Self-ignition and special features of flow in a planar vortex chamber

Regular self-ignition of hydrogen and kerosene was registered upon their mixing with oxygen-enriched air in a straight-flow vortex, chamber of planar-radial geometry. These fuel components were injected into the chamber from tanks with room temperature and pressure 4–10 MPa. The velocity, pressure, and temperature fields in the chamber were studied using experimental methods and numerical modeling on the basis of full Navier–Stokes equations. The measurment and calculation showed that a region of elevated temperatures appears in an unsteady vortex flow. The calculation was performed for Reynolds number up to 5 $\cdot$ 10$^3$ and revealed an increase in temperature with increase in Reynolds number. Nevertheless, both the calculated and measured temperatures were lower than the known self-ignition temperatures. The nature of the ignition, observed remains unclear.