Objective
Laminar to turbulent flow transition is an important aspect in turbomachinery flows. To gain a better understanding of the transition characteristics, measurements of the flow around 3 different types of leading edges (sharp, cylindrical and C4) were made. Hot wire and flow visualization techniques were used to observe and measure the velocity and turbulence characteristics of the flow. The effects of Reynolds number, free stream turbulence, velocity shear and leading edge geometry were studied extensively.
For the sharp leading edge case the effect of free stream turbulence is well predicted using correlations for turbulence intensity less than 6%. For higher turbulence intensities bypass transition takes place and correlations overpredict the position of the start of transition. For the cylindrical leading edge case laminar separation occurs close to 90 degrees from the stagnation point. The free shear layer enveloping the separation bubble becomes transitional and reattaches as turbulent boundary layer. The length of the separation bubble is a function of Reynolds number and free stream turbulence intensity. The C4 leading edge has a pressure distribution of the surface such that laminar separation is avoided. As a result flat plate data regarding transition are applicable for the C4 case.
In the case of mean velocity shear the separation bubble formed on the cylindrical leading edge is affected by both the Reynolds number and the shear rate. The separation point moves further downstream while the rear part of the separation bubble appears to be dependent only on the free stream turbulence intensity. Computationally the low Reynolds model developed by Launder and Sharma can predict adequately bypass transition. For the cylindrical leading edge the front part of the separation bubble is predicted adequately. The rear part of the bubble is dominated by the unsteadiness of the reattachment point and it is not predicted well.
Computational techniques of the flow around the leading edge will be validated and correlations for the transition point or modifications to turbulence models will be produced to improve the prediction of transition on turbomachinery blades.
The effects of coherent structures and mean velocity gradients on transition will also be observed and modelled.
Calibration and intercomparison of transition data from the wind tunnels available to the partners.
Validation and intercomparison of computer programmes available for, or developed by the partners to model the flow around the leading edge.
Measurements of the flow field and transition information on a flat plate as a function of Reynolds number, and leading edge geometry and for high free stream turbulence 4%-15% typical of the inlet to multistage turbomachine.
Measurements of the flow field and transition on a flat plate when the mean flow field has a velocity gradient normal to the surface.
Measurements of the flow field and transition on a flat plate when the uniform mean flow contains coherent structures, ie, longitudinal or transverse vortices which may even impinge on the edge. The frequency and scale of the vortices will be treated as a parameter of the study.
Development of correlations and modification to turbulence models in order to improve the capability of prediction of transition in turbomachinery blades.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- engineering and technology mechanical engineering vehicle engineering aerospace engineering aircraft
- natural sciences physical sciences classical mechanics fluid mechanics fluid dynamics
- natural sciences mathematics pure mathematics geometry
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Data not available
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
54006 THESSALONIKI
Greece
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.