Since establishing UL’s Fire Safety Research Institute (FSRI) Fellowship in 2017, the team has supported six graduate students from the University of Maryland (UMD) Department of Fire Protection Engineering (FPE) program. Each research fellow is expected to complete their proposed research project under the supervision of both a member of UMD faculty and a supervisor at FSRI.
Although Grayson Bellamy and Matt Harris began their fellowships in the middle of the COVID-19 pandemic, they found ways to overcome unique challenges to conduct their proposed research projects. Grayson and Matt had the opportunity to share how they conducted the research and their findings this week during NFPA’s Conference and Expo Student Poster Session in Boston, MA.
Grayson’s thesis project, “Development and Improvements to the Controlled Atmosphere Pyrolysis Apparatus (CAPA III),” aims to quantify and validate thermophysical properties of materials throughout the thermal decomposition process. Although many properties can be obtained through standardized methodologies, quantifying the thermal transport properties at elevated temperatures and through pyrolysis remains a difficult and uncertain task. The use of the bespoke Controlled Atmosphere Pyrolysis Apparatus (CAPA) has been identified as a potential solution to this problem, but data has thus far not been reproduced. The direct outputs of this device are the back surface temperature of a sample and mass loss rate which provide the inputs necessary for extracting meaningful data from a comprehensive fire model. Notable improvements to this design include integral water cooling of the gasification chamber, upgraded diagnostic equipment, and greater capacity for data acquisition. Characterization of the device indicated that the thermal boundary conditions were comparable to previous versions, allowing direct comparison of test data. Experiments were conducted on oriented strand board (OSB) and poly(methyl methacrylate), both of which were experimented on with a previous version of CAPA. The overall replication of this previous data was excellent, giving confidence that the methodology is meaningful, and the results can be reproduced. Future work will look at extracting properties from this data using an inverse modeling approach and the impact of sample preparation methods on results.
Grayson is set to defend his thesis in August and will graduate with his masters following the fall semester.
Matt’s thesis project, “Predicting the Temperature Increase of Residential Siding and Decking Materials in the WUI Due to External Heat Flux,” measured and quantified the thermophysical properties of several common siding and decking materials found in the wildland urban interface (WUI). These siding and decking materials were then exposed to a radiant panel at constant heat fluxes to mimic the incident radiant heat flux from an approaching wildfire. The back side temperature increase of these samples was measured using a type K thermocouple, and the backs and sides of the samples were insulated. In the last phase of this project, Fire Dynamics Simulator (FDS) was used to create a model for predicting the temperature increase in siding and decking materials from an external heat flux. This model was assumed to be one-dimensional and used the thermophysical properties measured during the first phase as material property inputs. These model predictions were compared with the temperature data from the radiant panel testing phase. Overall, this model was accurate in predicting temperature increase in siding and decking materials during the shorter exposure times. The model overpredicted the temperature increase during longer exposure times. These overpredictions were likely due to simplifications in the model which neglected charring and included only constant material properties.
Matt successfully defended his thesis last month and received his master's degree from UMD. He has accepted a full-time position in Dallas, TX and will be moving on later this summer.
