An existing computerized method for optimum design of waterjet propulsion systems for sub-cavitating hydrofoil craft is analyzed for sensitivity to variations in normally fixed parameters and for sensitivity to variations in the starting points for the search used in the optimization procedure. A compatible method for off design evaluation of waterjet propulsion systems is developed and incorporated into the optimization program in a manner which permits off design evaluation to be performed separately or in conjunction with design. The evaluation routine requires that system geometry, craft characteristics and pump characteristics be specified. System drag and losses are calculated to determine required flow rate and pump head and the corresponding pump speed, efficiency and required power are determined. Results of design optimization for a series of similar craft are presented and show a strong sensitivity to the input estimate of the take-off drag. Sensitivity to starting values of the independent variables was noted in some cases and appears to be due to the fact that jet velocity ratio dominates the other independent variables as an influence on total system weight. A FORTAN computer listing and sample inputs and outputs for both design and evaluation routines are included.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139
  • Authors:
    • Kruse, D K
  • Publication Date: 1973-6

Subject/Index Terms

Filing Info

  • Accession Number: 00048386
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Report/Paper Numbers: MS Thesis
  • Files: TRIS
  • Created Date: Nov 14 1973 12:00AM