15th European Conference on Turbomachinery Fluid dynamics & Thermodynamics

Paper ID:


Main Topic:

Combustor Interaction



Andrea Notaristefano - Politecnico di Milano, Italy
Giacomo Persico - Politecnico di Milano, Italy
Paolo Gaetani - Politecnico di Milano, Italy


Turbulence intensity is a key parameter in turbine aerodynamics. In the open literature, many papers discuss the impact of turbulence intensity on the performance of turbine stages. Furthermore, CFD computations require the turbulence intensity as an inlet boundary condition and a reliable value must be set to get accurate results. In common practice, turbine stages or cascades are tested under turbulence levels generated by grids; in the case of combustor – turbine interaction tests, combustor simulators replace real combustors and modify the turbulence content. Measuring the turbulence intensity generated by combustor simulators directly in the test rigs is often unviable, due to geometrical constraints. Therefore, a viable option is to characterize the turbulence intensity of the combustor simulator off-line. For this purpose, the turbulence intensity of a combustor simulator used in a wide experimental campaign at Politecnico di Milano is measured by means of a hot-wire probe in a blow-down wind tunnel and the results are compared to CFD computations. This combustor simulator can generate at its exit a swirl profile or a combination of a swirl profile with a steady / unsteady temperature disturbance. In the case of the unsteady temperature disturbance, hot-wire measurements are phase-averaged at the frequency of the injected perturbation. The combustor simulator turbulence intensity is measured at two different axial positions to properly qualify the condition found at the stator inlet of the turbine stage studied in the experimental campaigns. Furthermore, the turbulence intensity is also measured by a fast response pressure probe and the results are compared with those of the hot-wire.


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