RotKa

  Copyright: © IKDG  

The main component of the test rig is the rotating turbine disk in a closed housing.

The rotating turbine disk is supplied with cooling air, which is injected through a total of eight nozzles at circumferentially symmetrical positions on a constant radius. This configuration is in general based on a first low-pressure turbine stage of a real aero engine. The air supply to the test rig is ensured by a compressor from the institute.

In order to be able to investigate the heat transfer between the cooling air introduced and the rotating turbine disk, temperature steps of up to 100 K are realized in the cooling air supply via an electric heater. This generates a significant heat flow in the direction of the rotating turbine disk. The heat transfer coefficients between the cooling air and the turbine disk can be determined from the measured disk surface temperatures in conjunction with numerical models. In addition, optical access points on the test rig allow investigation of the flow structures occurring in the rotor-stator cavity.

 

Applications

• Investigation of heat transfer between cooling air and turbine disk
• Thermoshock investigations
• Investigation of the flow phenomena occurring in the rotor-stator cavity

 

Measurement Technology

• 30 type-T thermocouples on the disc surface of the rotor
  • 18 x disc front surface (9 radii, 2 angles)
  • 6 x bore/disc inner surface (3 axial positions, 2 angles)
  • 6 x disc back surface (3 radii, 2 angles)
  • Holes in the rotor for carrying out the cables
• 20 thermocouples for air temperatures in the test chamber annulus
• Measurement of air temperatures and static pressures of the inflow just before entering the nozzles
• Static pressures in both cavities
• Zonal stereo PIV measurements
  • Different laser light section planes adjustable
  • Two cameras aligned at 90° to each other capture all three velocity components

 

Technical design data

Inlet pressure [bar]	1,5
Inlet temperature [°C]	40-140
Mach number at nozzle inlet [-]	0.56
Reynolds number at nozzle inlet [-]	22.7 * 103
Speed [1/min]	11,700
Mass flow [kg/s]	1.2
Rotor outer diameter [mm]	540
Rotor total weight [kg]	approx. 100
Rotor driving power [kW]	35

 

Duration and Project Partners

The project is financially supported by the BMWK and MTU.

MTU provides the chairman of the associated project committee.