CFI Fire Dynamics & Behavior Flashcards

What term describes the minimum temperature at which a liquid fuel produces enough vapor to ignite momentarily when an ignition source is applied?

Answer: Flash point

The flash point is the lowest temperature at which a liquid produces sufficient vapor to form an ignitable mixture near its surface.

Which heat transfer mechanism involves the movement of hot combustion gases rising from a fire and spreading heat throughout a compartment?

Answer: Convection

Convection transfers heat through the physical movement of hot gas molecules, causing them to rise and circulate within a compartment.

The transition from a localized fire to full room involvement where all combustible surfaces ignite simultaneously is called:

Answer: Flashover

Flashover occurs when radiant heat from the hot gas layer raises all exposed combustible surfaces to their ignition temperature simultaneously.

What condition occurs when fresh air suddenly enters a vitiated (oxygen-depleted) compartment containing hot unburned gases, causing a rapid deflagration?

Answer: Backdraft

Backdraft is a smoke explosion caused by the sudden introduction of oxygen into a superheated, oxygen-depleted compartment full of unburned fuel gases.

Which of the following best describes the 'heat release rate' (HRR) in fire dynamics?

Answer: The rate at which a fire produces thermal energy measured in kilowatts

Heat release rate (HRR), measured in kilowatts or megawatts, is the single most important variable in fire dynamics as it determines fire growth and severity.

In fire investigation, 'char depth' measurements are primarily used to:

Answer: Estimate relative burn time and intensity to help identify fire origin

Char depth provides investigators with comparative data about relative burn duration and heat intensity at various locations, aiding in origin determination.