Shock-wave/boundary-layer interactions in laminar and fully turbulent boundary layers have been widely investigated previous efforts, but relatively little research has conducted to explore the between a shock wave transitional layer. Here, cylinder-induced shock-wave/transitional boundary-layer interaction is using high-speed Schlieren imaging collected at 100 kHz. The occurred on flat plate model Mach 1.78 flow upstream of 3.2-mm-diam cylinder model, which was positioned 15 unique...

Focused laser differential interferometry (FLDI) is used to measure a well-characterized, 17 kHz screech tone emitted from an underexpanded Mach 1.5 jet. Measurements are made at numerous spatial locations in and around the jet flow-field, where intrusive diagnostics would otherwise influence flow-field. Results FLDI measurements shown agree with microphones analyses of high-speed schlieren. The agreement demonstrate valid accurate technique for measuring tones flow-fields, furthermore that...

Shock-wave/boundary-layer interactions (SWBLIs) are critical phenomena in the design of high-speed vehicles as they exhibit inherent unsteadiness that can damage airframes and lead to engine unstart. This paper presents a novel characterization unsteady dynamics cylinder-induced SWBLIs at Reynolds numbers using proper orthogonal decomposition (POD) dynamic mode (DMD). Data sets analyzed this were obtained from experiments conducted NASA Langley Research Center's 20-Inch Mach 6 blowdown wind...

View Video Presentation: https://doi.org/10.2514/6.2023-1457.vid A new hypersonic Ludwieg tube has been constructed at the University of Tennessee Space Institute (UTSI) to support increased research activities related vehicle development. The 45.72 cm by (18" 18") nozzle exit dimension allows for large models be tested and development flow diagnostic techniques on a scale similar high-speed test evaluation (T&E) facilities AEDC. description facility design initial characterization is...

View Video Presentation: https://doi.org/10.2514/6.2022-1660.vid A fast-response temperature sensitive paint has been selected for use in the University of Tennessee Space Institute's Ludwieg Tubes. The is based on a ruthenium complex called ru(phen) which produces fluorescence under ultraviolet excitation that correlates to temperature, with response time suitable hypersonic test facilities sub-second steady state run times. This work presents benchtop characterization and initial tests...

View Video Presentation: https://doi.org/10.2514/6.2023-2445.vid The surface aerothermodynamic effects of shockwave-boundary layer interaction over a 6-degree half-angle cone with shock-generating protruding cylinder under Mach 7 flow were measured by means temperature-sensitive paint on the model and compared to schlieren imaging features. global heat across quantified spatially correlated visualization shock-boundary near shock generator. A slight increase in temperature was observed begin...

A novel actuator concept is evaluated in a series of active flow control experiments on resonant high-speed cavity flow. The generates pulsed supersonic microjets by using the resonance an impinging microjet source, and with smart materials incorporated into its design, actuator's frequency can be actively controlled. was designed such that would lie within range predicted resonance. Results from Mach 1.5 over length are presented, performance across three modes operation: pulsed, steady. In...

Two-component particle image velocimetry was employed to measure the influence of surface roughness on a Mach 2 boundary layer. Three conditions were examined: smooth wall, patterned diamond-shaped roughness, and an approximately random realistic roughness. The response layer characterized in ensemble-averaged measurements mean velocity Reynolds stresses. streamwise development mechanical distortions introduced by also explored through observation roughness-generated shock waves changes...

View Video Presentation: https://doi.org/10.2514/6.2021-0384.vid The University of Tennessee Space Institute has constructed a Mach 4 Ludwieg Tube (M4LT) in the Aerothermodynamics Laboratory (TALon). UTSI TALon M4LT two-dimensional, planar nozzle connected to 24" x 72" test section that allows for use models bridge gap between scales used foundational research those Test and Evaluation (T&E) community. facility is designed with substantial optical access variety diagnostic techniques such as...

Two-component particle image velocimetry was employed to measure the effects of mechanical distortions caused from surface roughness topologies on a Mach 2 boundary layer. The first goal this study characterize responses supersonic layer various topologies. These were characterized in ensemble averaged mean velocity characteristics as well turbulent intensity through Reynolds Stresses. second streamwise development over diamond topology. Measurements taken at three measurement locations...

An experimental study concerning an underexpanded, screeching, Mach 1.5 jet operating at a stagnation-to-ambient pressure ratio of 4.4 is presented. Experimental data were acquired from high-speed schlieren imaging (100,000 frames per second) as well pulse-burst particle image velocimetry (PIV) 50 kHz. Spectral analyses these are presented and compared, the results modal using both proper orthogonal decomposition (POD) spectral POD (SPOD). Comparisons revealed that images PIV vector fields...

This work demonstrates the capability of a high speed camera as detector for focused laser differential interferometry (FLDI) cylindrical lens setup. To test system’s capability, tube jet was bisected at various x/d locations by signal. The normalized fluctuation profiles each these were compared to from schlieren same jet, with both systems showing close agreement in width and profile locations. Measurements thin, flat plate boundary layer height, ��99 ∼ O(2����), made, highlighting...

A fluidically driven microactuator that generates supersonic, pulsed microjets has been implemented with smart materials to actively and precisely control the frequency of in a closed-loop manner. Since this actuator relies on number microscale flow acoustic phenomena produce microjets, its resonant is determined by geometry other parameters. The design discussed paper integrates piezoelectric stacks connecting them movable sidewalls within such microactuatorʼs internal can be controlled...

This work expands on previous efforts that observed high-intensity resonance in the dynamic shock motion generated by wave/boundary layer interactions with Mach 1.8 edge conditions when inflow boundary is transition. Specifically, this effort characterizes behavior of a thickening upstream separation location appears to strongly correlate influence shock; also verifies focused spectra measurements cylinder flat plate are blunt fin or cone similar conditions. The waves transitional...

Research in actuator development over the past few years has been driven towards increasing their amplitude and bandwidth thus enabling users to refine adapt actuators for a wide array of applications. Recent developments at Advanced Aero Propulsion Laboratory (AAPL) Florida State University (FSU) have produced micro-actuator that is capable producing pulsed, supersonic microjets by utilizing number micro-scale, flow-acoustic resonance phenomena – this referred as Resonance-Enhanced Microjet...