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Gaseous Detonation Onset and Decay Transient Modesтезисы доклада
- Авторы: Smirnov Nickolay, Nikitin Valeriy, Mikhalchenko Elena, Azatyan Vylen
- Сборник: International Workshop on Explosions and Reactive Flows. Conference Handbook. July 16-17, Beijing, China
- Тезисы
- Год издания: 2022
- Первая страница: 18
- Последняя страница: 20
- Аннотация: Detonation is a complex phenomenon due to a three-dimensional wave structure with an inhomogeneous dynamic wave front. The inhomogeneous front contains pressure triple points moving along it. If the triple points move in the vicinity of a soot-covered detonation tube surface, shear forces from them mark a fishnet-like pattern on the inner walls of the tube. This pattern is known as a detonation cell. As the leading shock front propagates downstream, the triple points alternate. Simultaneously, the transverse waves oscillate perpendicular to the direction of propagation. Sizes of these detonation cells have been found to be one of the most important parameters in detonation research. The lecture presents the results of theoretical and experimental research of transient modes between deflagration and detonation. The problems of detonation onset caused by accelerating flame or reflected shock waves are discussed. The lecture considers the influence of a hydrocarbon inhibitor on the developed detonation in a hydrogen-air or syngas-air mixture, on the destruction of the detonation front and subsequent decay of detonation cells. The chemical reaction of hydrogen with air is a classic example of a branching chain reaction. In chain reactions, radicals play an important role as intermediate products of elementary stages. Without the mediation of radicals, the final product is not formed. The most mobile and active radical is atomichydrogen H which plays an important role in nearly all combustion mechanisms involving hydrogen or its compounds. If its activity is reduced with a help of some chemical additive, the reaction will slow down. A slowdown in the reaction does not diminish its energy: the additive could be flammable itself. A decrease in the hydrogen atom activity can be achieved in many ways, one of which is using an unsaturated hydrocarbon; its reaction with H eliminates the double bond between the carbon atoms. The resulting alkane radical is much less active than atomic hydrogen. The amount of inhibitor could be several percent by volume.
- Добавил в систему: Стамов Любен Иванович