Profile Loss of a Printed Transonic Turbine Cascade

Abstract

Profile losses of turbine blades are one of the main problems in turbine technology. Besides the occurring aerodynamic effects, it is well known that the surface roughness has a significant influence on these losses. It is generally known that a better surface quality leads to lower profile losses. Many studies for this topic are given in open-source literature, but the investigations were mainly performed in an ideal gas atmosphere (air). The present contribution presents the results of an experimental study of profile losses of an additive manufactured linear turbine cascade placed in the test section of a closed-loop organic vapor wind tunnel, or CLOWT for short. The investigations are carried out under an organic superheated steam atmosphere. For this organic vapor atmosphere, the of carbon based liquid Novec™ 649 has been used. In addition, measurements were also realized in an air atmosphere. To get different point of views, three different approaches are chosen to determine the profile losses.