fire dynemics 3 questions

Show all calculations and use an EXCEL spreadsheet

1. – You are hired by an industry that owns a building with a floor area of 6 m by 10 m and a ceiling height of 4 m. The walls, floor, and ceiling are concrete 15 cm thick. Gasoline is spilled on the floor and ignites due to a worker casually lighting a cigarette. The building has a door which is 1.2 m wide by 2.5 m high.

(a) What is the energy release rate at flashover (MW)?

(b) What is the maximum area of spill (m²) if flashover is to be prevented?

Note: Perform your calculations 10 minutes after ignition and use combustion efficiency of 0.7.

2 .- A room has dimensions of 20 m by 20 m by 3.05 m high. A fire develops in the room with a constant energy release rate of 900 kW. Compute the time (sec) that it will take the smoke layer to be 1.5 m from the floor for two conditions: (a) when leakage areas are located at floor level; and (b) when the leakage is at roof level.

3. – A closed room is 5 m high and contains a fire with a plume mass flow rate of 5 kg/s at a height of 2.5 m and an upper layer temperature of 400^oC. There is an opening at floor level 1 m wide and 2.5 m high. Your assignment is to find the required ceiling ventilation area if the smoke is not to come closer than 2.5 m from the floor.