关键词: 压气机环境, TiAl合金, 可燃性, 表面反应, 临界条件

Abstract: To investigate the flammability of TiAl alloy under compressor conditions, the surface oxidation reaction rate of TiAl was obtained using both an experimental energy balance analysis and a first-principles approach combined with thermodynamic statistics. The effects of incoming flow velocity, temperature, pressure, and angle of attack on the thermal autoignition of TiAl alloy were investigated via numerical simulation. The critical external energy density required for forced ignition under typical multistage compressor design-point conditions was also determined. Results show that although increased pressure promotes surface oxidation, it concurrently enhances convective heat transfer, thereby raising the critical incoming flow temperature for autoignition. At high angles of attack, flow separation significantly reduces heat transfer efficiency, leading to a lower critical autoignition temperature. Under typical simulated conditions of a multi-stage compressor, TiAl alloy does not spontaneously ignite without external energy. However, when the external energy density reaches the thermal levels corresponding to faults such as blade tip friction, there is a risk of forced ignition. This study provides a theoretical basis for assessing the safety of TiAl alloy in compressor environments.

Key words: compressor conditions, TiAl alloy, flammability, surface reactions, critical conditions