The limitations of turbulence closure models in the context of Reynolds-averaged NavierStokes (RANS) simulations play a significant part in contributing to the uncertainty of Computational Fluid Dynamics (CFD). Perturbing the spectral representation of the Reynolds stress tensor within physical limits is common practice in several commercial and open-source CFD solvers, in order to obtain estimates for the epistemic uncertainties of RANS turbulence models. Recent research revealed, that there is a need for moderating the amount of perturbed Reynolds stress tensor tensor to be considered due to upcoming stability issues of the solver. In this paper we point out that the consequent common implementation can lead to unintended states of the resulting perturbed Reynolds stress tensor. The combination of eigenvector perturbation and moderation factor may actually result in moderated eigenvalues, which are not linearly dependent on the originally unperturbed and fully perturbed eigenvalues anymore. Hence, the computational implementation is no longer in accordance with the conceptual idea of the Eigenspace Perturbation Framework. We verify the implementation of the conceptual description with respect to its self-consistency. Adequately representing the basic concept results in formulating a computational implementation to improve self-consistency of the Reynolds stress tensor perturbation

翻译：湍流封闭模型在雷诺平均纳维-斯托克斯（RANS）模拟中的局限性是导致计算流体动力学（CFD）不确定性的重要因素之一。在物理限值内扰动雷诺应力张量的谱表示，已成为多个商业及开源CFD求解器估算RANS湍流模型认知不确定性的常规做法。近期研究表明，由于求解器可能出现的稳定性问题，需对扰动雷诺应力张量的幅度进行适当调节。本文指出，这种普遍采用的实现方式可能导致最终扰动雷诺应力张量出现非预期状态。特征向量扰动与调节因子的组合实际上会产生已调节特征值，这些特征值不再与原始未扰动和完全扰动特征值保持线性依赖关系，从而导致计算实现与特征空间扰动框架的概念设想相悖。我们从自洽性角度验证了概念描述的实现方式。通过恰当表达基本概念，提出了改进雷诺应力张量扰动自洽性的计算实现方案。