1.5-stage Air-Axial-Turbine „MIGH“ under Construction

 

The test rigs main component is formed by the 1.5-stage axial turbine. Due to its two-parts design, the turbine may be opened by pushing the anterior part outwards. Consequentely, the effort to change sealing configurations or to vary the axial gap between the blade rows using spacer rings remains low. The outside casing may be rotated in all instrumented areas, thus enabling measurements over a wide circumferential range. To enforce a symetrical flow in circumferential direcation, a honeycomb rectifier is mounted downstream of the inlet housing, at the inlet of the main flow channel. As a result, reproducibility of all measurements should not be influenced by circumferential asymmetries. A clutch connects the shaft at the turbine outlet with an eddy current brake, which serves the purpose of controlling the turbines speed and power. Compressed air is supplied by the institutes 6-stage radial high pressure compressor. A screw compressor supplies the turbine with the necessary sealing air.

 

Applications

  • Investigation of hot gas penetration in rotor-stator cavities
  • Investigation of sealing effectiveness using different sealing geometries and sealing mass flow
  • Investigation of hot gas and sealing gas interaction
 

Measurement Technology

  • Steady and unsteady pressure measurements
  • High precision temperature measurements (thermo couples and resistance thermometers)
  • CO2-Concentration measurements to determine sealing effectiveness
 

Technical design data of the air turbine (current design)

Inlet pressure [bar]

3

Pressure ratio [-]

1.5

Turbine inlet temperature [°C]

75

Mach number [-]

0.55

Axial Reynoldsnumber [-]

1.1x106

Speed [1/min]

9,000

Massflow [kg/s] 5