Physico-Chemical Processes Behind Shock Fronts

Citation

Harshbarger, Frederick Clay (1957) Physico-Chemical Processes Behind Shock Fronts. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/YYJF-HM80. https://resolver.caltech.edu/CaltechETD:etd-07132004-150103

Abstract

Part I: Introduction to the Study of Physico-Chemical Phenomena by the Use of Shock Tubes. The use of the shock tube for the determination of physico-chemical parameters at elevated temperatures is surveyed. We first describe the principles and performance of various shock-tube designs. Next the use of a number of measuring techniques suitable for shock-tube studies is discussed. This section is followed by a summary of representative determinations of physico-chemical parameters behind incident and reflected shock waves. Part II: Experimental Studies of Reactions Behind Shocks. The original experimental research involved the study of two chemical reactions. First we describe an unsuccessful attempt to produce hydrazine from ammonia. Second, carbon formation from acetylene is considered theoretically and experimentally. In the calculations, the state of the gas is determined behind the incident and reflected shocks, preceding chemical reaction. Estimates are made for the minimum times spent by the gas in a uniform state at the elevated temperatures behind reflected shocks. The experimental studies led to a new method for making simultaneous light emission and absorption measurements. A kinetic interpretation is given to the induction time necessary to form carbon after the passage of the reflected shock. Spectroscopic studies are presented which indicate that the emitted radiation associated with carbon formation follows a blackbody distribution law. A two-color method has been developed for the determination of temperature as a function of time behind carbon-forming shocks.

Thesis Files