Design of a new test rig facility to study the turbine thermal behavior

In the new turbo-gas engines development strategies, the Low Pressure Turbine (LPT) the clearance control and the cooling air reduction for disks and casing will play a central role in reaching the required engine performances. The erosion of the actual margins on these phenomena could be pursued only through the improvement of the numerical simulations accuracy at engine module level. Small air leakages between components or sealing systems can modify significantly the thermal behavior of the turbine module as well as the understanding of the heat transfer modes within the typical LPT large cavities. On the other hand it is virtually impossible obtain experimental data with the accuracy needed to tune numerical approaches if the tests are directly performed on the engine. To overcome these problems an innovative test rig facility has been designed and set up at the Energy Department of the Politecnico di Torino. The rig, able to work at high temperature, simulates the static parts of a LPT (from the main flow to the casing and external Active Clearance Control system) and has been sized considering thermal similitude of main involved phenomena. The present paper deals with: the methodology used to design and size the rig and the Test Article, the description of the main facility features and the analysis of some experimental results.