Combustion of Methanol Droplets in Air-Diluent Environments with Reduced and Normal Gravity

Table 1

Diluent mole fractions required for the onset of Case 1 (negligible heat release), Case 2 (appreciable heat release that occurred only when the igniters were energized and near a droplet), or Case 3 (sustained combustion after the igniters were deenergized and retracted).

Diluent	Fuel	𝑋𝐷 Case 1 μg	𝑋𝐷 Case 2 μg	𝑋𝐷 Case 3 μg	𝑋𝐷 Case 1 1-g	𝑋𝐷 Case 2 1-g	𝑋𝐷 Case 3 1-g
He	1-Propanol	0.40	0.30	0.20	0.30	—	0.20
	Methanol	0.50	0.40	0.20	0.40	0.30	0.20
CO2	1-Propanol	0.50	0.40	0.20	0.40	0.30	0.10
	Methanol	0.50	0.40	0.20	0.30	—	0.20
Xe	1-Propanol	0.90	0.80	0.50	0.60	0.50	0.20
	Methanol	0.85	0.80	0.50	0.80	0.70	0.40