International Expert in Fire Protection Engineering Visits the University of Maryland

International Expert in Fire Protection Engineering Visits the University of Maryland

International expert in fire protection engineering Charles “Charley” Fleischmann ’85, a professor emeritus from the University of Canterbury, New Zealand, returned to College Park last month to teach a seminar and meet students and faculty in the program. 

Fleischmann, an alum of the civil engineering and fire protection engineering undergraduate programs, is a principal research engineer in the Fire Safety Research Institute (FSRI), part of UL Research Institutes. His seminar, titled “Uncommon Compartment Fire Behavior” was held on September 12, 2025. 

“Charley Fleischmann is the perfect example of an engineer who combines academic skills to promote the field of fire safety through teaching and research with professional skills to promote the field through practical impact,” said Arnaud Trouvé, chair of the Department of Fire Protection Engineering (FPE). “It was a privilege to host him for the day, and the department is particularly proud of its legacy of training many of the world leaders in FPE!”

The visiting professor reminisced on his experience returning to his alma mater after building a successful career as a researcher and practitioner. 

“Returning to visiting FPE was a truly special experience. When I graduated in 1985, the department had just three faculty members and no graduate students,” said Fleischmann. “Seeing firsthand the growth in faculty, facilities, and research expertise was very impressive. The breadth and depth of the department today reflect an extraordinary evolution and commitment to advancing fire protection engineering.”

Below is the full abstract for Fleischmann’s seminar. 

Abstract: When considering compartment fire dynamics, fire engineers typically refer to the classical phases of fire development: the incipient phase, growth phase, flashover, fully developed phase, and finally the decay phase. However, in many real-world scenarios, this progression is interrupted. Common disruptions include occupant actions, fire service intervention, limited fuel availability, and restricted ventilation.

In recent years, FSRI has investigated several fire incidents where fire growth changed abruptly, resulting in measurable pressure increases—sometimes severe enough to cause structural damage. In some cases, the cause was not immediately apparent; in others, detailed post-fire investigations revealed the presence of unexpected flammable gases from previously unidentified sources.

This presentation focuses on incidents where ventilation was severely limited, preventing the immediate ignition of the pyrolysis gases due to insufficient oxygen. Under certain conditions, these gases can accumulate within the compartment and, upon ignition, produce a rapid pressure increase—referred to as an Over Pressure Event (OPE).

Research into OPEs has identified both common and uncommon features across experimental scenarios. These experiments can be broadly categorized into three types:

1. Events triggered by sudden changes in ventilation;

2. Events with extremely restricted ventilation that erupt into large external fireballs;

3. Events where fire growth abruptly transitions into high-velocity, horizontal, continuous flames from existing openings.

All of these are classified as OPEs and have been observed both in controlled experiments and on the fire ground. This presentation will explore the fire dynamics underlying OPEs and highlight potential warning signs that may precede such events.

November 6, 2025