lesson 6 principles of thermochemistry
Download
Skip this Video
Download Presentation
Lesson 6: Principles of Thermochemistry

Loading in 2 Seconds...

play fullscreen
1 / 17

Lesson 6: Principles of Thermochemistry - PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on

Lesson 6: Principles of Thermochemistry. Dr. Andrew Ketsdever. Propellants. Several Factors Must Be Addressed When Deciding on a Propellant Performance Chemical energy content, Achievable Isp Economics Availability, logistics of production and supply Physical Hazards

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Lesson 6: Principles of Thermochemistry' - naasir


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
propellants
Propellants
  • Several Factors Must Be Addressed When Deciding on a Propellant
    • Performance
      • Chemical energy content, Achievable Isp
    • Economics
      • Availability, logistics of production and supply
    • Physical Hazards
      • Stability, corrosiveness, carcinogens
liquid propellants
Liquid Propellants
  • Desirable Properties
    • Low Freezing Point
    • High Specific Gravity
    • Good Stability
    • High Specific Heat
    • Low Vapor Pressure (better pumping)
    • Easy Ignition (hypergolic?)
liquid propellants1
Liquid Propellants
  • Highest Potential Specific Impulse
    • Fluorine Oxidizer
    • Hydrogen Fuel with suspended Beryllium
    • Isp=480 sec at Po = 1000 psia (sea level)
    • Oxidizer highly corrosive (not storable)
    • Beryllium suspension can not be maintained uniformly
liquid propellants2
Liquid Propellants
  • Oxidizers
    • Liquid Oxygen
      • Boils at 90K
      • Heat of Vaporization 213 kJ/kg
      • High attainable performance
      • Does not burn spontaneously with hydrocarbons at ambient pressures and temperatures
      • Noncorrosive and nontoxic
      • Cryogenic temperature poses handling issues
liquid propellants3
Liquid Propellants
  • Liquid Fluorine
    • Boils at 53.7K
    • Highest values of performance (typically)
    • High specific gravity
    • Extremely toxic and corrosive
    • Poisonous exhaust gases
    • Low commercial consumption
    • Expensive
liquid propellants4
Liquid Propellants
  • Hydrogen Peroxide (H2O2)
    • Requires high concentration (70-99%)
    • Storage concerns
    • Decomposition with certain metal catalysts
  • Nitric Acid (HNO3)
    • Highly corrosive
    • Certain stainless steels and gold containers required
    • Skin burns
liquid propellants5
Liquid Propellants
  • Nitrogen Tetroxide (N2O4)
    • Most common storable oxidizer used in the US
    • High density
    • Relatively high freezing point
    • Mildly corrosive
    • Hypergolic with many fuels
    • High vapor pressure
    • Used with hydrazine (UDMH, MMH) propellants
liquid propellants6
Liquid Propellants
  • Fuels
    • Hydrocarbon Fuels
      • RP-1 (Kerosene-like)
        • Easy to handle
        • Cost effective
      • Methane (CH4)
        • Cryogenic (denser than liquid hydrogen)
liquid propellants7
Liquid Propellants
  • Liquid Hydrogen
    • Boils at 20K
    • Specific Gravity 0.07
    • Bulky fuel tanks, large volumes
      • Increased drag
    • Feed system must be cryogenic compatable
    • Increased insulation
    • Nontoxic products (typically)
liquid propellants8
Liquid Propellants
  • Hydrazine
    • Monomehtylhydrazine (MMH)
    • Unsymmetrical dimethylhydrazine (UDMH)
      • Toxic
      • High freezing point 274.3K (MMH) / 216K (UDMH)
      • Hypergolic with some oxidizers
      • Spontaneous ignition with air can occur
      • Positive heat of formation (good)
      • Good monopropellants with the right catalyst
      • Reasonable stability
solid propellants
Solid Propellants
  • Classes
    • Double Base Propellant: forms a homogeneous propellant grain of a nitrocellulose and a solid ingredient dissolved in nitroglycerin plus minor additives
    • Composite Propellant: form a heterogeneous propellant grain with the oxidizer crystals and a powdered fuel held together in a matrix of synthetic rubber binders.
      • Less hazardous than double base
solid propellants1
Solid Propellants
  • Oxidizers
    • Ammonium Perchlorate (NH4ClO4)
      • Most widely used crystalline oxidizer
      • Good performance
      • Good availability
    • Potassium Perchlorate (KClO4)
      • Medium performance
      • Higher density than AP
      • Low burning rate
solid propellants2
Solid Propellants
  • Fuels
    • Powdered Aluminum
      • 5-60 micron diameter
      • 14-18% of propellant by weight (typical)
      • Small particles can burn spontaneously in air
      • Oxide particles can agglomerate and form larger particles (two phase issues)
    • Other metallic fuels
      • Boron, Beryllium
solid propellants3
Solid Propellants
  • Binders
    • Hydroxy Terminated Polybutadiene (HTPB)
      • Binder provides the structure or matrix in which solid ingredients are held together (composite propellant)
      • Polymer, synthetic rubber
      • Primary effect on motor reliability, storability and cost
  • Other Additives can be included
    • Improve burn rate, storability, curing
hybrid propellants
Hybrid Propellants
  • Fuel and Oxidizer mixtures of liquid oxidizer and solid propellants (typically)
    • Combinations of propellants already discussed
    • Fuel: HTPB, PMMA, HS
    • Oxidizer: LOx, H2O2, N2O
nuclear propellants
Nuclear Propellants
  • Fuels
    • Low molecular weights
      • Hydrogen, Water, Methane
    • No chemical reactions necessary
ad