Scale similarity or gradient models represent attractive, functionally simple expressions for large eddy simulation (LES) subgridscale (SGS) models, showing excellent behaviour in a-priori LES studies for small to moderate filter sizes. However, when applied a-posteriori to real LES calculations, they frequently suffer from numerically unstable behavior. A recent regularization approach revealed promising results for both wall-bounded and free turbulent flows. One attractive feature of this modelling strategy is that it can potentially be applied in many different contexts, such as momentum transport in single or two phase flows, different fluids such as non-Newtonian fluids, etc. The aim of the present study is to test the application of this regularisation technique to turbulent transport of bounded passive scalars. The performance of the model together with suitable discretization strategies will be assessed for turbulent plane free jet simulations. LES results will be benchmarked against DNS calculations of the same configuration obtained with the same code. The new model exhibits good results for momentum and scalar transport, outperforming standard eddy-viscosity models particularly with respect to the prediction of second order moments. Further, they provide good stability and are easy to implement. While the influence of the SGS model for scalar transport is not negligible, it is shown that an appropriate momentum SGS-closure is likely to be more important.

规模相似度或梯度模型代表了大型涡流模拟（LES）子网格规模（SGS）模型的引人注目的，功能简单的表达式，在先验LES研究中（对于中小型过滤器）显示了出色的性能。但是，将后验应用于实际LES计算时，它们经常遭受数值不稳定行为的困扰。最近的一种正则化方法揭示了有边界流和自由湍流的可喜结果。这种建模策略的一个吸引人的特征是它可以潜在地应用于许多不同的环境中，例如单相或两相流中的动量传输，不同的流体（例如非牛顿流体）等。本研究的目的是测试该正则化技术在有界无源标量的湍流输运中的应用。将针对湍流平面自由射流模拟评估模型的性能以及合适的离散化策略。LES结果将以使用相同代码获得的相同配置的DNS计算为基准。新模型在动量和标量传输方面显示出良好的结果，特别是在预测二阶矩方面，表现优于标准涡流-粘度模型。此外，它们提供了良好的稳定性并且易于实现。尽管SGS模型对标量传输的影响不可忽略，但表明适当的动量SGS封闭可能更重要。LES结果将以使用相同代码获得的相同配置的DNS计算为基准。新模型在动量和标量传输方面显示出良好的结果，特别是在预测二阶矩方面，表现优于标准涡流-粘度模型。此外，它们提供了良好的稳定性并且易于实现。尽管SGS模型对标量传输的影响不可忽略，但表明适当的动量SGS封闭可能更重要。LES结果将以使用相同代码获得的相同配置的DNS计算为基准。新模型在动量和标量传输方面显示出良好的结果，特别是在预测二阶矩方面，表现优于标准涡流-粘度模型。此外，它们提供了良好的稳定性并且易于实现。尽管SGS模型对标量传输的影响不可忽略，但表明适当的动量SGS封闭可能更重要。