An Investigation of the Autoignition of a Combustible Mixture Due to the Presence of a Heated Surface

Citation

Schurman, Glenn August (1950) An Investigation of the Autoignition of a Combustible Mixture Due to the Presence of a Heated Surface. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/3QCH-T047. https://resolver.caltech.edu/CaltechETD:etd-03272007-084015

Abstract

An experimental investigation regarding the nature of the hydrogen-oxygen reaction in the vicinity of a heated surface is described. The experimental work was conducted at atmospheric pressure in a shallow rectangular combustion chamber. The upper surface of this chamber is heated to temperatures ranging from room temperature to 1615° R; the lower surface is maintained at a constant temperature of 550° R. The temperature distribution of the mixture between the two plates is the primary experimental measurement. This measurement was made with a Mach-Zehnder optical interferometer. The maximum temperature of the upper plate at which experiments were made was 1615° R. The maximum temperature at which interferograms were taken was limited by the presence of a nonuniform temperature distribution along the light path. It was found that the central area of the heated surface of the combustion chamber could be held at a temperature of 1710° R without an explosion occurring. The chemical reaction could not be detected below an upper plate temperature of 1500 ± 10° R. There is evidence that large composition gradients exist in the combustion chamber. These gradients persist for a much longer time than that predicted from the diffusion theory. Accordingly, the overall rate at which the reactants combine is much lower than that expected. The exact reasons for the suppression of the explosion and the reduced reaction rate are not understood. Two possible explanations are suggested.

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