Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"Shadowgraphy"”.
-
Laser, optical and electrical diagnostics of colliding laser-produced plasmas
… gas interface which rapidly expands outwards. Shadowgraphy is currently the most widely employed diagnostic technique to analyse such shock fronts and a comparison of both techniques reveals that interferometry can be used to diagnose the interaction of laser produced plasmas in gaseous …
-
CHARACTERIZATION OF THE INITIAL SPRAY FROM A JET IN CROSSFLOW
… liquid jet in air crossflow was conducted using Shadowgraphy and Particle Image Velocimetry (PIV) techniques. Momentum ratio and gas Weber number were varied to study their effects on the column trajectory, spray trajectory, breakup locations and spray characteristics after column breakup. …
-
Measurements of Magnetic Compression and Melt of Electrically Thick Metals Driven by Lineal Current Densities Characteristic of Pulsed-Power-Driven Fusion Devices
… such as high-speed imaging, PDV, and laser shadowgraphy, tracked the surface motion and instability growth on mm-diameter aluminum rods driven to megampere currents in less than 200 ns. The experimental measurements are being used to benchmark magnetohydrodynamic calculations and thereby …
-
Multi-Physics Model of a Dielectric Barrier Discharge Flow Control Actuator with Experimental Support
… validated against the time-resolved shadowgraphy. The model demonstrates the capability to replicate emergent flow structures near a wall. These structures contribute to momentum transport that enhance the boundary layer’s wall attachment and provide for better flow control. An …
-
Visualising convective heat transfer in a propagating wildland fire
… diagnostic techniques, including Retroreflective Shadowgraphy (RS) and Background Oriented Schlieren (BOS), to visualise and quantify heat transfer dynamics. Thermocouples, Pitot tubes, and heat flux sensors were used to capture physical measurements for validation. The results reveal that …
-
Fuel Droplet Optical Diagnostic Techniques for Lean Premixed Prevaporized Aeroengine Combustors
… are also evaluated. Finally, narrow linewidth shadowgraphy is employed to measure liquid fuel droplet sizes in the flame at high temperature and high pressure conditions. Overall, the optical diagnostics developed and tested in this work enable more detailed studies of fuel droplet and flame …
-
Laser-induced forward transfer techniques for printing functional materials and photonic devices
… for energy harvesting applications. A nanosecond shadowgraphy technique was used to study the triazene polymer (TP)-dynamic release layer (DRL) assisted LIFT technique for solid-phase ceramic materials namely gadolinium gallium oxide (Gd-Ga-O) and ytterbium doped yttrium aluminium oxide (Yb:YAG). …
-
Microwave Triggered Laser Ionization of Air
… microphone, microwave detector, and others. Shadowgraphy with a nanosecond time resolution will be used to detect changes in the shockwave fronts when the HPM signal overlaps the laser pulse in time and space. Detailed experimental setup and experimental results are presented. A complete …
-
Effect of Flow Distortion on Fuel Mixing and Combustion in an Upstream-Fueled Cavity Flameholder for a Supersonic Combustor
… fuel injection momentum ratio is also examined. Shadowgraphy is used to characterize the flowfield while planar laser induced fluorescence of the NO and OH molecules are used to measure the fuel mixing and combustion, respectively. These experimental data are compared with CFD solutions of the …
-
High-Resolution Experimental Measurements and Mechanistic Modelling of Saturated Cryogenic Pool Boiling Heat Transfer
… bubble using both phase-detection and shadowgraphy showed the lack of microlayer. Instead, the large size of the bubble footprint observed experimentally strongly suggested an intense evaporation process at the triple contact line of the bubbles and occurring right after nucleation. …
-
Theoretical and Experimental Studies of Radiation from High-Z Multiply Ionized L-shell Ions with Emphasis on X-ray Line Polarization
… cameras, fast x-ray diodes, and an optical laser shadowgraphy system. Three primary objectives are addressed using these theoretical and experimental tools. First, a study of the line emission and x-ray line polarization of multiply ionized Molybdenum (Mo) ions is accomplished. …
-
Shock Waves in Gas and Plasma in Strong Magnetic Fields
… This includes 266 nm interferometry, 532 nm shadowgraphy, schlieren imaging, 4-frame side-on imaging perpendicular to the rod, and vertical imaging parallel to the rod axis. These diagnostics enable time-resolved measurement of shock front position, curvature, density gradients, and velocity …
-
Shock oscillation mechanisms of highly separated transitional shock-wave/boundary-layer interactions
… as high-speed Schlieren imaging, spark light shadowgraphy, and particle image velocimetry (PIV), the research identifies a specific mechanism driven by the interplay of natural laminar separation growth, transition through shear layer instabilities, and separation suppression through …
-
Flow visualisation and fundamental aspects of two-dimensional turbulent plumes
… in this research to observe these plumes is shadowgraphy. Perhaps surprisingly, much of the underpinning theory of this method has, to date, been restricted to the case where the flow field of interest is illuminated by collimated light (i.e. illuminating light rays are parallel to each …
-
Structure and stabilization of cryogenic spray flames
The success of a satellite launcher depends to a great extent on its efficiency and reliability. Engines using cryogenic fuels, such as liquid oxygen and hydrogen, are used for most missions since they combine high performance with a relatively light structure. The design of such motors has, until …