Laser-induced phosphorescence thermometry for dynamic temperature measurement of a film-cooled aero-engine model combustor liner at elevated pressure

Abstract

Accurate knowledge of aero-engine combustor liner temperature fields is essential for cooling design, combustion evaluation, thermal-risk assessment, and life prediction. Although laser-induced phosphorescence (LIP) thermometry enables non-contact, spatially resolved surface thermometry, its application to dynamic two-dimensional thermometry in pressurized liquid-fueled combustors remains limited. In this study, intensity-ratio LIP thermometry was applied to the film-cooled liner of a high-pressure three-sector swirl model combustor under RP-3 aviation kerosene flame impingement. Four coupled operating conditions spanning 1–5 atm were tested. YAG:Dy was used as the thermographic phosphor, with paired dual-frame acquisition for flame-background suppression. Time-resolved liner temperature fields were obtained over approximately 285 s from ignition to a quasi-steady state. At 1 atm, increasing the inlet-air temperature from 500 to 600 K raised the quasi-steady surface-averaged temperature from 873.2 to 1032.4 K. With higher pressure and air mass flow rate but lower fuel-to-air ratio, liner heating accelerated, reaching a maximum rate of 43 K/s in Condition 3, whereas quasi-steady temperatures decreased to 855.5 and 767.2 K in Conditions 3 and 4, respectively. The two-dimensional measurements showed that moderate surface-averaged temperatures could coexist with localized hot spots, while low statistical temperature dispersion did not necessarily imply spatial uniformity. Joint analysis with OH ⁎ chemiluminescence and visible-flame imaging revealed spatial offsets among reaction zones, flame structures, and liner high-temperature regions, indicating that optical flame signals alone cannot quantify liner thermal load. These results demonstrate the feasibility of dynamic two-dimensional LIP thermometry in elevated-pressure model combustors and support the identification of temperature non-uniformities and localized high-temperature risk regions on the liner.