Development of Computational Procedures for Reactive Gaseous Flows

本项目的目标是开发有限差分程序的反应气体流的模拟。计算程序适用于强激波后的高温气体和超音速燃烧气体，其中流体运动与化学过程相互作用很大。在这些超音速反应气体中，由于激波与边界层以及激波与化学过程之间的相互作用，预计将产生复杂的流场。在1989年，发展了一种模拟激波-边界层相互作用的计算程序，并成功地预测了激波管中反射激波与侧壁边界层相互作用的行为。将理想气体的计算方法推广到电离气体，并对激波管中电离氩的激波反射现象进行了数值模拟。在1990年，开发了一种有限差分程序来模拟可燃物流动。该方法采用FCT格式、Crank-Nicolson格式和半解析化学步骤相结合的方法，数值求解含化学项的薄层Navier-Stokes方程，预测反应流的行为。应用该模型预测了氢氧混合气中反射激波后的爆轰起爆现象。数值计算结果与实验结果的比较表明，本文方法可以再现爆轰起爆的几个特征方面。

The objective of the present project is to develop finite-difference procedures for simulations of reactive gaseous flows. The computational procedures are intended to apply for high temperature gas behind strong shock waves and for supersonic combusting gas in which fluid motions interact with chemical processes considerably. In these supersonic reactive gases, complicated flowfields are expected to be generated due to interactions between shock waves and boundary layers as well as those between shock waves and chemical processes. In 1989, a computational procedure was developed for simulations of the shock-boundary-layer interactions and it was applied to successfully predict behaviors of reflected-shock waves interacting with side-wall boundary layers in a shock tube. The procedure for ideal gas was extended for ionizing gas and numerical simulations were conducted for phenomena of shock reflection in ionizing argon in a shock tube. In 1990, a finite difference procedure was developed for simulations of combustible flows. This procedure predicts behaviors of reactive flows by numerically solving the thin-layer Navier-Stokes equations with modeled chemical terms by use of a combined method consisting of the FCT scheme, the Crank-Nicolson scheme and a semi-analytical chemical step. It was employed to predict detonation initiation phenomena behind reflected-shock waves in hydrogen-oxygen mixture. Comparisons between numerical results and experimental results indicate that thepresent procedure can reproduce several characteristic aspects of the detonation initiation.