Product Recirculation

1
Product Recirculation Mixing Measurements in
SPRF Combustor

• Mohan Bobba
• Karthik Periagaram
• 09-19-2006

2
Product Recirculation Mixing Measurements

• Flame stability enhanced due to
• Low velocity/High turbulence
• Recirculation of hot products
• Increase in OH PLIF signal before the sharp
  gradients (flame)
• Measurement of product entrainment in both
  premixed/non-premixed modes
• Spontaneous Raman Scattering

3rd Quarter
3
Spontaneous Raman Scattering - I

• Measures concentrations of major species
• N2, O2, CH4, CO2 and H2O

4
Spontaneous Raman Scattering - II
5
System of Equations
6
Mixing Studies using Raman Scattering

• Premixed system
• Product-reactant mixing
• Non-Premixed system
• Need addition parameter to characterize fuel-air
  mixing mixture fraction

Premixed CH4 Air System
7
Premixed CaseCentre line
8
Mean Axial Variation of Xi and T Premixed Case
(Centre line)
9
Histograms of Xi and T Premixed
10
Conditional Mean Axial Variation of Xi and T -
Premixed
?Xi mean (Xi ? XCH4 gt 0.1 XoCH4)
11
Burning Equivalence Ratio - How lean??
12
Product Entrainment - Premixed
fstoich 0.0551
finj 0.033
13
Non-Premixed CaseCentre line
14
Mean Axial Variation of Xi and T Non-Premixed
Case (Centre line)
15
Histograms of Xi and T Non-Premixed
16
Non-Premixed CaseOff Centre line
17
Mean Axial Variation of Xi and T Non-Premixed
Case (Off Centre)
18
Histograms of Xi and T Non-Premixed
19
finj 0.033
fstoich 0.0551
Mean Axial Mixture Fraction Variation
20
finj 0.033
fstoich 0.0551
21
finj 0.033
fstoich 0.0551
22
Mixture Fraction and Product Recirculation
23
Future Plan

• Scaling Issues
• Variation in Combustor Length and Diameter
• Injector size 1 dia
• Air leakage issues PLIF/Raman data
• Side injection flow visualization
• Product recirculation and Mixing studies

24
(No Transcript)
25
(No Transcript)
26
fstoich 0.0551
fstoich 0.033
27
finj 0.033
fstoich 0.0551
28
Mean Axial Variation of mole fractions and
temperature for Premixed (P), Non-Premixed Center
(NPC) and Non-Premixed Off-Center (NPOC)
Conditional Cases
29
Mean Axial Variation of mole fractions and
temperature for the Non-Premixed Center
Conditional Case
30
Mean Axial Variation of mole fractions and
temperature for the Non-Premixed Off-Center
Conditional Case
31
fstoich 0.0551
fstoich 0.033