On the Cause of Deflection of the Turbine Shaft during Heat-Indication Test

On the Type A, C' and D deflections

Abstract

In order to investigate into the cause of various deflections liable to take place in turbine shafts during heat-indication test, the authors reproduced deflections experimentally using model shafts as big as about 1/3-1/6 in dimensions of an actual shaft.
Thus, it was made clear that, besides the physical properties of a shaft itself, surface conditions of a shaft such as the way of sticking of dirts and scales, and conditions of machined surface possibly would be important causes for appearance of the deflections.
A new type of deflection which, though seemingly resembling the type C deflection, would be due to causes quite different from the said type C was found and designated as type C' deflection. Further it has been made clear that, as well as the deflection of types A and D, this C' type probably would be ascribed to an asymmetric thermal emissivity on the surface of a shaft.
The results thus obtained from the tests of model shafts were confirmed in practical heatindication tests of turbine shafts