"3D Nozzle": Compressible Flow with Shock, Transition, Turbulence and Unsteadiness

Research Area: Fluid mechanics
Project Members:
Alfredsson, P.H.
Sigfrids, T.
Tillmark, N.T.

Project Description

The object of the project is to enhance the fundamental physical understanding of compressible flow with shock, transition, turbulence and unsteadiness. The application of the basic research is aimed towards prediction models, which can be used towards solving industry-relevant problems of various types. The project involves several elements in a 3D viscous compressible flow environment: - Overall flow measurements in a nozzle at sub- and transonic speeds. - Detailed boundary layer measurements. - Applying modern measurement techniques (hot-wire, LDV, PIV) to compressible viscous flow. - Development of a new measuring technique towards time-dependent pressures. - Implementation, development and test of advanced transition/turbulence models into a general purpose Navier-Stokes solver from an overall perspective. The highly complex flow conditions found in most energy-conversion components will be significantly simplified for the purpose of the research study, while retaining most of the fundamental and essential flow features present in such components. Experiments will be performed on a nozzle test facility, in which two- and three-dimensional bumps are inserted. These models will represent several complex flow phenomena appearing in energy-converting components. The test section allows also for a time-dependent variation of the flow. The modular design of the test facility will provide testing possibilities of new sensor technology in compressible flow. Modern techniques as pressure sensitive paint and shear stress sensitive liquid crystals will also be tried out to be able to map the pressure distribution at the model surface. Numerical predictions will be performed on the model object using Reynolds-averaged Navier-Stokes codes. The comparison between experimental and numerical results will serve as an aid for the development of basic models related to boundary layer transition and separation in a complex compressible flow environment. The research project will include four graduate students, each with a distinct responsibility and research task. Collaboration between fundamental and applied research groups, as well as between research groups at different universities in Sweden, will greatly improve the progress of the research and be a fruitful experience for all graduate students involved in the project. The experimental parts will take place at KTH. The significant industrial perspective of the underlying physical phenomena will further enhance the students` experience. Four interdisciplinary TeknL. theses are expected to result from the project.

Publications related to the project


Internal Reports related to the project

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