PREDICTION OF BURNING CONSTANTS OF SUSPENDED HYDROCARBON FUEL DROPLETS

An improved method of predicting the burning constants of suspended hydrocarbon drops based on a modified theoretical equation is presented. The burning constants calculated with this method show an average deviation of 5·6 per cent from the experimental values for 19 hydrocarbon fuels. This deviation is comparable to the error involved in the experimental determination of the burning constants. At the 95 per cent confidence level the calculated results are accurate to ±0·0013 cm2 sec. To develop this method, burning constants were calculated from a theoretical equation in eight different ways based on the combinations of two assumed flame temperatures and four average thermal conductivities. The eight sets of burning constants so calculated were compared with the experimental values and found to show average deviations from the experimental of from 9·8 to 34 per cent. In order to obtain closer agreement with experiment the theoretical equation was modified. The constants in the modified equation were determined by a least squares analysis constants calculated from the modified equation and experiment l ranged from 5·6 to 94 per cent. The method which yields the closest agreement between the experimental and calculated burning constants is presented in detail. © 1969.