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Institute of Turbomachinery and Fluid Dynamics
Logo Leibniz Universität Hannover
Institute of Turbomachinery and Fluid Dynamics
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Working Group Axial Turbines

Description

The Axial Turbines Group focuses on aerodynamic problems regarding multi-stage axial turbines such as jet engines and turbines for power generation in combined cycle power plants as well as the aero-elasticity of wind turbines. As part of the Collaborative Research Center (SFB) 871, the group addresses innovative methods of health monitoring of aircraft engines. A wide variety of test facilities (e.g. axial air turbine, diffuser rig and rotor blade deformation test rig) and software packages are available for research. 

The volatile power supply generated from renewable energy sources such as wind and solar power demands improved flexibility (i.e. short start-up and shut-down intervals) and increasing part-load operation time spans from conventional and combined-cycle power stations. Simultaneously, it is essential to optimise output efficiencies for a wide spectrum of operating points. The Turbine Group conducts numerical simulations and experimental investigations of multi-stage turbines aiming to gain a more detailed comprehension of steady and unsteady state flow phenomena in turbines and diffusers and to use new insights for the improvement of their respective efficiencies. In particular the interdependencies of influencing factors of both components are investigated. In addition to the analysis of local effects in the flow path, the effectiveness of measures aimed at the reduction of local loss generation in multi-stage turbomachinery is studied using high-pressure steam turbine blades as a test case. 

As the demand for increased power generation in wind turbines continues, blades must be designed to be thinner and longer, while maintaining structural strength and thus aero-elastic effects are increasingly relevant. To ensure and improve the safety and reliability of wind turbines in the future, the group is focusing on aero-elastic modelling and simulation. Simplified models for the simulation of entire wind turbines are developed and probabilistic methods are applied to study the influence of uncertainties in the design. An optical system for the measurement of rotor blade deformations on rotating turbine blades in the field is developed to validate the aero-elastic simulations. Furthermore, two- and three-dimensional numerical simulations are performed for aerodynamic analyses. 

Selection of Completed Projects

  •  Advancement of the Background Oriented Schlieren-Method for the Application in Turbomachinery (Herbst)
  • Aerodynamic and Aeroelastic Rotor-Tower Interaction in Horizontal Axis Wind Turbines (Gomez)
  • The Influence of the Downstream Flow on Windage and the Effect of Windage on Blade Sealing (Binner)
  • Secondary Flow in Turbine Diffusers (Kuschel)
  • Innovative 3D Blade Geometries (Kwitschinski)
  • Unsteady Work Optimized Turbine (Biester/Henke)
  • Influence of the Spinner Geometry on Non-Steady Flow in the Root Area of Blades of Modern Wind Turbines (Lin)
  • Smart Blades: Flow Simulation of Blades with Highly Elastic Trailing Edges (Wolff)

Current Projects

  •  Optical Field Measurements of Rotor Blade Deformation (Lehnhoff)
  • Probabilistic Safety Assessment of Offshore Wind Turbines (Ernst)
  • SFB 871 TP A3 – Assessment of the State of Repair of Jet Engines by Analysis of the Exhaust Jet (Hartmann)
  • Optimised Turbine Blade Shroud Geometry (Kluge/Wein)
  • Innovative Steam Turbine Blade Path for High Performance Density (Bittner)
  • SmartBlades2: Construction, Test and further Development of Intelligent Rotor Blades (Jätz/Wolff)
  • DF Wind: German Research Facility for Wind Energy (Lehnhoff)

Contacts

Group Leader

Dipl.-Ing. Tim Kluge

Assistant Group Leader

Dipl.-Ing. Ulrich Hartmann