DIFFUSION HYDROGEN MICROJET COMBUSTION (ROUND BEVELLED NOZZLE)

Read more The purpose of this work is experimental study of diffusion combustion of the round hydrogen microjet at the 45° bevelled nozzle. The new phenomenon is revealed during combustion of a given hydrogen microjet, which we have named «bottleneck», as well as in a situation of the round and plane microjet combustion. The special attention has been given to research of characteristics of the «bottleneck» development and its role during of a hydrogen round microjet combustion. It is shown, that «bottleneck» represents the closed spherical area of the hydrogen with air mixture combustion in a jet near-field. The «bottleneck» area is closed by a powerful density gradient. It is found, that the laminar hydrogen jet in this area overcomes a density gradient of gas, becomes turbulent and combustion process is accompanied both a turbulent jet, and a turbulent flame further downstream evolution. It is shown, that the spatial size of a «bottleneck» decreases with growth of a jet velocity. It is found, that shadow patterns of the microjet combustion obtained for two shooting positions (normal and side view to the bevelled nozzle) were identical.

Keywords:
round hydrogen microjet, hydrogen diffusion combustion, schlieren method, shadow patterns.
УДК 544.452.42

DIFFUSION HYDROGEN MICROJET COMBUSTION (ROUND BEVELLED NOZZLE)