The low-pressure turbine MTU-B illustrates the capability of TRACE to simulate such flows. This turbine has been designed by MTU Aero Engines and tested at the University of Stuttgart. A view of the turbine is presented in Fig.1.
The performance of a low-pressure turbine is dramatically impacted by transition. Hence, it is important to be able to simulate it in design and off-design regimes. The Multimode and the γ-Reθ transition models, implemented in TRACE, are used to compute the flows inside MTU-B at different Reynolds numbers. The computed losses are compared to the measurements in Fig 2.
For both models, the computations show results consistent with the experiments. The efficiency of the turbine decreases when the Reynolds number decreases.
The pressure coefficient distribution along the blades can provide a good indication on how well transition is simulated. Such distributions at different blade heights are shown for vanes 3 and 6. Only the lowest Reynolds number has been considered here.
Fig 3 presents the pressure coefficient distributions on vane 3. For all blade heights, the separation bubble observed during the experiments is quite well simulated by both models. Concerning vane 6, the pressure coefficient distributions are shown in Fig 4.
On this blade also, the separation-bubble present on the suction side is well reproduced by all models. In particular the occurrence of the separation at the different blade heights is successfully simulated.Hence, it has been shown that the transition models in TRACE can provide satisfactory results when simulating multistage low-pressure turbines