基于真实气体效应的湍流标度律特性

Characteristics of Turbulent Scaling Law in Real Gas Effects

在量热完全气体、热完全气体和化学反应完全气体等3种气体模型假设下,利用Mach数为4.05、壁温为1 300 K的超声速槽道湍流的直接数值模拟(direct numerical simulation,DNS)结果,对标度律和自相似性做了详细分析.结果表明,不仅在量热完全气体模型下存在标度律和扩展自相似性,而且在热完全气体和化学反应完全气体模型下标度律和扩展自相似性仍然成立.压缩性的影响使得速度结构函数通过Favre平均获得更为合适.与热完全气体模型的结果相比,化学反应完全气体和量热完全气体模型的结果吻合更好.

In order to analyze the scaling law and extended self-similarity in detail, temporally evolving supersonic- turbulent channel flows （reference Mach number at 4.05 and wall temperature at 1 300 K based on the wall parameters） were simulated using direct numerical simulation （DNS） approach. The gas models include calorically perfect gas, thermal-ly perfect gas and chemically reacting gas in non-equilibrium （chemically reacting gasr for short）. The two later kinds of models are called by a joint name as the real gas models. It is found that the scaling law and extended self-similarity not on-ly exist in calorically perfect gas, but also in real gas models. The Favre parameters are suitable to obtain velocity structure function because of the compressibility influence. The deviations between chemically reacting gas and calorically perfect gas provide better agreement than that between thermally perfect gas and calorically perfect gas.