Assessing the Transient Gust Response of a Representative Ship Airwake using Proper Orthogonal Decomposition

Abstract

In an effort to better understand at-sea helicopter operations and improve flight envelope definition, this project analyzed the effects of transient wind gusts on a representative ship airwake. Existing meteorological data were combined with a Simple Frigate Shape 2 model undergoing translational oscillations in order to simulate full scale, sweeping gusts in a closed-circuit wind tunnel. The experiment modeled a spectrum of full-scale gust durations and wind direction oscillations ranging from 4 to 14 degrees. When scaled to testing conditions for a1:120 scale model, the test matrix included six separate data points at gust-frequency referenced Strouhal numbers ranging from 0.430 to1.474. A 725-Hertz time-resolved Particle Image Velocimetry system was then used to acquire flow field data across a series of three horizontal planes spanning from 0.25 to 1.5 times the ship hangar height. All testing was conducted at a steady-state, ship hangar height referenced Reynolds number of 26,000 which correlated to a tunnel velocity of approximately 25 feet per second.

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Document Details

Document Type
Technical Report
Publication Date
May 21, 2018
Accession Number
AD1054392

Entities

People

  • Christopher G. Cantillo

Organizations

  • United States Naval Academy

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aircrafts
  • Boundary Layer
  • Computational Fluid Dynamics
  • Flow Fields
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Navy
  • Reynolds Number
  • Strouhal Number
  • Three Dimensional
  • Turbulence
  • Turbulent Mixing
  • United States Naval Academy
  • Wind Tunnels
  • Wind Turbines

Readers

  • Control Systems Engineering.
  • Fluid Dynamics.
  • Naval Architecture and Marine Engineering.