The series of tests were conducted on the two-stage low-pressure model turbine with the eddy-current brake. The layout of the turbine test rig is presented in Fig. 1. A two-fan set with a specially equipped control system provided a continuous and strictly constant airflow to the test rig. The inlet air parameters during the tests presented here were as follows: total pressure pt0 = 15.668 ± 0.003 kPa, total inlet temperature Tt0 = 318 ± 2 K, mass fbw rate m = 3.565 ± 0.005 kg/s (n = 49.2 Hz) to m = 3.730 ± 0.005 kg/s (n = 30 Hz) – variations were due to the clocking effect. During the tests the rotational speed n was in the range 25.00 to 58.33 Hz (1500 rpm to 3500 rpm). Variation of the speed n at the working point was less then 0.02 Hz (1 rpm) during every measurement session. Fig. 2 shows the cross section of the test rig with the main measuring planes and Fig. 3 shows the performance curves of the machine.
The turbine geometry with some indexing positions of the first stator vane (pos. 5 ^ x/T = 0.0 ^ identical circumferential position of both stators) is presented in Fig. 4. For tests presented herein both identical stators have 16 constant-section cylindrical vanes with the trailing edge inclined to the radial direction at an angle of 22 deg. Both identical rotors have 96 twisted blades. This atypical machine with a very clear stator wake presence is an interesting case from the numerical point of view. A more detailed description of the test facility geometry and the unsteady flow measurement can be found in our earlier studies [Krysinski et al. 1995 – 2002, Smolny, Blaszczak 1997].