Near-Body Velocity and Turbulence Measurements in the Lee of an Inclined 6:1 Prolate Spheroid

Abstract

Despite dramatic advancements in computing power over the last several decades, computational fluid dynamics (CFD) models have not yet replaced experiments as the primary design and verification tool for the development of air- and water-borne vehicles. The benefits of advanced computational tools include the ability to iterate rapidly on a design, predict a wide range of parameters to include forces and moments, wake characteristics and acoustics, allow for design optimization, all relatively inexpensively. Experiments, on the other hand, are often expensive and time-consuming to conduct, and generally offer results over a narrow range of parameters. However, when conducted carefully at an appropriate model scale, the results provide a measure of certainty that is not yet offered by computational models. To improve CFD models, a more nuanced understanding is required of the flow physics that they describe. To that end, experiments are to be conducted in the large recirculating water channel at the U.S. Naval Academy. The flow in the near-body region of a 6:1 prolate spheroid measuring 0.43 m (17 in.) in length will be examined for length-based Reynolds numbers of 1 to 3x1,000,000 at angles of inclination of 2.5 deg 5 deg,10 deg and 20 deg. Boundary layer trip designs will be evaluated and results compared to those of a smooth, un-tripped body. Velocity measurements will be made using a stereo particle image velocimetry (SPIV) system, with sufficient measurements taken to calculate mean flow and turbulence quantities. Results from this experiment will be made available for CFD verification and validation studies.

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Document Details

Document Type
Technical Report
Publication Date
Jul 12, 2021
Accession Number
AD1149678

Entities

People

  • Zachary D. Nygaard

Organizations

  • United States Naval Academy

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Boundary Layer
  • Boundary Layer Trips
  • Computational Fluid Dynamics
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Geometry
  • Hydrodynamics
  • Measurement
  • Mechanical Properties
  • Physics Laboratories
  • Reynolds Number
  • Three Dimensional
  • Turbulence
  • Water Tunnels

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Fluid Mechanics and Fluid Dynamics.