Engineering Commons^™

Experimental Modelling Of Downburst And Downburst Line Outflows, Kyle Graat

Electronic Thesis and Dissertation Repository

The outflow velocity vector fields of simulated stationary thunderstorm downbursts and downburst lines were resolved in two plane orientations, vertical and horizontal, using a dense fluid release system and Particle Image Velocimetry. Single event releases were scaled to show agreement with past studies based on radial velocity magnitude and location and radial and vertical front propagation. The vortex trajectory of a single event using the vortex aspect ratio supported density's role in the outflow after the time and location of the maximum radial velocity. The interaction between two release events varied temporally and spatially and showed that the interaction region's …

Experimental Investigation Of The Heat Source Orientation On The Transient Flow And Thermal Behaviour Of Phase Change Material During Phase Transition, Steven Jevnikar

Electronic Thesis and Dissertation Repository

The present study reports the characterization of transient flow and transient thermal behavior of phase change material (PCM) during solid-liquid phase change (melting) through experimental investigation. Two specific aspects of the current work, both important in the field of latent heat thermal energy storage, are to investigate the influence of the flow behavior within liquid PCM on the melting and heat transfer processes, and the impact of heat source orientation on the underlying melting and heat transfer processes. A relationship between heat source orientation and the Nusselt number was discussed. The results show that the fluid velocity is critical for …

The Spanwise Structure Of The Roof-Level Turbulence In A Street Canyon Flow, Tomek Jaroslawski

Electronic Thesis and Dissertation Repository

In the present work, for the first time, the spanwise organization of turbulent flow along an urban street canyon subjected to wind normal to the street axis using a boundary layer wind tunnel is systematically investigated.The effect of upstream roughness and canyon width on the turbulence in a street canyon flow is presented. Measurements in a horizontal plane were conducted at near roof-level of a street canyon using Stereoscopic Particle Image Velocimetry. Three upstream roughness arrays and two canyon width (W) to height (h) aspect ratios (AR = W / h = 1 and 3) were …

Influence Of Approach Flow Conditions On Urban Street Canyon Flow, Karin Blackman

Electronic Thesis and Dissertation Repository

The turbulent flow within a street canyon and the approaching boundary layer has been studied using idealized wind tunnel models and a semi-idealized field experiment conducted in Nantes, France. The effect of upstream roughness on street canyon flow (lateral length/height, L/h = 30) using either 3D (cube) or 2D (rectangular block) upstream roughness, of the same height as the canyon, has been studied for two streamwise canyon width to height aspect ratios (AR) of 1 and 3 using Particle Image Velocimetry. A further wind tunnel model of equivalent geometry to the field experiment was used to compare with flow data …

Physical Simulation Of Tornado-Like Vortices, Maryam Refan

Electronic Thesis and Dissertation Repository

Scaling ratios of simulations are essential to research the effect of tornadic winds on buildings and structures, in both experimental and numerical studies. In order to determine the proper scaling, access to wind fields of simulated and full-scale tornadoes is needed. For the first time here Doppler radar tornado velocity fields are analyzed and compared to experimental tornado-like vortices data in order to establish the scaling necessary to simulate tornadoes in a physical laboratory setting.

A prototype three-dimensional wind testing chamber capable of simulating tornadoes, named Model WindEEE Dome (MWD), was designed and built. Tornado-like vortices were simulated and investigated …

Near-Wake Flow Dynamics Of A Horizontal Axis Wind Turbine, Pooyan Hashemi Tari

Electronic Thesis and Dissertation Repository

Experiments have been conducted in a large wind tunnel set-up in order to study the flow structures within the near-wake region of a horizontal axis wind turbine. Particle Image Velocimetry (PIV) has been employed to quantify the mean and turbulent components of the flow field. The measurements have been performed in multiple adjacent horizontal planes in order to cover the area behind the rotor in a large radial interval, at several locations downstream of the rotor. The measurements were phase-locked in order to facilitate the re-construction of the three-dimensional flow field. Acquiring uniform particle distribution in the measurement planes as …