scenario-based

Fire Behavior and Combustion

Professor James Golden

Importance of knowing the difference between intensive and extensive properties in the scenario

Pressure, density, concentration, boiling point, chemical formula, and odor is the difference between mass, volume, length, and enthalpy. The properties stated is the difference between intensive and extensive properties. Intensive property is a property of matter which relies on the type of matter in a sample rather than the amount. Extensive properties refers to the matter which has dependency on mass (Robtaille, & Crothers, 2019). This aids in determining the materials which can easily catch fire and can easily be extinguished.

Difference between conduction and radiation

With conduction, heat transfer takes place between objects by direct contact. It is the process in which heat energy is transmitted through collisions between neighboring atoms or molecules. Radiation refers to the energy which comes from a given source and travels in space at the rate of light. Energy is transmitted in the form of waves through space.

How heat flows from hotter to colder affect fire fighting

Heat transfers through the colder material, the older the material the more the rate of heat transfer will take place. This makes it hard for fire fighters since they are thus required to begin extinguishing fire from the parts which have not ignited which tends to make it hard to access.

What is the difference between thermally thick and thermally thin?

Thermally thin materials are materials in which there is no major heat gradient throughout their thickness. Basically, the entire volume is heated at the same temperature at all times. Thermally thick is the solid which absorbs heat energy more readily near the surface and does not transfer it as quickly through the material to the other side (Johansen, et al., 2016).

What is radiative heat transfer?

Radiative heat transfer refers to the energy which is emitted by matter in the form of photons as well as electromagnetic waves (Cuevas, & Garcia-Vidal, 2018).

Why is it important to understand the effects of pain from radiant exposure?

Safeguarding people from radiant heat is essential since exposed people quickly feel unbearable pain, and also second degree burns, making safe egress impossible.

How does fire affect building structures, and how can that knowledge be used when fighting a structure fire?

Physical and material property changes take place in the structural steel framing during a fire event. Thermal elongation, strength reduction as well as a reduction in stiffness can take place. Therefore when fighting structure fire they should consider thermal conductivity of steel which would aid in reducing temperatures.

References

Cuevas, J. C., & García-Vidal, F. J. (2018). Radiative heat transfer. Acs Photonics, 5(10), 3896-3915.

Johansen, J. M., Jensen, P. A., Glarborg, P., Mancini, M., Weber, R., & Mitchell, R. E. (2016). Extension of apparent devolatilization kinetics from thermally thin to thermally thick particles in zero dimensions for woody biomass. Energy, 95, 279-290.

Robitaille, P. M., & Crothers, S. J. (2019). Intensive and extensive properties: Thermodynamic balance. Physics Essays, 32(2), 158-163.https://doi.org/10.4006/0836-1398-32.2.158