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Project information
Project description
Modern stability prediction methods and control.
| Research area: |
Fluid mechanics |
| Project members: |
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| Sponsor: |
FOI
KTH
STEM
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Project description
The project concerns a new transition prediction tool which is being developed in cooperation with DLR in Gottingen. The code uses the parabolized stability equations (PSE) and is so far based on the linearized equations. The method uses a wave ansatz with a slowly varying amplitude function
and wave number, similar to the WKB method. In addition an auxiliary condition is introduced which ensures uniqueness of the solution so that the traditional WKB expansion can be avoided. This method has proven to be e±cient and to produce accurate stability results for complicated glows. It has been carefully checked against existing solutions and will be extended to handle non-linear interactions between wave components.
Applications motivating the development of this method is the hypersonic transition research carried out within the ESA FESTIP program and laminar wing design carried out in the CEC EUROTRANS and ALTTA programs.
Another direction in this research is to use optimization methods to predict the transition location in flows with high free-stream turbulence levels. This is done using adjoint methods, similar to those used in the active control project, and parabolic approximations for the stability problem. A new transition prediction method has been proposed. The later stages of transition induced by high free-stream turbulence levels have been studied using secondary stability analysis.
Related articles published in journals or conference proceedings
Internal reports
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