Boundary Layer Stability Analysis for Stetson’s Mach 6 Blunt Cone Experiments

Abstract

The results of a seminal experimental study of the effects of bluntness and swallowing length on transition on an 8-degree cone at zero angle of attack in Mach 6 high Reynolds number flow are analyzed with the STABL computational fluid dynamics code package. Mean flow solutions and PSE-Chem stability analyses for a total of 11 different nose tip bluntnesses, ranging from sharp to 15.24 mm radius, are obtained. For the sharpest cases, N Tr ≈ 7, but as bluntness increases and the calculated swallowing distance lengthens, the computed N-factor at the experimentally-observed transition location drops below the level at which Mack's second mode would be expected to lead to transition. These results indicate that the dominant instability mechanism for the bluntest cases is not the second mode.

Nosetip bluntness effects on transition at hypersonic speeds: experimental and numerical analysis under NATO STO AVT-240

“…This section presents the transient growth analysis of blunt circular cones with conditions selected to match a subset of the configurations from the experiments conducted by Stetson 2 in the Air Force Research Laboratory (AFRL) Mach 6 High Reynolds Number facility and by Marineau 25 in the Arnold Engineering Development Complex (AEDC) Tunnel 9 at Mach 10. Modal instability analysis for the AFRL configurations has been already performed by Jewell & Kimmel, 36 and Marineau 25 has described similar analysis for the AEDC configurations. They found that both first-mode and Mack-mode waves were either damped or weakly unstable for the present configurations; and therefore, transition reversal cannot be predicted with the modal analysis.…”

“…The effect of bluntness on the second-mode instability was first investigated by Malik et al 33 and Herbert & Esfahanian 34 and more recently by Marineau et al 25,35 and Jewell and Kimmel. 36 These recent studies include parabolized stability equation (PSE) analysis of the historical Stetson Mach 6 and Mach 9 blunt cone experiments using the STABL software suite. 37 The stability analyses agree that the transition reversal cannot be predicted by only considering Mack's second-mode instability mechanism.…”

“…The basic states used in the present analysis correspond to the laminar boundary layer flow over the selected blunt cone configurations. The laminar boundary layer flows were computed by Jewell & Kimmel 36 and Marineau 25 with reacting, axisymmetric Navier-Stokes equations on a structured grid. The solver was a version of the NASA data parallel-line relaxation (DPLR) code, 43 that is included as part of the STABL-2D software suite, as described by Johnson 44 and Johnson et al 45 This flow solver employs a second-orderaccurate finite-volume formulation.…”

“…The time integration method is the implicit, first-order data parallel line relaxation (DPLR) method. Additional details about the basic state solution and the grid convergence study are given by Jewell & Kimmel 36 for the AFRL configurations and by Marineau 25 for the AEDC configurations.…”

Analysis of Windward Side Hypersonic Boundary Layer Transition on Blunted Cones at Angle of Attack

“…Good comparisons between computation and experiment were obtained for HIFiRE-1 wind tunnel data using a constant N-Factor of 4 for noisy wind tunnels. Recent work at higher Mach and Reynolds numbers 12,28,29 have indicated that a higher N-factor DISTRIBUTION STATEMENT A: Approved for public release;…”