Design of an annular contraction
Abstract
The function of a contraction is to accelerate the flow velocity from a very low value in the settling chamber to the desired value in the test section and reduce the turbulent velocity components. An ideal contraction should provide the desired velocity distribution in the test section and should be of reasonably short length. Testing the compressor and turbine blades in an annular cascade tunnel can be done by establishing a rotating flow of constant angular momentum entering the test section for which the swirl vanes should be placed upstream of the test blades and in a region of low velocity. No satisfactory method is available for contraction design. Models based on tentative designs were made and the flow was analysed both experimentally and theoretically. This paper discusses the design and analysis of the flow through contraction models and the results obtained therefrom. It is found that the contraction with slanting walls of the bellmouth and centrebody, and with large contour radii gives a better performance.
- Publication:
-
Indian Journal of Mechanical Engineering Division
- Pub Date:
- September 1979
- Bibcode:
- 1979InJME..60...29S
- Keywords:
-
- Annular Flow;
- Channel Flow;
- Contractors;
- Flow Distribution;
- Flow Velocity;
- Potential Flow;
- Boundary Layer Flow;
- Cascade Flow;
- Centerbodies;
- Hubs;
- Pressure Measurement;
- Three Dimensional Flow;
- Turbine Blades;
- Uniform Flow;
- Velocity Distribution;
- Fluid Mechanics and Heat Transfer