper Mesh are adopted for necessary calculations. First the natural frequencies and orthonormal mode shapes are obtained at the desired speed. Lazan’s damping law is used to determine the specific damping energy in each element of the blade. Total damping energy and strain energy are calculated by integrating them over the entire volume. With the help of these the loss factor is obtained. From the loss factor, the equivalent viscous damping ratio is determined. Procedure for one mode shape is shown.
Keywords: Damping, Hysteresis, Lazan’s Law, Mode Shapes.
Scope of the Article: Data Mining