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。在物理极限内扰动雷诺应力张量的谱表示，是多个商业及开源CFD求解器中获取RANS湍流模型认知不确定性估计的常用方法。近期研究表明，由于求解器稳定性问题的出现，需要调节所考虑的扰动雷诺应力张量的幅度。本文指出，现有的通用实现方法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可能导致调节后的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。因此，计算实现已不再符合特征空间扰动框架的概念本质。我们验证了概念描述在实现过程中的自洽性。充分体现基本概念要求重新构建计算实现，以提升雷诺应力张量扰动的自洽性。