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 20 of 28 for “"vortex system"”.
-
Time-resolved heat flux measurements of the turbulent junction vortex system
… unsteady heat flux in a complex junction vortex flow. This sensor, called the Heat Flux Microsensor, was used with a hot-wire anemometer to make simultaneous measurements of velocity and surface heat flux. The results were used to detect the relationship between the surface heat flux and …
-
Plasmoid Vortex System Retrofit a Sustainability and Efficiency Study on Internal Combustion Engines
<p>The thesis addresses the persistent inefficiency and environmental degradation caused by internal combustion engines in modern vehicles, a major issue as the automotive industry faces increasing pressure to reduce fuel consumption and greenhouse gas emissions. Internal combustion engines, which …
-
Determination of Bragg Scatter in an Aircraft Generated Wake Vortex System for Radar Detection
… temperature fields being mixed by the wake vortex system. Refractive index variations of the size that correspond to half the operating radar wavelength produce the observed radar return. Previous analysis has postulated turbulence within the wake vortex to be the generator of the index of …
-
Effective methods of controlling a junction vortex system in an incompressible, three-dimensional, turbulent flow
… find effective methods of controlling a junction vortex system around and in the wake of a NACA 0020 body with a 1.5:1 elliptical nose mounted normal to the flat surface. Control of the junction vortex system was investigated using more slender noses and leading edge fillets. The study includes …
-
All The King's Horses: The Delta Wing Leading-Edge Vortex System Undergoing Vortex Breakdown: A Contribution to its characterization and Control under Dynamic Conditions
… the wing. The three-dimensional streamline and vortex line distributions were visualized. Isosurfaces of vorticity, planar distributions of helicity and all three vorticity components, and the indicator of the stability of the core were studied and compared to see which indicated breakdown …
-
Untersuchungen zur Entstehung und Stärke von Triebwerkseinlaufwirbeln
A vortex system can occur in an inlet of a jet engine operated near the ground. These vortices reach into the inlet and can show significantly different strength and shape dependent on several geometrical and flow parameters. The inlet-vortices often form especially with a foot on the ground when …
-
Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets
… than the water depth. After the starting jet vortex dipole detaches from the inlet, secondary vortices shed due to separation from the inlet boundary and eventually reach the starting-jet dipole. An idealized inlet con figuration was utilized for laboratory experiments detailing the formation …
-
Untersuchung von 4-Wirbelsystemen zur Minimierung von Wirbelschleppen und ihre Realisierung an Transportflugzeugen
… approach for assessing the potential of 4-vortex wakes concerning an alleviation of the wake vortex hazard is presented. The first step of the numerical approach comprises the systematic investigation of 4-vortex topologies representing generic farfield vortex wakes. Once a configuration …
-
Numerical Investigations of Magnetohydrodynamic Hypersonic Flows
… code toward the solution of the Orszag-Tang vortex system.
-
A Numerical Study of the Flow and Heat Transfer in the Near Field of a Cylindrical Bubble Moving in a Narrow Channel
… bubble diameters. A complex horseshoe-like vortex system wraps the bubble and drives the heat flux lobes. The evolution of the heat flux at a point on the surface compares well to predictions of an existing quenching/diffusion model.
-
Influence of aspect ratio on dynamic stall of a finite wing
… to variations in the influence of the trailing vortex system on the dynamic stall behavior of the finite wings. Moreover, the computational results revealed that, for wings pitching at low angles of attack, a decrease in aspect ratio corresponds to a decrease in phase lag of the unsteady …
-
Aerodynamics of a chined forebody oscillating in pitch
… visualization were utilized to determine the vortex system and help interpret the surface pressure data.
-
Particle filtering with Lagrangian data in a point vortex model
… filters for LaDA using a two-dimensional point vortex model; this is a simplified fluid dynamics model wherein the positions of vortex singularities (point vortices) define the state. We consider various parameters associated with algorithm and examine their effect on filtering performance under …
-
Distribution of aerofoil section lift from section pitching moment applied to a dynamic model for aircraft poststall departure
… wake effects due to a discrete, nonplanar vortex system. The fidelity and vortex distribution of the wake is made adjustable under the constraint that the vortex distribution on the surface of the wing provide the same two dimensional angle of attack as did a single bound lifting line. The …
-
Strömungs- und Wärmeübergangsmessung für das zweistufige Raumtransportsystem ELAC
… horizontally starting space transportation systems are going to replace vertically starting systems to bring men and material safely into space. These space shuttles act as lifting bodies, i.e. they take off and land like conventional airplanes. The two-stage space transportation system …
-
Heat Transfer and Flow Characteristics on the Rotor Tip and Endwall Platform Regions in a Transonic Turbine Cascade
… squealer cavity vortices and endwall auxiliary vortex system, which significantly increase the stage aerodynamic losses. Furthermore, these vortices result in a low film-cooling effectiveness as was observed on a squealer tip cavity with purge flow. Finally, the importance of transonic …
-
Two-degree-of-freedom subsonic wing rock and nonlinear aerodynamic interference
… in conjunction with the general unsteady vortex-lattice method to compute simultaneously the motion of the wing and the flowfield, fully accounting for the dynamic/aerodynamic interaction. For a single degree of freedom in roll, the method predicts the angle of attack at which the …
-
Observation and measurements of flow structures in the stagnation region of a wing-body junction
The behavior of a junction vortex formed around an obstacle in a boundary layer flow was studied experimentally in a water tunnel for two low speed cases. A wing consisting of a 3 : 2 elliptical nose and an NACA 0020 tail was used to simulate the junction vortex. A visual study using a hydrogen …
-
Computational modelling of the vortex state in high-temperature superconductors
The vortex state in high temperature superconductors is investigated using computer simulations. Vortices are represented as particles and we employ Langevin dynamics to study the statics and dynamics of the system.<br/><br/>We show that the long-range nature of the vortex-vortex interaction can …
-
A dynamic model for aircraft poststall departure
… wake effects due to a discrete, nonplanar vortex system. A fully configured aircraft (main wing, horizontal tail and vertical fin) is mathematically constructed by modeling all lifting surfaces with bound, discrete vortex segments and associated control points; vehicle geometric influence …
Page 1 of 2