FULL SCALE EVALUATION OF WATERJET PUMP IMPELLERS

Full scale experiments were conducted with a U. S. Navy waterjet-powered planing boat to evaluate three different waterjet impeller/nozzle configurations. The configurations consisted of the standard impeller/nozzle combination currently installed on these craft in addition to a newly designed impeller evaluated with two different diameter nozzles. The overall program objective was to determine if marine propeller design techniques can be applied to the design of waterjet impellers and thereby (impeller) efficiency. Results show that the waterjet with a newly designed impeller approached but did not meet or exceed the overall performance of the waterjet equipped with the standard impeller and nozzle. The inlet velocity measurements showed extreme local velocity variations in flow approaching the impeller suggesting that any improvement in the impeller would have a marginal improvement on overall performance of the waterjet. It is concluded that marine propeller design techniques cannot be practically applied to the design of waterjet impellers in the majority of waterjets where extremely high thrust (disk loading) conflicts with the moderately-loaded propeller theory upon which the design procedures are based.

• Corporate Authors:

  David Taylor Naval Ship R&D Center

  Ship Performance Department
  Bethesda, MD  United States  20084
• Authors:
  • Alder, R S
  • Denny, S B
• Publication Date: 1977-9

Media Info

• Pagination: 52 p.

Subject/Index Terms

• TRT Terms: Boats; Cavitation (Mechanics); Culvert inlets; Diameter; Flow; Jet pumps; Nozzles; Performance; Propellers; Rotors; Seas; Shape; Testing; Variables; Velocity; Water pumps; Waterjet propelled craft; Waterjets
• Uncontrolled Terms: Configuration; Flow rate
• Old TRIS Terms: Axial flow; Duct inlets; Propeller theory; Sea testing; Variations; Waterjet propulsion; Waterjet pump performance
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00169439
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: SPD-718-02
• Files: TRIS
• Created Date: Mar 14 1978 12:00AM