Specialists in Linear Flow Analysis

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 |
---|---|

Pitch | 56.55 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 × 10^{6}.

Flow-Field Plot | C_{p} Plot |
Isentropic Mach Number Plot |
RPMTurbo Solution |
---|---|---|---|

[Data] |

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.

C_{p} Plot (Pressure Surface) |
C_{p} Plot (Suction Surface) |
RPMTurbo Solution |
---|---|---|

[Data] |

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 |
---|---|

[Data] |