Turbulent Nonpremixed Flames

• List five practical examples of turbulent diffusion flames in engineering.
• How do turbulent diffusion flames (nonpremixed flames) differ from turbulent premixed flames?
• How does flame length vary with:
  • stoichiometric mixture fraction
  • jet exit diameter
  • density ratio (exit to surroundings)
• How does a turbulent jet flame length vary with volumetric flow rate for a given jet exit diameter?
• What is the physical interpretation of the Froude number?
  • What physical process/consideration motivates its use?
• T/F: for a momentum controlled jet, the dimensionless flame length is independent of Fr.
• Does buoyancy tend to increase or decrease jet flame lengths?
• What is the typical length-to-width ratio for turbulent jet flames?
• What are theories for lifted flames?
• What three quantities does radiative heat loss primarily depend on?
• Describe how increasing turbulent mixing affects flame temperatures in terms of soot, radiation, and flame strain.