The pressure drop oscillation is analyzed by using a lumped parameter nonlinear model in this paper.The results show that the pressure drop type instability can be described by a second order differential equation.The effect of operation conditions on the pressure drop oscillation can be expressed by two dimensionless parameters E,η Model results agree qualitatively with experimental results.
A method is proposed for measuring the thermal conductivity of matter which varysnonulinearly with temperature. Existing measuring equipment can be used without anychange in this method and the thermal conductivity of infinite slab, infinitely long cylinderand sphere can be described by the same equation. The thermal conductivity of fly ash nat-urally deposited was measured and the dependence of thermal conductivity on temperatureis obtained by using this method. Experimental result agreed reasonably with the predictedresults by the predictive relation derived in this paper.
