Measurements of burning velocities of dimethyl ether and air premixed flames at elevated pressures

Laminar burning velocities of dimethyl ether (DME) and air-premixed flames at elevated pressures ≤ 10 atm were measured by using a newly developed pressure-release type spherical bomb. The measurement system was validated using laminar-burning velocities of methane-air flames. A comparison with the previous experimental data showed an excellent agreement and demonstrated the accuracy and reliability of the present experimental system. At 1 atm, the measured laminar burning velocities of DME-air flames were in reasonable agreement with the previous data from spherical bomb method, but were much lower than both predictions and the experimental data of the particle image velocimetry (PIV) based counterflow flame measurements. Flame speed decreased considerably with increasing pressure. At high pressures the rich DME-air flames were strongly affected by the hydrodynamic and thermal-diffusive instabilities. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004).