• Axial compressor: Design and optimization of a three-stage compressor

  • Completely parameter based geometry generation

  • Shock system at the first stage rotor in working point conditions

  • Assessment of aeroelasticity: flutter stability analysis of rotor geometry

  • Speedlines in the performance map

Design from scratch and optimization of a three-stage compressor (total pressure ratio 6.2) with two axial and one diagonal stage for small scale turboshaft engines in the 80kW class. Basic thermodynamic considerations and parameter studies are carried out to evaluate different compressor concepts. For the application, a three stage compressor consisting of two axial and one diagonal stage is chosen. This concepts represents a reasonable compromise for the lowest SFC at design and off-design conditions but also requires a sophisticated design process due to the multistage configuration. The design and optimization process is conducted with a combined aerodynamic and mechanical optimization for the compressor stages at multiple operating points. Finally, the chosen blade geometry is assessed concerning the aeroelasticity in a flutter-analysis.

  • Analysis induced draft fan: Rotor reconstructed from optical measurements and abs. velocity (unsteady CFD)

  • Flow in the vane control (45° position) and inlet chamber

  • High grid quality structured meshing, full setup contains ~17 million cells

  • Comparison of calculated performance shows good agreement with manufacturers design performance map

  • Flow seen from the rotor (left hand side) and from a stationary frame of reference (right hand side)

Simulation and analysis of a large induced draft fan for power plant applications. Using data of an optical measurement the 3D geometry of rotor and casing is reconstructed. High quality steady and unsteady CFD simulations show good agreement with the manufacturers design performance map. The simulation provides an insight view of the flowfield and detects a flow separation at the rotor as a major source of losses.


  • Optimization radial fan: CFD validation of base design

  • Parametrization of blade geometry for application in an automated optimization process

  • Increase in efficiency by a multiobjective optimization at several operating points

Starting from a CFD validation of the base design the efficiency of a radial fan is set to be improved. Initially the blade geometry is described in aero_designworks geometry generation environment. The parameter based geometry description is crucial for the application of automated optimization. In the multiobjective optimization along with the efficiency in two operating ponts the pressure rise is considered.

  • Axial turbine: Design and optimization of a two-stage axial turbine for turboshaft applications

  • Combined optimization of the two stages with an overall number of 150 free design parameters

  • Performance map of the high pressure stage

  • Inclusion of structural mechanics and dynamics during the optimization

A two-stage axial turbine for a 80kW turboshaft engine is designed from scratch and optimized. Both, the high and low pressure stages are optimized in one combined setup to include stage interaction. The 3D blade generation process for the two stages requires an overall number of 150 free design parameters to be handled during the optimization. The numerical evaluation of members in the optimization uses a process considering aerodynamics as well as static and dynamic (Campbell diagram) machanics. Overall the project illustrates a highly complex optimization that is successful both in final results and with respect to industry competitive timeframe and given computing capacity. Well adapted design and analysis processes play a key role in this challanging task.

  • Small scale wind turbine: Rotor blade design for maximum performance specifically at low wind speeds

  • Meshing of rotating blade domain and stationary farfield

  • Parameter based geometry generation for automated optimization process chain

  • Circumferential averaged axial velocity flowfield at design point conditions

Aerodynamic design of rotor blades for a 1kW small scale wind turbine specifically designed for low wind speeds typically for urban locations. The blades are designed by an automated 3D multiobjective optimization in several operation points with regard to max. efficiency over a broad range of wind speeds and an aerodynamically robust design. The simulation approach is unusual for wind turbines, because a compressible CFD code is applied. This rarely used setup is numerically more difficult to handle, but allows a superior prediction of profile performance due to not neglecting local density changes that occur on the blade surface.

  • V-shape static mixer: Total pressure contours of two mixing components

  • Complex mixer geometry: The CFD mesh is constructed with about 23 million elements and resolves the flow down to the boundary layers.

Assessment of a V-shape mixer at high mass flow rates concerning blending and total pressure loss. The meshing of the complex sheet package and the resolution down to the boundary layer requires a remarkable huge CFD model.


  • Engine intake: Mach number contours in the S1 plane

  • Mach number contours in the S2 plane

  • High quality structured meshing up to farfield distance

  • Global installation situation (canopy removed)

Design of an aerodynamic robust and low loss engine intake for UAV helicopter applications. The complex freeform design is developed in a CAD system and is then meshed with fully structured blocks of intake, canopy and farfield. CFD simulations of the flight conditions hovering, max. forward flight and crosswind are carried out. The results are evaluated for further design optimizations to improve losses and flow control. Impacts on compressor performance due to inlet distortions are also assessed in a steady simulation.


  • Exhaust duct: Design of a complex flow geometry for small installation spaces

  • Automated blockstructured meshing

  • Optimized flow deceleration and pressure rise

Exhaust duct design for a small scale turboshaft engine. The challenging task is to design a low loss diffusor, which is splitted into two exits and bends around 90 degrees. The highly adaptable geometry generation is fully parameter based in aero_designworks design environment.