Modern gas turbines have to meet the highest requirements in terms of environmental compatibility and economic efficiency. Reducing specific fuel consumption is of central importance and can be achieved by increasing the pressure build-up per stage. Another possibility is to reduce the number of blades within a stage. Both approaches increase the aerodynamic load on the compressor blades.
Conventional compressor blades are thus pushed to the limit. Due to the large positive pressure gradient in the rear area of the blade, the boundary layer grows strongly, the flow can no longer follow the profile contour and detaches. A high increase in losses and a collapse of the pressure build-up are the result. Tandem blades can provide a remedy here. On tandem blades, the flow at the rear blade is re-energised by the resulting slot flow and a new, thinner boundary layer is formed.
The project "Aerodynamics of Tandem Stators", which was successfully carried out at the department, dealt with two side-fixated stators. In the project "Aerodynamics of Tandem Stators II", the influence of the tip clearance on the flow field and the developing secondary flow field is being specifically investigated. This gives the already complex flow structure yet another influencing factor that affects the flow pattern, loss development and deflection distribution of the blade.
The research task was given by the FVV (The Research Association for Combustion Engines eV). The research project was carried out in the framework of the industrial collective research programme (IGF no. 19268 N). It was supported by the Federal Ministry for Economic Affairs and Energy (BMWi) through the AiF (German Federation of Industrial Research Associations eV) based on a decision taken by the German Bundestag.
Person of contact: M.Sc. Liesbeth Konrath
Funded by the Federal Ministry for Economic Affairs and Energy (BMWi)/ Task by the Research Association for Combustion Engines eV, 2017/2021