基于特征时间模型的高效喷雾燃烧数值模拟

开展了基于特征时间（CTS）燃烧模型的高效喷雾燃烧数值模拟研究。基于CTS模型与层流有限速率燃烧模型对CFM56航空发动机模型燃烧室进行了两相数值模拟，通过比较预测的火焰结构验证了CTS燃烧模型在喷雾燃烧中的适用性。通过采用CTS模型初始化燃烧场来提高有限速率燃烧模型的数值模拟效率，提出了基于CTS燃烧模型结合降维方法的高效数值模拟方法。结果表明：CTS燃烧模型较好预测了CFM56模型燃烧室的火焰形态和组分分布，可为有限速率燃烧模型的数值模拟提供良好的初始解；采用自适应建表（ISAT）方法可减小计算时间90%，在此基础上，基于CTS模型初始化的稳态算例收敛时间减少35%，进一步结合降维方法收敛时间减少40%，证明了CTS模型具有提高喷雾燃烧数值模拟效率的潜力。

Efficient spray combustion simulations using the characteristic timescale model

The characteristic time scale (CTS) model was investigated for efficient and robust spray combustion simulations. This model was demonstrated in steady-state simulations of spray flames in an aero-engine model combustor, and the predicted temperature and species results were compared with those from the finite-rate combustion model to verify the feasibility of the CTS model in spray combustion. Combined with a dimension reduction method, the CTS model can be used to facilitate the finite-rate based calculations with full chemical kinetics by providing good initial conditions. The accelerating effect was investigated. Results showed that for the CFM56 model combustor considered, CTS yielded a realistic flame shape and reasonably predicted species distributions. The in situ adaptive tabulation (ISAT) approach reduced the calculation time by 90%. The convergence time of steady-state simulations with initialization based on the CTS model was reduced by 35% and then reduced by 40% if combined with the dimension reduction method. Hence, the proposed characteristic timescale model was valuable in providing good initial conditions for finite-rate based combustion models and in improving the efficiency and robustness of spray combustion simulations.