Observation of Cross-Flow Instability Mode over a Yawed Cylinder at Mach 2

Abstract

Nomenclature Q ∞ = velocity in the freestream direction U ∞ = velocity in the chordwise direction perpendicular to the leading edge V ∞ = velocity in the spanwise direction parallel to the leading edge x = distance in the local external flow direction y = distance in the normal-to-wall direction z = distance in the direction perpendicular to both x and y α = real part of complex wave number in x direction β = real part of complex wave number in z direction λ = wavelength in the wave-number vector direction λ S = wavelength in the spanwise direction ν = kinematic viscosity ϕ = angle measured from the leading edge in the chordwise direction, deg χ = wave-number vector angle measured from local external streamline ψ = angle of external streamline deviation from the chordwise direction

Humidity Effects on Unsteady Characteristics of Supersonic Flow

“…14) under the present experimental condition predicts this wavelength to be 0.82 [mm]. Good agreement between experiment and analysis suggests that the striations may be attributable to the action of a row of stationary vortices originating from a cross-flow instability.…”

“…This time-dependent modes peaking at approximately 60kHz and growing downstream as shown in Fig.10a may be identified with the cross-flow instability mode 14) . …”