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Forschung im Ingenieurwesen

, Volume 63, Issue 9, pp 263–269 | Cite as

Velocity measurements in a strongly swirling natural gas flame

  • A. Kremer
  • E. P. Hassel
  • J. Janicka
Article

Abstract

The present study was focused on the turbulent velocity field of a central annular natural gas jet which penetrated a strongly swirling air flow. Due to the high swirl number S=0.95 and the high momentum ratio, the fuel jet was almost immediately integrated into the air stream. High rates of shear resulted in an intensive turbulent mixing process between natural gas and air. The central hub of the fuel exit annulus stabilized the reverse flow zone at a fixed location. The present nozzle configuration resulted in a very stable and symmetric flame.

Keywords

Shear Zone Shear Layer Vortex Breakdown Swirl Number Burner Exit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols

b

width of fuel nozzle annulus

d

diameter

D

diameter, without index: air nozzle, 60 mm

f

focal length

I

momentum ratio

L=Qair/Qair,st

air ratio

m=ds/ds,0

magnification factor of beam expander

P

thermal power

Q

Volume flow rate in normcubicmeters per hour

Re

Reynoldsnumber, based on equivalent diameter

u

axial mean velocity

v

radial mean velocity

w

circumferential mean velocity

t

time

u′=√u2

standard deviation of mean axial velocity

v′=√v′2

standard deviation of mean radial velocity

w′=√w′2

standard deviation of mean circumferential velocity

x

axial direction (along axis of symmetry)

r

radius

λ

wavelength of laserlight

Superscripts

time aver. mean quantity

Indices

a

outer diameter

air

combustion air

b

blue colour

f

fuel: Natural Gas

g

green colour

i

inner side

l

lens

p

seeding-particle

s

laser-beam

s, 0

laser-beam before beam expansion

st

stochiometric mixture of fuel and air

th

thermal

Geschwindigkeitsmessungen in einer stark verdrallten Erdgasflamme

Zusammenfassung

In der vorliegenden Arbeit wird das Geschwindigkeitsfeld einer stark verdrallten Erdgasflamme vorgestellt. Es bildet die Basis für die intensive turbulente Durchmischung zwischen Brennstoff und Verbrennungsluft, die für Drallflammen charakteristisch ist. Aus einem zentralen Ringspalt tritt Erdgas aus und wird sofort in den stark verdrallten Luftstrahl integriert. Die Flamme stabilisiert sich nahe über dem Brenneraustritt und brennt symmetrisch. Als Meßdaten werden Mittelwerte für Axial- und Umfangsgeschwindigkeit zur Verfügung gestellt, sowie die Standardabweichungen und die Reynolds-Stress-Tensor Komponenten des Geschwindigkeitsvektors. Aufgrund der Kleinheit der mittleren Radialgeschwindigkeit werden diese Meßdaten nicht gezeigt. Die vorgestellten Ergebnisse dienen als Basis zur Validierung von Turbulenzmodellen.

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Copyright information

© Springer-Verlag 1997

Authors and Affiliations

  • A. Kremer
    • 1
  • E. P. Hassel
    • 1
  • J. Janicka
    • 1
  1. 1.Fachgebiet Energie- und KraftwerkstechnikTechnische Hochschule DarmstadtDarmstadtGermany

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