An Exact Linear Lifting-Surface Theory for a Marine Propeller in a Nonuniform Flow Field

Abstract

The mathematical model used in previous Davidson Laboratory adaptations of linearized unsteady lifting surface theory to marine propellers has been revised by removing the so-called 'staircase' approximation of the blade wake and replacing it by an 'exact' helicoidal blade wake. A new numerical procedure and program based on the present model has been developed to evaluate the steady and unsteady blade loading distributions, which are used to determine the bearing forces and moments. Systematic calculations of these forces and moments for a series of propellers show better agreement on the whole with experimental measurements than did the earlier calculations for the same series. In addition, the chordwise loading distributions are much smoother than obtained previously. However, the quantitative improvement must be weighed against the considerable increase in computer time over the old method.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1972
Accession Number
AD0742455

Entities

People

  • M. R. Ali
  • S. Tsakonas
  • William Jacobs

Organizations

  • Stevens Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Bending Moments
  • Bessel Functions
  • Computer Programs
  • Computers
  • Hydrodynamics
  • Hydromechanics
  • Integral Equations
  • Kernel Functions
  • Lifting Surfaces
  • Marine Propellers
  • Mathematical Models
  • Measurement
  • Nonuniform
  • Nonuniform Flow
  • Propeller Blades
  • Ships
  • Steady State

Fields of Study

  • Physics

Readers

  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Aerodynamics.