[vikram]

Hello all,

I was wondering if anybodycould help me with the simulation of detonation in a hydrogen-fueled detonation (pulse) engine using fluent. I am not able to get the required pressure spike for my model. The following are its technical specifications:

The ambient conditions outside the tube are assumed to be 1 bar and 298 K. A high-pressure, high-temperature driver gas (driver pressure, pdriv = 30 p0, and driver temperature, Tdriv = 2500 K) consisting of water vapour is used in a small region next to the closed end of the tube (length of driver gas, Ldriv = 0.005 Lt).

I used Fluent's patch option to patch the driver (H2O) and driven gas (fuel mixture) zones in the cylinder. I am not getting the required pressure spikes for a detonation, though the mixture seems to undergo combustion. I am using a stoichiometric hydrogen-oxygen fuel mixture for simplicity along with inviscid flow conditions. I don't seem to be getting a DDT, though the paper I read guarantees a detonation for the above conditions. Is there something wrong with my species definition? Should I rather use a pressure based solver with a spark ignition system? What reaction mechanism does Fluent use for hydrogen-oxygen combustion? The paper had used a Jachimowski reaction mechanism (23 reactions in all). Do I have to set ignition conditions for the mixture based on what mechanism Fluent uses?

I would really appreciate it, if anybody could kindly help me. Thank you for your time.

Sincerely,

Vikram.