PRELIMINARY INVESTIGATION OF AN UNDERWATER RAMJET POWERED BY COMPRESSED AIR

Abstract

Thrust, inlet pressure, and mixing-chamber pressure were determined at speeds between 20 and 60 feet per second for a hydroduct or underwater ramjet with a maximum diameter of 3.2 inches and a fineness ratio of 5.9, powered by compressed air (0.1 to 0.3 pound per second). Maximum efficiency was approximately 53 percent at a thrust coefficient of 0.10. The force and pressure coefficients were functions primarily of the ratio of airflow to free- stream velocity. Performance may have been influenced by choking of the exit. A theoretical development of the underwater ramjet cycle was made, with the assumption that the air-water mixture can be treated as a compressible gas. A method is suggested for including the effect of choking. An exploratory calculation indicated the effect of choking was minor.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1961
Accession Number
AD0268736

Entities

People

  • Charles J. Shoemaker
  • Elmo J. Mottard

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Air Force Facilities
  • Coefficients
  • Compressed Air
  • Compressible Flow
  • Diffusers
  • Dynamic Pressure
  • Flow
  • Fluid Dynamics
  • Fluids
  • Free Stream
  • Incompressible Flow
  • Mass Flow
  • Measurement
  • Model Basins
  • Pressure Measurement
  • Static Pressure
  • Subsonic Diffusers

Readers

  • Combustion and Flow Dynamics.