Standard Configuration 11 is a 2D turbine profile. The off-design case for this configuration provides a good test to verify the ability of a code to solve the unsteady Navier-Stokes equations.
The co-ordinates of points on the profile surface can be downloaded from the KTH site. Other details about the geometry are shown in the table below.
|Chord Length||77.8 mm|
|Stagger Angle||-40.85 degrees|
There are two steady-state flow conditions defined for Standard Configuration 11: a subsonic case and a transonic off-design case, where flow separation occurs on the suction surface. The flow separates at the leading edge due to the high incident flow angle and re-attaches at approximately 30 percent chord. Only results for the off-design test case are shown here. The details of this flow condition are shown in the table below.
|Total Pressure||229.8 kPa|
|Inflow Angle||34 deg.|
|Exit Isentropic Mach Number||0.99|
We have assumed that the total temperature is 340.0 K for the off-design test case. This is based on the fact that the experimental frequency was 211.6 Hz which corresponded to a reduced frequency of 0.309 (based on full chord). To achieve this value the reference velocity at the exit must have been approximately 334.7 m/s. The Mach number of the flow is assumed to be 0.99 which gives a total temperature of 340.0 Kelvin. The inlet Reynolds for this total temperature is 1.18 × 106.
|Flow-Field Plot|| Cp Plot
|| Isentropic Mach
The unsteady flow response to rigid-body bending normal to chord is shown in the figures below. The reduced frequency is 0.309 (full chord) and the interblade phase angle is 180 degrees.
| Cp Plot (Pressure Surface)
|| Cp Plot (Suction Surface)
The plot of aerodynamic damping versus interblade phase-angle for the off-design test case due to normal bending at a reduced frequency (full chord) of 0.309 is shown below.
|Damping Plot||RPMTurbo Data|