Progress in shock wave/boundary layer interactions

Tunable diode laser spectroscopy as a technique for combustion diagnostics

Hypersonic International Flight Research and Experimentation (HIFiRE) Fundamental Sciences and Technology Development Strategy

Ground Test Studies of the HIFiRE-1 Transition Experiment Part 2: Computational Analysis

The Hypersonic International Flight Research and Experimentation (HIFiRE) 5 flight experiment by Air Force Research Laboratories and Australian Defense Science and Technology Organization is designed to provide in-flight boundary-layer transition data for a canonical 3D configuration at hypersonic Mach numbers. This paper outlines the progress, to date, on boundary layer stability analysis for the HIFiRE-5 flight configuration, as well as for selected test conditions from the wind tunnel experiments supporting the flight test. At flow conditions corresponding to the end of the test window, rather large values of linear amplification factor are predicted for both second mode (N>40) and crossflow (N>20) instabilities, strongly supporting the feasibility of first in-flight measurements of natural transition on a fully three-dimensional hypersonic configuration. Additional results highlight the rich mixture of instability mechanisms relevant to a large segment of the flight trajectory, as well as the effects of angle of attack and yaw angle on the predicted transition fronts for ground facility experiments at Mach 6. 1. Background

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Transition Analysis for the HIFiRE-5 Vehicle

*† ‡ § ** The HIFiRE (Hypersonic International Flight Research and Experimentation) project will develop and demonstrate fundamental hypersonic technologies deemed critical to the realization of next generation aerospace weapon systems. Flight one focuses primarily on integration of instrumentation on the test vehicle, with application to future flights. Boundary layer transition has been chosen as one aerodynamic parameter to measure in order to assess instrumentation performance. Analysis has been performed to place requirements on the payload. Results show that the temperature of the aeroshell is relatively benign, easing temperature requirements on transducers. Reynolds number on the vehicle is relatively low, making it marginal for smooth-body boundary layer transition. Roughness must be placed on the vehicle to ensure transition and to obtain rough-wall data. I. Introduction The HIFiRE (Hypersonic International Flight Research and Experimentation) project will develop and demonstrate fundamental hypersonic technologies deemed critical to the realization of next generation aerospace weapon systems. The research effort will consist of a series of focused tasks to resolve hypersonic phenomena through validation of computational analysis; comparison with performance predictions, enhancement of design data bases; and development of correlations with ground test. Each research effort will culminate with a flight experiment to be launched to representative flight conditions (Reynolds number and Mach) employing low cost sounding rockets. The primary objective of flight one is to determine the feasibility of applying high-bandwidth instrumentation to aerothermal flight measurements for short duration hypersonic flights at Mach numbers up to eight. The experiment will determine the suitability and survivability of multiple instrumentation types in this environment. The experiment will be incorporated into the nose cone of a Terrier-Orion launch vehicle. This paper will refer to the nose cone as the “payload.” The measurement of three aerothermal phenomena will serve to assess the performance of the instrumentation. These sub-experiments are, in order of priority, boundary layer transition (BLT), turbulent separated shock boundary layer interaction (SBLI), and optical measurement of mass capture (OMC) in a duct. Measurement of these phenomena will serve as secondary objectives of the experiment. This paper describes analysis related to the BLT experiment to determine requirements for flight one. Boundary layer transition has an important impact on hypersonic vehicle aerodynamics and aerothermodynamics. It is an inherently challenging problem due to its nonlinear nature and sensitivity to initial and boundary conditions. Ground test of boundary layer transition is generally unsatisfactory due to the high noise levels of ground facilities compared to flight. Computation is challenging since it requires resolution of instabilities of relatively high wavenumber and frequency over large spatial domains. Flight provides the best environment for measuring transition. Instrumentation for the flight environment however, is challenging. The highest level of validation for transition prediction requires high bandwidth instrumentation. The current tests will explore the use of high-bandwidth instrumentation for flight measurement of transition. Careful measurement and computation of boundary conditions will provide added value in interpreting the data. Data from numerous past flight tests of supersonic and hypersonic transition exist. Schneider 1 offers a detailed review of transition flight tests. Vehicles were frequently thin-skin models. Backface thermocouples monitored transition, and heat transfer rates were inferred by lumped-capacitance heating models. Transition criteria based on

HIFiRE-1 Boundary Layer Transition Experiment Design

The Hypersonic International Flight Research Experimentation (HIFiRE-5) is a hypersonic flight test vehicle designed to investigate the aerothermodynamics of a three-dimensional geometry. It is a 7-deg minor-axis half-angle elliptic cone with a 2∶1 aspect ratio and 2.5 mm nose radius. The flight test occurred in April 2012, but the upper stage of the sounding rocket failed to ignite, resulting in a peak Mach number of about 3 instead of the target of 7. The instrumentation (almost 300 thermocouples and 50 pressure transducers) performed well and provided a wealth of supersonic aeroheating and boundary-layer transition data. The pressure transducers indicated the expected dependence upon angle of attack and yaw and offer a check for the inertial measurement unit. Heat flux was calculated from paired thermocouples and boundary-layer transition locations were identified from the heating rates. Two boundary-layer transition mechanisms were encountered during the supersonic descent. One mode leads to transitio...

HIFiRE-5 Flight Test Results

HIFiRE (Hypersonic International Flight Research Experimentation) is a joint flight test program supported by the US Air Force Research Laboratory (AFRL) and the Australian Defence Science and Technology Organisation (DSTO). One of the main program goals is to gather basic research data on aspects of hypers onic flight not easily accessible to ground testing. Flight one focuses primarily on integration of instrumentation on the test vehicle, with application to boundary layer transition and shock interaction experiments. The HIFiRE 1 payload consists of a blunted 7° half angle cone and a cylinder/33° flare configuration. The payload will be boosted to Mach 8 utilizing a two stage Terrier-Orion sounding rocket. The payload was designed and manufactured to achieve the desired boundary layer transition and shock boundary layer interaction properties and collect the required data. Extensive analysis and ground testing was conducted to ensure the payload will survive the expected flight environment. The HIFiRE 1 launch campaign is scheduled for March 2010. A number of valuable lessons learned during the development of HIFiRE 1 are included in this paper. I. Introduction HIFiRE is a cooperative flight test program between the United States and Australia. The goal of this program is to advance technologies associated with hypersonic flight. Special emphas is is placed on exploring phenomena not readily accessible to ground tests. Fli ght one will focus on instrumentation an d telemetry systems to be used for flights occurring later in the program. The primary objec tive of HIFiRE 1 is to determine the feasibility of applying high-bandwidth instrumentation to aero-thermal flight measurements for short duration hypersonic flights at Mach numbers up to eight. The experiment will determine the suitability and survivability of multiple instrumentation types in this environment. The experiments will be incorporated into the nose cone of a Terrier-Orion launch vehicle 1 . This paper will refer to the nose cone as the “payload.” The measurement of three aero-thermal phenomena will serve to assess the performance of the instrumentation. The corresponding sub-experiments are, in order of priori ty, boundary layer transition (BLT), turbulent separated shock boundary layer interaction (SBLI), and optical measurement of mass capture (OMC). This paper describes the design, manufacture, integration and ground testing of the payload. It also includes valuable lessons that were learned during this process. The scientific motivations for the primary and secondary experiments on HIFiRE 1 have been discussed in a number of published papers 2,3,4,5,6,7,8,9 and will not be repeated here. Design parameters critical to the BLT experiment have been derived from past correlations, computational analyses and ground testing. The most critical paramete rs affecting the BLT experiment are surface roughness and step/gap sizes at and between payload sections. The most restrictive values were 0.08mm for an allowable discrete roughness and 0.001mm root mean square (rms) roughness at the nosetip (relaxing to 0.008mm rms aft of the nosetip). More recent results 3,10 indicated that larger values would have been acceptable, however the more restrictive roughness limits were employed for the payload design to provide a generous factor of safety for the experiment. A discrete roughness trip was installed on one side of the payload with the aim of extracting

HIFiRE-1: Payload Design, Manufacture, Ground Test, and Lessons Learned

The Hypersonic International Flight Research Experimentation program is a hypersonic flight test program. It successfully measured the three-dimensional transition front on a cone at angle of attack in hypersonic flight during its reentry. The test article consisted of a nonablating, 7 deg half-angle, axisymmetric cone with a small bluntness of 2.5 mm radius. During transition, angle of attack dropped from 13 to 5 deg and freestream unit Reynolds number increased from 2×106 to 8×106/m. Mach number during this time was approximately seven. Earliest transition, determined from fluctuating pressures, occurred on the leeward meridian, at Rex=3.1×106, α=13  deg, and M=7. Attachment line transition occurred at Rex=4.7×106, α=9  deg, and M=7. The latest transition occurred off the windward meridian at Rex=6.0×106 and Φ=30 and 280 deg. Transition occurred at lower Reynolds numbers than the α=0  deg transition measured during ascent (Rex=11×106 at M=5.2). The azimuthally averaged transition Reynolds number determi...

Boundary-Layer Transition Experiment During Reentry of HIFiRE-1

The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program. The primary experiment for flight one, launched in March 2010, was to measure boundary-layer transition in hypersonic flight on a nonablating, 7 deg half-angle axisymmetric cone with a small bluntness of 2.5 mm radius. The flight gathered pressure, temperature, and heat transfer measurements during ascent and reentry. Although the vehicle reentered the atmosphere at a higher-than-intended angle of attack, the ascent portion of the flight provided smooth-body boundary-layer transition data at freestream Mach numbers greater than 5, where transition was presumed to be dominated by second-mode instability. The angle of attack during this portion of the flight was less than 1 deg. The end of turbulent-to-laminar transition occurred at Reynolds numbers between 10.3×106 and 12.2×106, based on x-location and freestream conditions. Transition was correlated with second-mode N-factors of approximately...

David Adamczak

Papers

HIFiRE-1 Boundary Layer Transition Experiment Design

HIFiRE-5 Flight Test Results

HIFiRE-1: Payload Design, Manufacture, Ground Test, and Lessons Learned

Boundary-Layer Transition Experiment During Reentry of HIFiRE-1

HIFiRE-1 Ascent-Phase Boundary-Layer Transition