published_or_final_version / Mechanical Engineering / Master / Master of Science in Engineering

The effect of the ground on a rotor wake in forward flight has been investigated experimentally in the working section of an 8ft x Oft straight-through wind tunnel. A three bladed fully articulated rotor with a solidity ratio of 0.07 and diameter of 1.06m, powered by a hydraulic motor, has been tested at a height of 0.47 rotor diameter above a solid ground board which has an elliptical leading edge. Tests have been run at various low advance ratios (<0.1) with two collective pitch settings. A three-element hot wire anemometer probe has been used to measure the average value of the three components of velocity simultaneously in the forward half (advancing side) of the rotor wake and in the main stream surrounding it. The rotor wake and the ground vortices have been visualized by smoke. Surface flow patterns on the ground board have located the interaction region between the rotor wake and the oncoming flow on the ground board. Theoretical estimates of the flowfield based on Heyson's vortex cylinder model (Ref. 2) are compared with the experimental results. Both experimental results and theoretical estimates show that the ground-induced interference is an upwash and a decrease in forward velocity. The upwash interference' opposes the vertical flow through the rotor, and have large effects on the rotor performance in producing thrust. The streamwise interference decelerates the mainstream and becomes more noticeable as the wake boundary is approached.

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Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Cary L. Rivard / As populations of cities continue to increases, communities in the United States are implementing urban food systems including locally-cultivated produce. Urban and peri-urban farmers apply intensive production systems, including high tunnels, to better utilize limited space. Grafting tomato with vigorous rootstocks provides the potential for higher yields. Our first objective was to identify tomato rootstocks that improve productivity in high tunnel environments with no soilborne diseases in the Central U.S. Eight replicated high tunnel trials were conducted at four sites in northeastern Kansas in 2013 and 2014. We selected 'BHN 589' scion for all sites and evaluated seven rootstocks. Grafting with ‘Maxifort’, ‘Multifort’, ‘Arnold’, ‘DRO 131’, and ‘Colosus’ rootstocks resulted in significant increases in total fruit yield, which ranged from 40% to 73% when compared to nongrafted plants (P<0.05). No significant increases in yield were observed for ‘RT-1028’ and ‘RST-04-106’ rootstocks. Our results suggested that tomato growers that utilize high tunnels should be strategic when selecting rootstocks. Our second objective was to develop simple propagation techniques that yield high quality grafted transplants for small-batch propagators. Formation of adventitious roots (AR) from the scion can result in poor quality plants and loss of rootstock function/benefit. Greenhouse studies were designed to investigate how leaf removal (LR) affects AR formation and plant growth post-grafting. We applied three treatments, 0% LR, 50% LR, and 90% LR, to the ‘BHN 589’ scion and then grafted them onto ‘Maxifort’ rootstock. The experiment included 4 replicated blocks and was conducted in three different healing chambers. Our results indicate that both 50% and 90% LR significantly decreased AR formation in the low humidity chamber, but only 90% LR reduced AR formation in the chambers with high humidity (P<0.05). We measured plant growth 24 to 52 days post-grafting to understand how leaf removal affects transplant quality, growth, and development. Plants with 90% LR had significant growth reduction at day 24 but at day 52, only had reduced stem diameter and height compared to 0% LR. Total flower count was the same for all treatments. Leaf removal during grafting may be a viable method for propagating high quality, grafted transplants.

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Disertační práce představuje aplikaci hypoplastického konstitučního modelu při realizaci NRTM tunelu v prostředí městské zástavby s cílem obdržet "class A" predikce chování zeminového masivu. Tunely Královo Pole tvoří hlavní konstrukci severní části Velkého městského okruhu v Brně. Tunely o šířce 14 m a výšce 12 m jsou raženy v prostředí tuhých brněnských jílů s výškou nadloží v rozmezí 6 až 21 metrů. Materiálové parametry hypoplastického modelu kalibrované na výsledky laboratorních experimentů byly optimalizovány využitím dat geotechnického monitoringu a následně použity při simulacích tunelu. Po průchodu ražby profilu tunelu zvoleným úsekem staničení došlo k vyhodnocení prediktivních schopností a vhodnosti konstitučního modelu. Druhým konstitučním modelem použitým při simulacích průzkumné štoly a plain strain analýze tunelu je Mohr - Coulombův model. Metoda redukce napětí využitá v procesu optimalizace parametrů byla vyhodnocena formou porovnání s 3D simulacemi. K vyhodnocení posloužily simulace třech skutečných podzemních konstrukcí s nízkým nadložím realizovaných v prostředí tuhých jílů. Abstract The thesis demonstrates the application of a hypoplastic model in class A predictions of a NATM tunnel in an urban environment. The Kralovo Pole tunnel is a main construction of a northern part of a...