Accession Number : AD0439631


Title :   A METHOD FOR THE DESIGN OF PUMPJETS


Corporate Author : PENNSYLVANIA STATE UNIV STATE COLLEGE ORDNANCE RESEARCH LAB


Personal Author(s) : Henderson, R E ; McMahon, J F ; Wislicenus, G F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/439631.pdf


Report Date : 15 May 1964


Pagination or Media Count : 73


Abstract : The pumpjet - a hydrodynamic propulsor - is similar to a conventional propeller rotating within a ductor shroud. The shroud permits the flow velocity through the rotor to be controlled more or less independently of the velocity of the vehicle. For certain applications, the pumpjet can be designed to have better cavitation characteristics than an open propeller; alternatively, the pumpjet can be made smaller than the conventional propeller to reduce the weight of the propelling machinery. The pumpjet may be designed on the basis of knowledge and experience gained from axial-flow compressors and pumps. The meridional flow within the shroud is assumed to be axially symmetrical. The flow through the vane system is considered, with certain restrictions, to be cylindrical. Although axial-compressor data can be used for the blade design, blade profiles suitable for compressors are not suitable for hydrodynamic propulsors because of the stringent requirements regarding cavitation. A quasi onedimensional method of blade design is described that uses compressor data but still meets the cavitation requirements. Problems of shroud design, skewed vanes, unsteady force action, and boundary-layer intake are discussed; and problems that remain unsolved are also pointed out.


Descriptors :   *HYDROJET ENGINES , CAVITATION , FLUID FLOW , HYDRODYNAMICS , OPERATION , ROTOR BLADES(TURBOMACHINERY) , THEORY , VORTICES


Subject Categories : Jet and Gas Turbine Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE