DOI: 10.2514/1.40966 The dynamics of unstart a floor-mounted inlet/isolator model in Mach 5 flow are investigated experimentally. inlet section contains 6-deg compression ramp, and the isolator is rectangular straight duct that 25.4-mm high by 50.8-mm wide 242.3-mm long. Measurements made include 8-kHz schlieren imaging simultaneous fast-response wall pressures along length inlet/isolator. Unstart initiated deflecting flap at downstream end isolator. shock system, induced unstart, initially...

The interaction of a planar shock wave with dense particle curtain is investigated through modeling and experiments. physics in the between gas-particle mixture markedly differently from that dilute mixture. Following passage wave, expands rapidly as it propagates downstream pressures equilibrate throughout flow field. In simulations, particles are viewed point-particles traced Lagrangian framework. A physics-based model then developed to account for interphase coupling. Compared standard...

The dynamics of unstart in a floor-mounted inlet-isolator model Mach 5 flow are investigated experimentally using particle image velocimetry and fast-response wall pressure measurements. inlet compression is obtained with 6-deg ramp the isolator rectangular straight duct that 25.4 mm high by 50.8 wide 242.3 long. Unstart initiated from scramjet mode (fully supersonic isolator) deflecting motorized flap at downstream end isolator. With fully down, data started capture characteristics boundary...

High-speed disperse multiphase flows are present in numerous environmental and engineering applications with complex interactions between turbulence, shock waves, particles. Compared to its incompressible counterpart, compressible two-phase introduce new scales of motion that challenge simulations experiments. This review focuses on gas-particle spanning subsonic supersonic flow conditions. An overview existing Mach number-dependent drag laws is presented, origins from 18th-century cannon...

An experimental study was conducted to investigate the effects of ramp-type vortex generators in a Wheeler doublet configuration, generator jets, and their combination on supersonic inlet unstart achieve active control unstart. Actuators were placed inner side walls floor-mounted inlet-isolator model Mach 5 flow. Unstart initiated by raising flap at downstream end isolator, which increased back pressure. The passive doublets jets allowed isolator's pressure be raised about 32% higher than...

Time-resolved particle image velocimetry (TR-PIV) has been achieved in a high-speed wind tunnel, providing velocity field movies of compressible turbulence events. The requirements flows demand greater energy at faster pulse rates than possible with the TR-PIV systems developed for low-speed flows. This realized using pulse-burst laser to obtain up 50 kHz, higher speeds cost spatial resolution. constraints imposed by use are limited burst duration 10.2 ms and low duty cycle data acquisition....

Unstart detection techniques based on high-frequency pressure measurements made in a hypersonic inlet―isolator model are investigated. In this study, data that were acquired previous study of backpressure-induced unstart examined. The simplified-geometry consisted 6 deg compression ramp inlet followed by constant-area duct was 25.4 mm high 50.8 wide 227.1 long. Fluctuating wall pressures measured along the length model. A downstream flap used to induce Beyond certain angle, induced, and...

Two-component and stereoscopic particle image velocimetry measurements have been acquired in the streamwise plane for supersonic flow over a rectangular cavity of variable width, peering sidewall lip to view depths cavity. The data reveal turbulent shear layer recirculation region within it. mean position was found be function length-to-width ratio cavity, as turbulence intensity both region. Compressibility effects were observed which levels dropped, thickness decreased Mach number raised...

Experiments were performed to understand the complex fluid-structure interactions that occur during aircraft internal store carriage. A cylindrical was installed in a rectangular cavity having length-to-depth ratio of 3.33 and length-to-width 1. The Mach number ranged from 0.6 2.5 incoming boundary layer turbulent. Fast-response pressure measurements provided aeroacoustic loading cavity, while triaxial accelerometers simultaneous response. Despite occupying only 6% volume, significantly...

A reassessment of historical drag coefficient data for spherical particles accelerated in shock-induced flows has motivated new shock tube experiments particle response to the passage a normal wave. Particle coefficients were measured by tracking trajectories 1-mm spheres flow induced incident shocks at Mach numbers 1.68, 1.93, and 2.04. The necessary accuracy is obtained accounting wall boundary layer growth avoiding interactions between multiple particles. Similar past experiments, current...

The influence of compressibility on the shear layer over a rectangular cavity variable width has been studied in free stream Mach number range 0.6–2.5 using particle image velocimetry data streamwise centre plane. As increases, vertical component turbulence intensity diminishes modestly widest cavity, but two narrower cavities show more substantial drop all three components as well turbulent stress. This contrasts with canonical layers, which significant reductions only and stress due to...

Fluid–structure interactions that occur during aircraft internal store carriage were experimentally explored at Mach 0.58–1.47 using a generic, aerodynamic installed in rectangular cavity having length-to-depth ratio of seven. The vibrated response to the flow its natural structural frequencies, and it exhibited directionally dependent resonance frequencies. Cavity tones excited streamwise wall-normal directions consistently, whereas spanwise was much more limited. Increased surface area...

The flow over an aircraft bay is often represented using a rectangular cavity; however, this simplification neglects many features of actual flight geometry that could affect the unsteady pressure field and resulting loading in bay. To address shortcoming, complex cavity was developed to incorporate more realistic aircraft-bay including shaped inlets, internal structure, doors. A parametric study these conducted based on fluctuating measurements at subsonic supersonic Mach numbers. Resonance...

An experimental study was conducted to investigate the effects of Wheeler Doublets (WDs), Vortex Generator Jets (VGJs), and their combination on supersonic inlet unstart. The final objective investigation achieve active control unstart through use an detection technique most effective these actuators. Actuators were placed in inner side wall a floor-mounted inlet-isolator model Mach 5 flow. Unstart is initiated by increasing back pressure deflecting flap at downstream end isolator. Exclusive...

Pulse-burst PIV measurements at a 37.5 kHz repetition rate are presented, examining the gas-phase velocity up- and downstream of dense particle curtain following interaction with shock wave. From these data, unsteady drag imposed on is estimated using control volume approach.