DEVELOPMENT OF A COMPUTER CONTROLLED SHOCK TUBE SYSTEM FOR THE STUDY OF HIGH TEMPERATURE CHEMICAL KINETICS

点击翻译按钮获取中文摘要

The main goal of this study is to develop a reactor in order to obtain reliable chemical kinetic data at elevated temperatures. A computer controll system is employed to operate a shock tube automatically. The main functions of the system include : 1) controll the evacuation system by monitoring the vacuum level in the test section, 2) controll the high pressure gas supply in the driver section and the sample gas supply in the low pressure section, 3) generation of shock waves by operating solenoid valves for controlling the main and auxially pistons, 4) data storage transfered from a digital oscilloscope, determination of the shock wave temperature and pressure, conversion of the observed absorption intensity of ARAS into the absolute concentaration by use of the calibration curves for individual species, and chemical kinetic analyzes, and 5) operation of the emergency requirements (water, electricity, and gas leakage) . Performance tests have been already finished and all the functions are working very nicely. The automatic controll system for the shock tube study has been successful in excluding the errors due to manual operation or the fluctuation of the shock speeds associated with a standard type shock tube. The quality of the kinetic data thus obtained has been extensively improved : S/N ratio and errors due to random data fluctuations some time observed in shock tube runs can be improved by averaging the data for only several shots at the same shock speed. Moreover, an excimer laser photolysis method is used to obtain : the direct information of various atom/radical reactions.