Stress Evaluation of Low Pressure Steam Turbine Rotor bBlade and Design of Reduced Stress Blade

Abstract

The low pressure steam turbine blade rows have a history of stress failure . They suffer fromtensile and bending stresses partly due to the centrifugal force as a result of high rotationalspeeds and partly due to high pressure, temperature and speed steam loading. The centrifugalforce is one of the problems that face the designers of turbine blades especially the long ones.The designer always aims at reducing these stresses. One way to do so is by the reduction of blademass. That is to make the blade of variable cross section stead in of straight. This paper presentsthe method of reducing cross section. Analysis of such blade is also done as applied to the (P 23-14A) steam blade.