Ph.D. Student Joshua Swann Wins Sheldon Tieszen Student Award
Joshua Swann, a Ph.D. Student in the Department of Mechanical Engineering (ME) focusing in Fire Protection Engineering (FPE), has been selected to be a recipient of the 12th International Symposium on Fire Safety Science Sheldon Tieszen Student Award, sponsored by the International FORUM of Fire Safety Directors. Swann was selected from a pool of 41 candidates, and will receive a certificate at a special ceremony during the Symposium, to be held in Lund, Sweden, June 12-16, 2017. At that time, Swann will present his research paper, entitled, "Controlled Atmosphere Pyrolysis Apparatus II (CAPA II):A new tool for analysis of pyrolysis of charring and intumescent polymers."
Swann, a Maryland native, is on track to complete his Ph.D. by December of 2018. "My future work entails experimentally gasifying a variety of widely used intumescent polymers in order to inform the construction of thermal transport numerical sub-models within the ThermaKin modeling framework," he said. "This work will also investigate the relationship between the char growth dynamics and the thermal transport within the decomposing materials."
Post-graduation, Swann intends to begin a career in applied research and fire accident investigation.
He is advised by Dr. Stanislav Stoliarov, an Associate Professor in the Department of Fire Protection Engineering at UMD. Additionally, ME/FPE Ph.D. Candidate, Yan Ding, also contributed a great deal of work to this research.
A new gasification apparatus has been developed to enable a comprehensive analysis of pyrolysis of charring and intumescent materials. This apparatus provides well defined boundary conditions and highly resolved measurements of mass, temperature and sample profile evolution of a disk-shaped 0.07 m diameter material sample exposed to radiant heat. All measurements are collected simultaneously, in a single experiment, and recorded as a function of time. The oxygen concentration in the pyrolysis zone is controlled and can be reduced below 1 vol.% to ensure that the measurements are free of oxidation effects. The radiation from an external conical heater has been carefully characterized to account for changes in the sample surface position, including the surface’s angular orientation. Using an empirical expression, the radiation heat flux can be predicted with less than 2% error based on the known surface position and heat flux set point. The NIST Fire Dynamics Simulator (FDS) has been utilized in the direct numerical simulation mode to investigate convective losses from the sample surfaces. The convective heat transfer coefficient computed for the top (radiation exposed) surface has been found to be dependent on the surface position; its space-averaged value has been validated against experimental measurements. The capabilities of the apparatus are demonstrated using poly(vinyl chloride). It is shown that the apparatus provides repeatable data necessary for modeling of transport processes inside pyrolyzing intumescent solids. Non-one-dimensional nature of these processes is discussed.
Congratulations Joshua, and keep up the good work!
April 20, 2017