Conjugate heat transfer investigation of impingement cooling for ribbed internal passage of a turbine vane

Abstract

In this study, the effect of internal cooling configuration on overall cooling effectiveness of gas turbine vane is investigated using conjugate heat transfer approach. The C3X turbine vane with internal cooling and a turbine vane leading edge model with combined impingement and film cooling scheme are used as primary cases. An impingement cooling configuration is designed in order to enhance cooling effectiveness on the leading edge of the internally cooled C3X vane. In an attempt to further improvement, two rows of ribs are added on regions where impingement jets do not cover. In the leading edge model, the effect of modification for internal cooling channel and within film cooling holes are investigated by adding different rib configurations in those regions. The SST model is adopted for turbulence modeling in fluid zones. In the C3X vane, overall cooling effectiveness is generally enhanced using impingement cooling configuration. Furthermore, span wise distribution of overall cooling effectiveness becomes uniform in the leading edge of the vane. In the leading edge model, it is found that overall cooling effectiveness is varied due to the change in distribution of coolant flow in internal cooling channel and on external surface of the vane by adding ribs in internal cooling channel. The case with ribs perpendicular to the internal channel cross flow provides higher overall effectiveness. The results also indicate that cooling performance of the film cooled vane is sensitive to the location of ribs installed within film holes. The interaction between coolant flow and hot gas flow and its contribution in cooling performance of the vane are elaborately discussed for the leading edge model.