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DUCTED PROPELLERS

Photograph of a marine ducted propeller

A ducted propeller is a propulsion device consisting of a conventional open propeller surrounded by a duct or nozzle. Ducted propellers find extensive applications in both marine and aeronautical fields. The duct surrounding the propeller may be used either to accelerate or to decelerate the flow in the propeller plane. In marine applications the flow accelerating duct is known as the "Kort Nozzle" and the flow decelerating device is generally referred as the "pump-jet"

The concept of surrounding the propeller by a shroud is very old. Kort Nozzle ducted propellers have been widely used in tugboats and trawelers where the propeller is small and heavily loaded. The advantage of using a ducted propeller for these vessels is that the flow is accelerated and thus an improvement in propulsive efficiency is obtained In addition the duct shares a fair proportion of the thrust and thereby reduces the propeller loading. The flow accelerating pump-jets find considerable applications for the propulsion of submarines and torpedoes since the lower velocity in the propeller plane helps to delay the cavitation induced noise. The duct itself however will produce a negative thrust.


Table 1

  J Tau CT KTD CTD
NSMB Expt 0.4321 0.7470 3.5090 0.065 0.8897
Ryan/Glover Theory 0.4321 0.7790 3.3700 0.0546 0.7454
Gibson/Non Iterative 0.4321 0.7790 - 0.0610 0.8350
Gibson/Iterative - 0.7560 - 0.0627 0.8550
Vortex Element Method - Iterative - V. Balabaskaran 0.4321 0.7470 3.5090 0.0633 0.8637

Comparison of measured and predicted duct thrusts

 


Aerodynamic Studies on Kort Nozzle Ducted Propeller Aerodynamic studies of a Kort Nozzle Ducted Propeller


DUCTED PROPELLER

BIBILIOGRAPHY ON DUCTED PROPELLERS

  1. Bagley. J.A., Kirbyr N.B., Mareer, P.J.'A Method Calculating the Velocity Distribution on Annular Aerofoils in incompressible flow, 'ARC Technical Report, R and M No. 3146 (1961).

  2. V. Balabaskaran, 'Aerodynamic Investigations of a Ducted Propeller', Ph.D. Thesis, Department of Mechanical Engineering, IIT, Madras, India (1982)

  3. Young, C., 'An Investigation of Annular Aerofoils for Turbofan Engine cowls,' RAE Technical Report 69285 (1969).

  4. Lewis. R.I., 'Ducted Propeller Propulsion Systems,' Internal Report Tb 15, Department of Mechanical Engineering University of Newcastle Upon Tyne (1971).

  5. Lewis, R.I., 'Fluid Dynamic Design and Performance Analysis of Ducted Propellers,' Trans. Of North East Coast Institution of Engineers and Shipbuilders. Vol.88 (1972).

  6. Sacks. A.H., Burnell. J.A., 'Ducted Propellers - A Critical Review of the state of Art'. Progress in Aeronautical Sciences. Vol-3 (1962), pp 85-135, Pergamon Press.

  7. Weissinger. J., Maass, D., 'Theory of Ducted Propellers - A Review,' 7th Symposium on Naval Hydrodynamics, Rome. (August 1968) Office of Naval Research, Department of U.S. Navy.

  8. Morgan, W.B., Caster. E.B. 'Comparison of Theory and Experiment on Ducted Propellers,' 7th Symposium on Naval Hydrodynamics. Rome,(August 1968), Office of Naval Research Department of U.S. Navy.

  9. Weetman, R.J., Cromack, D.E., 'Ducted Propellers A Review and Description of Current Investigation,' University of Massachusetts. Report No. THEMIS-UM-70-l., (January 1970).

  10. Kuchemann., D., Weber, J., 'Aerodynamics of Propulsion,' Mc Graw Hill Publishing Co. Ltd. London (1957).

  11. Hess, J.L. and Smith, A.M.0., 'Calculation of Potential Flow about Bodies., Progress ' Aeronautical Sciences, Vol.8 (1967) pp 1-138.

  12. Lewis, R.I., Ryan, P.G., 'Surface Vorticity Theory for Axi-symmetric Potential Flow Past Annular Aerofoils and Bodies of Revolution with Application to Ducted Propellers and Cowls ' Jour. Mech.Engg. Sci., Vol.14p No.4 (1972).

  13. Ryan, P.G., Glover, E.J., 'A Ducted Propeller Design Method: A New Approach Using Surface Vorticity Distribution Techniques and Lifting Line Theory,' Trans. RINA, Vol.144, (1972).

  14. Gibson, I.S., Lewis, R.I., 'Ducted Propeller Analysis by Surface Vorticity and actuator disc theory', RINA Symposium on Ducted Propellers, Paper No. 1 (1973)

  15. Glover, E.J., 'Design Method for the heavily Loaded Marine Propeller' Trans. RINA, Vol. 116 (1974).

  16. Ryall, D.L., Collins, I.F., 'Design and Test of A Series of Annular Aerofoils,y' ARC R and M No. 3492 (March 1965).

  17. Van Manen, J.D. 'Open Water Test Series with Propellers in Nozzle,' Inst. Shipb. Progress, Vol.4, No.3 (1954).

  18. Van Manen. J.D "Recent Research on Propellers in Nozzles ' Inst. Shipb. Progress, Vol.4, No. 36. (1957).

  19. Van Manen, J.D., 'Effect of Radial Load Distribution on the Performance of Shrouded Propellers,' Int. Shipb. Progress. V01.9, No.93 (May 1962) pp 185-196.

  20. Van Manen, J.D., Superina. A., 'The Design of Screw Propellers in Nozzles,' Int. Shipb. Progress, Vol.6. No.55 (March 1959) pp-95-113.

  21. Emersen, A. Sinclair, L., 'Experimental and Practical considerations in the design of a Ducted Propeller System,' RINA Symposium on Ducted Propellers (1973).

  22. Lewis. R.I.. 'Turbomachinery Fluid Dynamic Problems and Techniques - A Review of some Recent Research,' Keynote Address,, Eighth National Conference on Fluid Mechanics and Fluid Power, Coimbatore,, InIia (1978).

  23. Ryan, P.G., 'Surface Vorticity Distribution Techniques Applied to Ducted Propeller Flows', Ph.D. Thesis, Dept of Mech. Engg., University of Newcastle Upon Tyne (November 1970).

  24. Lewis R.I., 'A Theory for Prediction of the Off Design Performance of Kort Nozzle Ducted Propellers,' Internal Report No. Tb 219 Department of Mechanical Engineering, University of Newcastle Upon Tyne (August 19i2).

  25. Gibson, I.S.,'Application of Vortex Singularities to Ducted Propellers,' Ph.D. Thesis, Newcastle Upon Tyne (October 1972).

  26. Oosterveld, M.W.C., 'Wake adapted Ducted Propeller,' Publication No 345, Netherlands Ship Model Basin, Wageningen (June 1970).

  27. Jacobson, G.N., Discussions on the paper 'Experimental and Practical Considerations in the Design of a Ducted Propeller System', RINA Symposium on Ducted Propellers', Paper No.2, (1973).

  28. Turbalt V.K., 'Theoretical Solution of the Problem on the Action of a Non-axisymmetrical Ducted Propeller System in a Non-Uniform Flow,,' RINA m.posium on Ducted Propellers, Paper No.2 (1973).

  29. Hill, V.P., 'Surface Vorticity Theory for Propeller Ducts and Turbofan Engine Cowls in Non-Axisymmetric ':Incompressible Flow,' Jour. Mech.Engg.Sci, I.Mech.E. Vol.20, No.4 (1978) pp 201-217.

E-mail: vbala@iitm.ac.in

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Updated on 11 Sep 2001