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Full-Text Articles in Engineering

Modeling Soot Oxidation And Gasification With Bayesian Statistics, Alexander Jon Josephson, Neal D. Gaffin, Sean T. Smith, Thomas H. Fletcher, David Lignell Jan 2017

Modeling Soot Oxidation And Gasification With Bayesian Statistics, Alexander Jon Josephson, Neal D. Gaffin, Sean T. Smith, Thomas H. Fletcher, David Lignell

Faculty Publications

This paper presents a statistical method for model calibration using data collected from literature. The method is used to calibrate parameters for global models of soot consumption in combustion systems. This consumption is broken into two different submodels: first for oxidation where soot particles are attacked by certain oxidizing agents; second for gasification where soot particles are attacked by H2O or CO2 molecules. Rate data were collected from 19 studies in the literature and evaluated using Bayesian statistics to calibrate the model parameters. Bayesian statistics are valued in their ability to quantify uncertainty in modeling. The calibrated consumption model with …


A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George Nov 2006

A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George

Theses and Dissertations

The weathering of plastics and composites is a problem because of the loss of both physical and mechanical properties that it causes in these materials. But this weathering effect has been difficult, and in some cases, impossible to characterize without the destruction of the plastic or composite part. Clearly a rapid, reliable, and non-destructive test for the extent of the weathering damage is critically needed. A recent problem that arose at Superyacht Solutions, a boat repair company in Australia, required a solution to just this problem. Such a test was developed for Superyacht Solutions, and is being applied across a …


An Analysis Of Microstructure And Corrosion Resistance In Underwater Friction Stir Welded 304l Stainless Steel, Tad Dee Clark Jun 2005

An Analysis Of Microstructure And Corrosion Resistance In Underwater Friction Stir Welded 304l Stainless Steel, Tad Dee Clark

Theses and Dissertations

An effective procedure and parameter window was developed for underwater friction stir welding (UWFSW) 304L stainless steel with a PCBN tool. UWFSW produced statistically significant: increases in yield strengths, decreases in percent elongation. The ultimate tensile strength was found to be significantly higher at certain parameters. Although sigma was identified in the UWFSWs, a significant reduction of sigma was found in UWFSWs compared to ambient FSWs. The degree of sensitization in UWFSWs was evaluated using double loop EPR testing and oxalic acid electro-etched metallography. Results were compared to base metal, ambient FSW, and arc welds. Upper and lower sensitization localization …


Improving The Accuracy Of Predicting Effectiveness Factors For Mth Order And Langmuir Rate Equations In Spherical Coordinates, Jianhui Hong, William C. Hecker, Thomas H. Fletcher Jan 2000

Improving The Accuracy Of Predicting Effectiveness Factors For Mth Order And Langmuir Rate Equations In Spherical Coordinates, Jianhui Hong, William C. Hecker, Thomas H. Fletcher

Faculty Publications

Char oxidation is often modeled using an mth order intrinsic reaction rate in conjunction with an effectiveness factor to account for intraparticle diffusion of gas species. This approach involves the use of a general modulus (MT) and using the first-order curve of effectiveness factor vs MT. This method was originally referred to as the general asymptotic solution. It has been suggested that a simple Langmuir rate equation is more suitable for modeling the effects of pressure on char reactivity. Therefore, several methods of developing general moduli for the Langmuir rate expression are shown. The general asymptotic …