Calculation model of ignition temperature of high temperature titanium-aluminum alloy for aeroengine

The ignition temperature serves as a pivotal parameter for assessing the flame retardancy of high-temperature titanium aluminum alloys（TiAl alloys）. Nevertheless, accurately predicting the ignition temperature of TiAl alloys remains a formidable challenge. Leveraging the Frank-Kamenetskii and Coulomb friction models, this paper develops a computational framework to determine the critical ignition temperature of TiAl alloy. It further investigates the influences of flow velocity, friction contact pressure, and oxygen partial pressure on this critical temperature. The findings reveal that as the flow velocity escalates from 140 m/s to 340 m/s, the critical ignition temperature incrementally rises from 1699.0 K to 1751.6 K. Intriguingly, while friction contact pressure increases from 1.0 MPa to 3.9 MPa, the critical ignition temperature stabilizes at 1710.2 K; however, the threshold ambient temperature necessary for alloy combustion decreases linearly, spanning from 1363.0 K to 537.5 K. Conversely, as the oxygen partial pressure climbs from 21.3 kPa to 96.3 kPa, the critical ignition temperature diminishes from 1719.7 K to 1665.8 K. Under specific conditions of an air flow temperature of 298 K and an air flow rate of 4.1 g/s, the finite volume method calculates a maximum flow velocity of 155.1 m/s near the specimen surface within the combustion chamber. Notably, the computed and experimental values for the critical oxygen partial pressure required for ignition are 93.8 kPa and 88.2 kPa, respectively, exhibiting a relative error of 6.3%.