建库温度在超声速火焰面模型中的影响

Effects of Temperature Variation of Flamelet Library on Supersonic Flamelet Modeling

关键词:  超声速燃烧  数值模拟  火焰面模型  火焰面数据库  氧化剂温度

Key words:  Supersonic combustion  Numerical simulation  Flamelet model  Flamelet library  Oxidizer temperature

摘要:

在火焰面模型中，数据库计算结果的准确程度对之后湍流燃烧流场的预测精度有重要影响。为了研究建库温度在超声速火焰面模型中的影响作用，在建立火焰面数据库时增加了建库氧化剂温度这一维度，并提出了一种由流场各点平均温度确定其对应的建库氧化剂温度的查表方法。针对DLR结构的超声速燃烧室，以煤油作为燃料，在五个温度级别条件下建立火焰面数据库，考察了建库温度对一维火焰面数据库以及二维燃烧流场计算结果的影响。研究结果表明，建库温度对一维火焰面的温度和组分分布有较为明显的影响，增加建库温度这一查表维度有助于改善超声速湍流燃烧流场的预测精度。

Abstract:

In the flametlet modeling， the accuracy of flamelet library has a significant impact on the prediction precision of the turbulent combustion flow field. In order to study the effects of temperature variation of flamelet library on supersonic flamelet modeling， the oxidizer temperature was added as a control parameter during the flamelet library generation， and a lookup method to determine the oxidizer temperature from the local temperature for any node in the flow field was proposed. Taken the DLR supersonic combustor as test case and kerosene as fuel， the flamelet library was generated under five different temperature levels， and the effects of temperature on both the one-dimensional flamelet and two-dimensional turbulent reactive flow field were investigated. Results show that the temperature variation has fairly remarkable effects on the temperature and species distributions in one-dimensional flamelet database. Taking the temperature variation into account can help to improve the prediction results of supersonic turbulent reactive flow field.