Section 6: Modeling Transient Rocket Operation

Material Taken from

1. Sutton and Biblarz: Section 6.1, Section 8.1, Chapter 11, Chapter 15, Appendix 4
2. Humble and Henry, " Space Propulsion Analysis and Design"
3. Richard Nakka Web Page: http://members.aol.com/ricnakk/th_pres.html
   
   
   
   
   Lecture1 Notes:................... (pdf )

• Transient Rocket Operation For Liquid Rocket Engines
  • Choking massflow
  • Chamber mass balance
  • Transient Combustor Pressure Model
  • Liquid Rocket Engine Model
    • Simplifications for Liquid Rocket
    • Design Rules for Combustor Dimensons
    • Combustor Characteristic Length, L*
    • Relationship of Combustor Contraction Ratio and Throat Diameter
    • "Effective Length" of Combustor
    • Propellant Massflow Rate:
      • Injector Equation for Incompressible Flow
      • Injector Equation for Compressible Flow
    • Oxidizer to Fuel ratio
    • Transient Start-up
    • Steady State Pressure
    • Tail-off Chamber Pressure
    • SSME example
    • Rocket Throttling
    • Throttling using Injector pressure
    • Issues associated with "deep throttling"
    • Pintle (Variable geometry) Injector
    • Applications of Deep Throttling Engines

• Transient response Model for Solid Rocket Motors
  • Effects of Changing Chamber Area and Volume
  • Propellant Burn Rate: Grain Recession and Saint Robert's Law
  • Effect of Chamber length and Burn Area
  • Transient Start-up, Tail-off Chamber Pressure
  • Space Shuttle RSRM example
  • Progressive/Neutral/Regressive Burn Patterns
  • Grain Shaping for burn control
  • RSRM with Modified (Regressive burn) grain pattern