ACOUSTIC LOSSES OF A SUBSCALE, COLD-FLOW ROCKET MOTOR FOR VARIOUS 'J' VALUES

Abstract

Acoustic dissipation studies were undertaken using a subscale, cold- flow rocket motor model to determine the effect of purely geometric variables on the acoustic performance leading to axial mode combustion instability. Cold air served as the working fluid to simulate the internal flow and to obtain a critical nozzle throat condition. Using interchangeable metal parts, it was possible to simulate the geometry of a cylindrical-bore grain at various real motor burn times and also to vary the nozzle throat diameter. The results confirmed the speculation that, for practical motor designs, the radiation of acoustic energy through the nozzle is the largest source of loss for the axial mode and increases with the J of the motor. In view of the change in J with time during burning, this loss can vary conspicuously during the motor burn time.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1966
Accession Number
AD0628896

Entities

People

  • E. W. Price
  • F. G. Buffum
  • G. L. Dehority
  • R. O. Slates

Organizations

  • Naval Air Weapons Station China Lake

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Velocity
  • Air Supplies
  • Attenuation
  • Combustion
  • Control Systems
  • Creep
  • Flow Rate
  • Heat Transfer
  • Human Factors Engineering
  • Materials
  • Measurement
  • Oscilloscopes
  • Pressure Regulators
  • Propellants
  • Radiation
  • Resonant Frequency
  • Waveforms

Fields of Study

  • Physics

Readers

  • Mathematics or Statistics
  • Rocket Propulsion.
  • Theoretical Analysis.