Gaseous Explosions: VI—Flame and Pressure Propagation

Abstract

dots show experimentally determined values for the equivalent mixture C2H2 + C2H6. There is a close correspondence.In Diagram 11 the continuous curve shows the speeds of uniform movement of flame in a tube 2.5 cm. in diameter for propane-air,13 while the dotted curves show the speeds in the equivalent mixtures C5Hi2 + CH4 and 3 C5Hi2 + 2 H2.Though the agreement with the mixture containing hydrogen is not so good as with the hydrocarbon mixture, it still seems close when the great differences in the maximum speeds and the ranges of inflammability, of the constituent gases, pentane and hydrogen, are compared (see Diagram 1).Law of Flame SpeedsThese few results are instructive, and should prove of value as an aid to the law of flame speeds in further investigations. The law of flame speeds is a simple additive relationship for calculating the speed-percentage curves for complex inflammable gases from the curves with the simple constituent gases. This relationship has been developed in detail in a number of papers12 '4'3•11'34•35•27•36'37 and will not be discussed here, but a comparison of calculated and observed speed percentages will be of interest from the point of view of the present paper, and such a comparison is made in Diagram 12 for equimolecular mixtures of methane, hydrogen, and carbon monoxide, and will indicate the utility of the speed law.

Photographic Flame Studies in the Gasoline Engine

“…In surveying the literature, no description has been found of similar experiments made with the gasoline engine, but several investigators have described the results of such studies made in bombs (1,2,4,5,8,9,11). In 1928 Maxwell and Wheeler (8, 9) called attention to the need of flame studies of this type in a gasoline engine, but apparently the difficulties involved have not heretofore been overcome.…”

Gaseous Explosions

“…Figure12-Auto-Ignition Prevented by Decomposed Tetraethyl Lead. 2.61% Heptane-Air Mixture with 5% Decomposed Tetraethyl Lead Spark adjusted to eliminate waves; hot spot at 770°C.…”

Ratfish-Liver Oil as a Source of Vitamin A

“…After considerable preliminary work to determine the approximate amount of oil required daily for a total gain in weight of 25 grams in 8 weeks (one U. S. P. unit), the results given in Table III were obtained from which the animal unit for the sample of ratfish-liver oil tested is calculated to be about 0.03 gram.…”