RDE simulation

Case description• Flow solver: 2nd order, HLLC

• Chemistry solver: DVODE

• Species considered H2, O2, N2, H2O

• Combustion mechanism:

2 H2 + O2 = H2O + H2O

A=2.0E17, n=0.0, Ea = 12 000, in: cal, mole, cm, s unit system

• Computational domain consists of 160x20x450 (1.44 mln) cells

RDE simulation

GeometryDimension

Outer diameter 95 mm

Inner diameter 75 mm

Gap size 4 mm

Working part length 80 mm

Overall length 140 mm

RDE simulation

Inlet conditions Outlet conditions

• Total pressure inlet

– Vaxial = 76.2 m/s

– Vcircular = 100 m/s

– P = 10.6 bar

– T = 300 K

– Composition: H2/Air, φ = 0.5

• Extrapolated outlet

– Vaxial = 0 m/s

– Vcircular = 0 m/s

– P = 0.5 bar

– T = 300 K

– Composition: N2/H2O

Ignition parameters

– T = 2 000 K

– Vcircular = 500 m/s

Contours of H2 concentration, iso-surfaces of pressure; t = 4 microseconds

RDE simulation - ignition

Solution

• Solution is stabilized

after 700 - 800

microseconds

• 9 rotating detonation

waves occured

• Propagation speed of

each wave is equal

RDE simulation – solution

Contours of temperature, iso-lines of pressure

RDE simulationPressure iso-surfaces, t = 2 microseconds

Contours and iso-lines of temperature Contours and iso-lines of pressure

RDE simulation - results

RDE simulation - results

RDE simulation

Sensor data

• Collected from 9 points at the outer

surface of the engine model

• Time between two following peeks is 17

microseconds

• Each detonation waves circulates the

chamber in 171 microseconds

• Thus, the calculated circular velocities of

detonation waves are:

– Vouter = 1745.2 m/s

– Vinner = 1377.9 m/s

• The avarage speed:

– Vavarage = 1561.6 m/s

• Chapman-Jouget velocity for these

conditions:

– VC-J = 1586 m/s

RDE simulations - conclusion

• Streamtraces at the exit

are nearly axial despite

the high speed of

detonation propagation