Secondary Flows in Turbomachines
Abstract
Improvement of the theoretical calculation of the inviscid core of the high performance turbomachines are more and more demanding the better understanding of the secondary flows, i.e. the part of the flow field that is close to the inner or the outer walls and is therefore subjected to high viscous stresses as well as to the effect of the vortices induced by the blade-casing junction. The meeting was divided into four sessions - a total of fifteen invited papers and seven short presentations - followed by a round table discussion. Representatives from industry made clear: - why up to now they were not able to use the theoretical approaches available in the literature; - the need for a theoretical estimation of the blockage factor to help them to calculate more correctly the low-loss core of the flow; - the need for correct loss estimation formulas. The response from research workers suggested: - simplified secondary vorticity considerations and pseudo-boundary layer approaches seem to be promising for multistage compressor analysis if backed by experimental results; - this analysis seems to be inadequate for turbines and fully three-dimensional calculation methods must be used. These are still time consuming but are certainly less expensive than experiments; - new experimental techniques must be used, in spite of cost and effort, to provide the necessary flow models. However, experiments must be carefully planned; - lack of understanding and experimental information exists in the areas of multistage environment, tip clearance effects and radial machines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA047370
Entities
Organizations
- AGARD