RANS predictions for high-speed flows using enveloping models

Quantification of Reynolds-averaged-Navier-Stokes model form uncertainty in transitional boundary layer and airfoil flows

“…In Fig. 8, an "enveloping behavior" with respect to the baseline prediction is observed, and this behavior has been observed by other researchers as well, e.g., see 9,[11][12][13] . In Fig.…”

“…On the other hand, the k − ε model's response to ∆ B is larger than that for SST k −ω, and again appears to be linear with ∆ B ; however, it is clear that the k − ε model overall gives much larger predicted value of C f than the experimental data; consequently, no experimental data are encompassed by the uncertainty bound generated from the k − ε model. It should be noted that thus far most UQ studies have focused on turbulent flow simulations, from which the 1c and 2c perturbations always increase the value of C f , while the opposite is true for the 3c perturbation, e.g., see 12,47,53 , which is consistent with the behavior observed with the SST k −ω and k −ε turbulence models, as well as the behavior observed in the fully turbulent region with the SST k − ω LM transition model. Figure 9 shows decaying of Tu in freestream as a function of Re x .…”

“…This framework quantifies the model form uncertainty associated with the linear eddy viscosity model via sequential perturbations in the predicted amplitude (turbulence kinetic energy), shape (eigenvalues), and orientation (eigenvectors) of the anisotropy tensor. This perturbation method for RANS model uncertainty quantification has been applied to analyze and estimate the RANS uncertainty in flow through scramjets 10 , aircraft nozzle jets, turbomachinery, over stream-lined bodies 11 , supersonic axisymmetric submerged jet 12 , and canonical cases of turbulent flows over a backward-facing step 13,14 . This method has been used for robust design of Organic Rankine Cycle (ORC) turbine cascades 15 .…”

Probabilistic Analysis of Aircraft Using Multi-Fidelity Aerodynamics Databases

“…The eigenspace perturbation methodology has exhibited substantial success in various engineering applications. This methodology has been successfully applied to the analysis of uncertainty in flows through scramjets [34], contoured aircraft nozzles [2,81,83,85], and turbomachinery designs [32]. The methodology has been used for the design optimization under uncertainty of turbine cascades [106] and in aerospace designs [22].…”

Multi-Fidelity modeling of Probabilistic Aerodynamic Databases for Use in Aerospace Engineering

“…The eigenspace perturbation methodology has exhibited substantial success in a variety of engineering applications. This methodology has been successfully applied to the analysis of uncertainty in flows through scramjets [25], contoured aircraft nozzles [26,27], and turbomachinery designs [28]. The methodology has been used for the design optimization under uncertainty of turbine cascades [29].…”