Instability Modes in Boundary Layers of an Inclined Cone at Mach 6

Abstract

The stability of a three-dimensional hypersonic boundary layer is experimentally investigated for a 7° half angle cone at an angle of attack of 6°. The measurements were carried out in the Hypersonic Ludwieg tube Braunschweig at a Mach number of 6. Surface mounted pressure sensors were used to capture information about the spatial extension, frequency content and wave structure of first and second mode instabilities. Infrared images were used to identify the location, direction and growth of stationary cross flow instabilities. In the present work the behavior of these disturbances at noisy wind tunnel conditions is described for different locations along the cone and Reynolds numbers. Nomenclature 2D= Two dimensional 3D = Three dimensional DFT = Discrete Fourier transform HLB = Hypersonic Ludwig tube Braunschweig IR = Infrared PSD = Power spectral density Symbols dt = time step n = distance along the surface of the cone perpendicular to s s = distance along the surface of the cone parallel to the local streamlines x = distance along the principal axis of the cone z = distance along the surface of the cone perpendicular to the principal axis of the cone θ = azimuthal angle around the model main axis

Secondary Instabilities of Hypersonic Stationary Crossflow Waves

“…One way to do this may be to use large amplitude roughness, which will increase the initial amplitude of the stationary vortices. Secondary instabilities of the stationary crossflow waves may have already been measured in Mach 6 noisy flow by Muñoz et al [41,49], but further research is necessary.…”

“…The unique feature of the Modular Cone is the ability of the sensor frustum to rotate independently of the rest of the cone. This feature and the cone design were inspired by Muñoz et al [41].…”

Developing Mechanism-Based Methods for Estimating Hypersonic Boundary-Layer Transition in Flight: The Role of Quiet Tunnels

“…angle of attack is being used by several researchers as another canonical configuration for experimental and computational study at Mach 6 (e.g., Refs. [96,97,98,99,100,101]). Although much can be inferred from the extensive literature on swept wings at low speeds, it is not yet clear how much will be different.…”

Experimental investigation of a newly designed supersonic wind tunnel

“…The data acquisition card is the Spectrum M2i.4652 transient recorder, and the sampling frequency was set to 2.5 MHz in the sharp cone measurement. Figure 6 Cone model used in the experiments [7]. Dimensions are in millimeters…”

“…Dynamic measurements in the wind tunnel were accomplished by PCBM132A31 sensors installed on a 7 degree half-angle sharp cone model [7]. The PCB sensors are §ush mounted to measure the surface pressure §uctuation.…”