Experimental Studies in the LENS Supersonic and Hypersonic Tunnels for Hypervelocity Vehicle Performance and Code Validation

“…34 If transition occurs at the extreme low-limit of Reynolds number (6x10 5 ) this would correspond to an altitude of 39.4 km (492.5 sec). A more plausible transition altitude would be that derived from PSE stability analysis, corresponding to a length Reynolds number of 3.7x10 6 .…”

Section: Figure 10 Centerline Transition Reynolds Numbers From Wind Tmentioning

confidence: 99%

“…Although the "unit Reynolds number effect" has been observed and speculated upon for many years, the general consensus is that it seems to be an artifact related to wind tunnel noise. 32 Centerline transition Reynolds numbers are thus expected to lie between 6x10 5 and 1.8x10 6 . With a smooth leading edge surface, transition was observed only under a small number of test conditions corresponding to higher Reynolds numbers within the test matrix.…”

Section: Figure 7 Hifire-5 Reynolds Number and Mach Profilementioning

confidence: 99%

HIFiRE-5 Flight Vehicle Design

Kimmel

Adamczak

Berger

et al. 2010

40th Fluid Dynamics Conference and Exhibit

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The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program executed by the Air Force Research Laboratories (AFRL)and Australian Defence Science and Technology Organization (DSTO). HIFiRE flight 5 is devoted to measuring transition on a three-dimensional body. This paper summarizes payload configuration, trajectory, vehicle stability limits and roughness tolerances. Results show that the proposed configuration is suitable for testing transition on a three-dimensional body. Transition is predicted to occur within the test window, and a design has been developed that will allow the vehicle to be manufactured within prescribed roughness tolerances. I. Nomenclature

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“…The angular extent of these regions increases as the Reynolds number increases, until they merge on the centerline. This merger is not well-defined in time, but seems to occur near Rex = 4x10 6 . Windward transition appears just under Rex=5x10 6 .…”

Section: Table 4 Entry Transition Times Measured With Medtherm Thermomentioning

confidence: 90%

HIFiRE-1 Preliminary Aerothermodynamic Measurements

Kimmel

Adamczak

Paull

et al. 2011

41st AIAA Fluid Dynamics Conference and Exhibit

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The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program executed by the Air Force Research Laboratory (AFRL) andAustralian Defence Science and Technology Organisation (DSTO). HIFiRE flight one flew in March 2010. Principle goals of this flight were to measure hypersonic boundary-layer transition and shock boundary layer interactions in flight. The flight successfully gathered pressure, temperature and heat transfer measurements during ascent and reentry. HIFiRE-1 has provided transition measurements suitable for calibrating N-factor prediction methods for flight, and has produced some insight into the structure of the transition front on a cone at angle of attack. Pressure and heat transfer measurements in the shock-boundary-layer interaction were obtained. Preliminary analysis of the shock boundary layer interaction shows intermittent pressure fluctuations qualitatively similar to those measured in wind tunnel experiments. A large amount of data was obtained on the flight, and significant data reduction efforts continue. Nomenclature Symbolsamplitude at lower neutral bound, dimensionless C h = heat transfer coefficient (Stanton number), , dimensionless C p = specific heat, J/kg K f = frequency, Hz h = altitude, m H = specific enthalpy, J/kg k = thermal conductivity, W/mK L = reference length from stagnation point to flare / cylinder corner, 1.6013 m full scale M = freestream (upstream of vehicle shock) Mach number N = ln[A(f)/A 1 (f)], dimensionless p = pressure, kPa = fluctuating pressure (instantaneous departure from local mean), kPa p = pressure zero-shift at t=60 seconds, kPa = heat transfer rate, W/m 2 Re = freestream unit Reynolds number per meter,  ∞ U ∞ / ∞ s = streamwise surface arc length from stagnation point, m t = time after liftoff, seconds T = temperature, K U = magnitude of the velocity vector, m/s v = velocity component normal to missile x-axis, m/s x = distance from stagnation point along vehicle centerline, m y = vertical (pitch-plane) coordinate, or depth below model wetted surface m 2  = thermal diffusivity, k/C p , m 2 /s  = wind-fixed angular coordinate around vehicle circumference, =0 on windward stagnation line, degrees (Figure 11)  = body-fixed angular coordinate around vehicle circumference,  = 0 on primary instrumentation ray, degrees (Figure 11)  = density, kg/m 3  = viscosity, N s / m 2 Subscripts 0 = stagnation conditions 1 = lower neutral bound m = measured in flight e = evaluated at boundary-layer edge tr = transition location w = evaluated at model wall x = evaluated at distance x from stagnation point ∞ = freestream conditions, upstream of model bow shockAcronyms AFRL Air Force Research Laboratory AoA angle of attack AOSG Aerospace Operational Support Group, Royal Australian Air Force ARC Ames Research Center AVD Air Vehicles Division BC boundary condition BEA best estimated atmosphere BET best estimated trajectory BLT boundary-layer transition

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Experimental Studies in the LENS Supersonic and Hypersonic Tunnels for Hypervelocity Vehicle Performance and Code Validation

Cited by 29 publications

References 11 publications

Progress in shock wave/boundary layer interactions

Progress in shock wave/boundary layer interactions

HIFiRE-5 Flight Vehicle Design

HIFiRE-1 Preliminary Aerothermodynamic Measurements

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