**Prediction Of Stress Concentration Effect Under Thermal And Dynamic Loads On A High Pressure Turbine Rotor**

**R. Nagendra Babu**^{1}**, K. V. Ramana**^{2}** and K. Mallikarjuna Rao**^{3}

^{1}Department of Mechanical Engineering, Sree Vahini Institute of Science & Technology, Tiruvuru - 521235

^{2}Department of Mechanical Engineering, KL College of Engineering, Vaddeswaram, A.P. (INDIA)

^{3}Department of Mechanical Engineering, JNTU College of Engineering, Kakinada – 533002 A.P. (INDIA)

ABSTRACT

Geometric discontinuities cause a large variation of stress and produce a significant increase in stress. The high stress due to the variation of geometry is called as ‘stress concentration’. This will increase when the loads are further applied. There are many investigators who have studied the stress distribution around the notches, grooves, and other irregularities of various machine components. This paper analyses the effects of thermal and fatigue load on a steam turbine rotor under the operating conditions. Stresses due to thermal and dynamic loads of High Pressure Steam Turbine Rotor of 210MW power station are found in two stages. A source code is developed for calculating the nominal stress at each section of HPT rotor. Maximum stress is obtained using FEA at the corresponding section. Thermal and Fatigue Stress Concentration Factors at each section are calculated. It is observed that the SCF due to the combined effect of thermal and dynamic loads at the temperatures beyond 5400C is exceeding the safe limits.

**Keywords**: Stress Concentration Factors, HPT Rotor, Thermal and dynamic loads.

**International
eJournal of Mathematics and Engineering**

Volume 1, Issue 4, Pages: 667 – 678