A generalized waterjet propulsion system in a subcavitating hydrofoil craft is considered for design and performance estimation. Independent system parameters of jet velocity ratio, inlet velocity ratio, and nacelle inlet diameter to maximum diameter ratio are varied to search for the optimum system. The optimum system is defined as the minimum total propulsion system weight. The optimization scheme utilizes a directed search without the calculation of derivatives, and was chosen for its simplicity, versatility and rapidity. The ducting system is divided into components for head loss calculations. For a given design, total head losses in the duct are computed by means of experimental data and empirical equations, enabling pump, reduction gear, and prime mover design to be completed. Results for a sample craft are included which indicate that hydrofoils should be designed about the gas turbine, due to the discrete power levels that are available. Suboptimizing the nacelle design may lead to an overall less optimum system design. A general lack of information was noted on nacelle, cascade corner, and three dimensional diffuser design and performance prediction. A FORTRAN computer listing and flow charts are included.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139
  • Authors:
    • Carmichael, A D
    • Gill, R P
  • Publication Date: 0

Media Info

  • Serial:
    • Issue Number: Pt 4

Subject/Index Terms

Filing Info

  • Accession Number: 00044154
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Report/Paper Numbers: Rpt 72-16
  • Files: TRIS
  • Created Date: May 11 1973 12:00AM