Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1933. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed July 12, 2010) Includes bibliographical references (p. 55) and index (p. 56).

abstract: Gas turbines have become widely used in the generation of power for cities. They are used all over the world and must operate under a wide variety of ambient conditions. Every turbine has a temperature at which it operates at peak capacity. In order to attain this temperature in the hotter months various cooling methods are used such as refrigeration inlet cooling systems, evaporative methods, and thermal energy storage systems. One of the more widely used is the evaporative systems because it is one of the safest and easiest to utilize method. However, the behavior of water droplets within the inlet to the turbine has not been extensively studied or documented. It is important to understand how the droplets behave within the inlet so that water droplets above a critical diameter will not enter the compressor and cause damage to the compressor blades. In order to do this a FLUENT simulation was constructed in order to determine the behavior of the water droplets and if any droplets remain at the exit of the inlet, along with their size. In order to do this several engineering drawings were obtained from SRP and studies in order to obtain the correct dimensions. Then the simulation was set up using data obtained from SRP and Parker-Hannifin, the maker of the spray nozzles. Then several sets of simulations were run in order to see how the water droplets behaved under various conditions. These results were then analyzed and quantified so that they could be easily understood. The results showed that the possible damage to the compressor increased with increasing temperature at a constant relative humidity. This is due in part to the fact that in order to keep a constant relative humidity at varying temperatures the mass fraction of water vapor in the air must be changed. As temperature increases the water vapor mass fraction must increase in order to maintain a constant relative humidity. This in turn makes it slightly increases the evaporation time of the water droplets. This will then lead to more droplets exiting the inlet and at larger diameters. / Dissertation/Thesis / M.S. Aerospace Engineering 2013

Class of 2013 Abstract / Specific Aims: To determine if temperature and direct sunlight influence the rate of evaporation of normal saline in 100mL IV bags. Methods: Four study groups were created; refrigeration, dark shelf, shelf near window, and EMT box simulation. 80 bags (50 ml bags of normal saline) placed in different areas of temperature change and sun exposure. 20 of the bags stored in a drawer in a refrigerator. 20 stored on a shelf in a dark temperature controlled room. 20 stored next to a window in direct sunlight, and 20 stored outside where temperature and sun exposure will be highest in an EMT simulated box. Weights were recorded (in gms) weekly for 8 weeks using an analytical balance. Each saline bag was weighed individually and recorded at the time of measurement. Main Results: Rates of volume loss were lower in the normal saline IV bags stored in a refrigerated environment compared to the other two groups stored at room temperature and the one group stored in outside conditions (p<0.001). IV bags stored at room temperature exposed to light had the second lowest rate of loss compared to the other two groups (p<0.001 compared to outside conditions and p=0.003 compared to closed drawer). Bags stored at room temperature in a closed door had the third lowest rate of loss (p<0.001). Conclusion: Rate of fluid loss from IV normal saline bags appears to be temperature sensitive and storage of these bags may have an impact on shelf life of the product.

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Indiana University-Purdue University Indianapolis (IUPUI) / This thesis is a comprehensive investigation into the mechanics of evaporation experienced by planetesimals during accretion, a planet-building process. The evaporation events that these rocky bodies experience govern their chemical evolution, impacting the chemistry of the final body – a planet. Studying these planet-building processes is notoriously difficult (e.g., Sossi et al., 2019). There are still many unknowns surrounding what controls the degree of evaporation these bodies experience, and the resulting chemical signatures. The current study was designed to attempt to define some important parameters that govern silicate melt evaporation. Here, we isolate and evaluate the effects of (1) pressure, (2) oxygen fugacity and (3) the activity coefficient of MgO on evaporating planetesimals through a series of computational models. The model introduced in this study, the ƒO2 Modified KNFCMAS Model, uses a robust stepwise routine for calculating evaporative fluxes from a shrinking sphere. The modelling results are then compared to data from partial evaporation experiments of synthetic chondrite spheres to demonstrate the validity of this model, and to expose unknowns about the physicochemical conditions of high temperature silicate melts experiencing evaporation (in this case, the effective pressure, and the activity coefficient of MgO). Major element-oxide and isotope data from the models yielded two main conclusions concerning planetesimals: (1) the rate of evaporation is controlled by pressure and oxygen fugacity and (2) the chemical composition of the residual melt is controlled by oxygen fugacity and the activity coefficient of MgO. Results from computational modelling and evaporation experiments were used to determine an approximation for the activity coefficient of MgO in a simplified chondritic composition, as well as the effective pressure experienced by the evaporating spheres during the partial evaporation experiments. This study outlines the controls on planetesimal chemistry during evaporation and provides a more accessible means of studying these complex processes.

Biodiesel has been proposed as a substitute for diesel given that biodiesel has lower net average greenhouse gas emissions than diesel. Additionally, alcohol may be added to biodiesel to improve biodiesel’s performance in a diesel engine as well to reduce engine emissions. This work will study the droplet evaporation process of alcohol-biodiesel blends. Due to alcohol’s polar nature and the fatty acid methyl esters’s (FAME) slightly polar nature, an appropriate method must be chosen to represent the evaporation process of a non-ideal mixture. The vapour-liquid equilibria was modelled in two ways: the first method uses only Raoult’s Law, while the second method uses Raoult’s law modified with activity coefficients calculated using the UNIFAC method. The comparison of the modelled results with experimental vapour-liquid equilibria data has shown that activity coefficients calculated using the UNIFAC method are able to accurately represent alcohol-biodiesel systems. Droplet evaporation experiments have been performed for biodiesel-propanol and biodiesel-pentanol blends at temperatures of 450°C and 700°C with the alcohol concentrations of 5%, 10%, 15%, and 20%. Additionally, the droplet evaporation was numerically modelled using two different models to represent the liquid state: a model with a well-mixed liquid phase and a model which includes component diffusion in the liquid phase. Comparing the experimental droplet temperatures to the numerical models has shown that the diffusion-limited model best represents the droplet evaporation process, suggesting that some of the alcohol components remain in the center of the droplet even when the droplet temperature is greater than the boiling temperature of the alcohol. This was further confirmed by observations of bubbling within the droplet during evaporation of the biodiesel-alcohol blends, in which there were both small bubbles and large bubbles forming. The formation of large bubbles has shown to correspond with the difference between experimental droplet diameter and the diffusion-limited model’s droplet diameter.

Daily pan evaporation data are poorly collected. This thesis uses different methods to correct these inadequate data, and make them usuable for many scientific purposes. Nine Southeastern region states with a total of 83 evaporation sites were chosen to represent the study region. These data were corrected to be serially complete and homogeneously sound for the entire stations' period of record. After the data corrections were made, temporal and spatial analyses were completed. These analyses help display the functionality of these corrected data. This study provides an enhanced understanding of the evaporation regime of the Southeastern region and makes an enormous amout of usable data available. These data sets are contributed to the literature for use in future research, and are distributed to all State and Regional Climate Centers in the Southeastern region.

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