Introduction to "To the Question of Energy Use of Detonation Combustion" By Ya. B. Zel'dovich
Ya. B. Zel’dovich (1914–1987) made numerous contributions [1] to the theory of detonation, beginning with his very well known and widely translated article [2] on detonation structure that first introduced the standard Zel’dovich-von Neumann-Doring (ZND) model of shock-induced combustion. Even at that early stage of detonation research, Zel’dovich was also considering the application of detonations to propulsion and power engineering. He published these ideas in another paper [3] that has been virtually unknown in the West and has apparently remained untranslated until now. We are indebted to Sergey Frolov of the N.N. Semenov Institute of Chemical Physics for first bringing this article to our attention. We believe that the focus of this paper, which is the application of detonation waves to power generation and propulsion, is very relevant to the current activity on pulse detonation engines. In particular, Zel’dovich was apparently the first researcher to consider the questions of the relative efficiency of various combustion modes, the role of entropy production in jet propulsion, and the distinction between unsteady and steady modes of detonation in power engineering and propulsion applications. Even 60 years later, we believe that his results are relevant and can be of value in modern discussions on thermodynamic cycle analysis of detonation waves for propulsion [4]. For these reasons, we have arranged for the paper to be translated and suggested that it be published by the Journal of Propulsion and Power.
Dependence on the sectional shape of tube for propagation behavior of three-dimensional detonation
This paper is concerned with numerical simulation on propagation behavior of three-dimensional detonations in square tubes. Influence on motion trajectories of high pressure region (shock triple points) due to the change of aspect ratio of tube is solved by a finite difference method which consists of the semi-implicit MacCormack method and Non-MUSCLE type TVD scheme in order to prevent numerical stiffness and Gibb’s phenomena. Reaction mechanism utilized in this study is the Nagoya model constructed for the stoichiometric hydrogen and oxygen gas mixture. It was found from numerical results that distinction in propagation mode could be explained from the relation between the geometric form of the tube section and the behavior of triple points. Moreover, it was shown that the transition of the configuration and the mode of propagation might not be settled causing the aspect ratio of the section.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.