| Popis: |
Measurements are reported of premixed hydrogen-air turbulent burning velocities, made by the double kernel method during explosions. Turbulence was created by four high speed fans within the explosion vessel. The method is described for calibrating the system, which is capable of giving high values of turbulent Reynolds numbers. The values obtained are compared with those of many other workers, over a wide range of burning conditions, mixtures and turbulent parameters. The ratio of turbulent to laminar burning velocity correlates well with both the turbulent Reynolds number and the ratio of laminar burning velocity to r.m.s. turbulent velocity. The use of hydrogen-air mixtures has extended the data on premixed turbulent combustion to regimes with higher values of the last dimensionless ratio. At high values of the ratio there is evidence of a wrinkled laminar flame structure, but at lower values a small scale eddy structure seems to be dominant. There is discussion on these findings, which accord with theoretical expectations. |
