Equation Of State Of Carbon Monoxide At High Pressures And Temperatures

In this thesis, equation of state of liquid carbon monoxide at high pressures and temperatures is researched by experiment and theoretical ways. The dynamic high-pressure technique is applied to multiply compress of the liquid carbon monoxide to thermodynamic states of high pressures and temperatures, and the optical analysis technique is used to directly measure the equations of state for the first-shocked, the second-shocked, the third-shocked states. The radiation temperature and the diversification of temperature with time are also measured. Based on the variational perturbation theory of molecular fluid and EOS model of three-phase carbon, Hugoniot EOS corresponding to multi-shock processes are calculated, which are compared with those measured. The details of the measurement technique and calculation method are described, and such a scheme can be applied to other molecular fluids to achieve higher pressures and larger compression ratios. The achievements are summarized as follows.1,The cryogenic target technique and an optical analysis technique are combined to measure multi-shock Hugoniot equations of state of liquid carbon monoxide. The pressures of the first-shocked, the second-shocked, and the third-shocked states are respectively 19. 36GPa, 60. 36GPa, and 71. 02GPa. At the pressure of 71. 02GPa, the maximum compression ratio of volume reaches 3.5, which is 20% higher than the ever reported maximum value.2,If carbon monoxide is non-reactive, the predicted specific volume by molecular fluid theory are nearly twenty percent more than the measured results, which is attributed to the molecular dissociation reactions of carbon monoxide under shock compressions.3,The shock temperature of liquid CO at first shock of 19.36GPa is measured by pyrometer technique, and the obvious increase of temperature with time is observed. It shows that the chemical reaction of liquid CO under shock is taking place, with heat released.4,Based on the molecular fluid variational perturbation theory and EOS of carbon, EOS of pure molecular liquid CO are calculated. When liquid CO is sandwiched between aluminium and sapphire and impacted by aluminium flyer, its 1st,2nd,and 3th multi-Hugoniot states are determined by theoretical calculation. When the shock-induced disociation reaction is considered, the carbon in the products is supposed to be respectively solid diamond, solid graphite, and liquid carbon. The calculation results are compared with experimental data, and the discrepancy is found. The molecular fluid variational perturbation theory was widely used to discribe molecular fluids, and its accuracy is proven to be within 2% by the experiments. So, we conclude that the properties of shock-induced carbon should be very different from those described by the three-phase model, and further study on this subject is needed. Besides that, the difference of shock wave velocity in theoretical calculation and experiment is likely to affecting the theoretical data.