OPTIMIZATION OF PROPELLER SKEW DISTRIBUTION TO MINIMIZE THE VIBRATORY FORCES AND MOMENTS ACTING AT THE PROPELLER HUB

Propeller skew is now well recognized as a means of reducing the unsteady forces and moments produced by the propeller. The propeller skew design problem is formulated as an optimization problem to minimize a weighted, linear combination of the six vibratory forces and moments acting at the propeller hub. The skew distribution is taken as a cubic or quadratic function of radius subject to realistic geometric constraints. This allows the optimization to be economically solved using existing constrained, nonlinear mathematical programming or parameter optimization methods. The SKEWOPT propeller skew optimization program is described. This interactive program was developed to perform the propeller skew optimization in a routine design setting. The vibratory forces and moments are evaluated using either a two-dimensional, sinusoidal gust theory or a three-dimensional, unsteady, lifting-line theory. The optimization is performed by an external penalty function technique utilizing the Nelder and Mead simplex search. Design examples using the SKEWOPT program are presented to illustrate the use of the program and to validate the propeller skew design approach.

• Corporate Authors:

  University of Michigan, Ann Arbor

  Department of Naval Architects and Marine Engineers
  Ann Arbor, MI  United States  48109

  Maritime Administration

  Office of Maritime Technology, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Parsons, M G
  • Greenblatt, J E
• Publication Date: 1978-12

Media Info

• Pagination: 66 p.

Subject/Index Terms

• TRT Terms: Computer aided design; Computer programming; Computer programs; Force; Mathematical models; Propellers; Skewed structures; Structural design; Vehicle design; Vibration
• Uncontrolled Terms: Skewness
• Old TRIS Terms: Computer programs (Propellers); Lifting line theory; Marine propellers; Marine surface propulsion; Propeller design; Propeller hubs; Propeller induced forces; Propeller induced vibration; Skewed propellers
• Subject Areas: Design; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00198057
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: 206 Final Rpt., MA-RD-940-79023
• Contract Numbers: MA-7-38077
• Files: TRIS, USDOT
• Created Date: Sep 15 1979 12:00AM