Volumetric Flow Rate Ratio Research Articles

Gas-Liquid Slip Ratio and MHD Pressure Drop in Two-Phase Liquid Metal Flow in Strong Magnetic Field

The gas-liquid slip ratio and the MHD pressure drop in the two-phase liquid metal flow under a strong magnetic field are treated in relation to the distributions of the gaseous phase and the fluid velocity. From NaK-N2 two-phase experiments, it is found that: 1. The ratio of the two-phase MHD pressure drop to that of the homogeneous non-slip two-phase flow model is independent of the applied magnetic field strength and the channel geometry (ratio of wall thickness to channel width) and is presented as a function of the ratio of the gas-liquid volumetric flow rate. 2. The void distribution is affected by the applied magnetic field. The gas bubbles may be pushed away towards the both side walls due to the pinch effect, resulting in the increase of the ratio of the mean void fraction to the one at the channel center with the increasing applied magnetic field. 3. The gas-liquid slip ratio is not directly dependent on the applied magnetic field strength and the channel geometry and is presented as a function o...

プロパン酸素炎による鋼材の溶接について(第2報)

Welding of steel with propane-oxygen flame became possible, when both the enriched oxygen flame and the welding rod containing sufficient deoxydizing elements were used.The objects of this investigation are to find out the proper ratio of volumetric flow rate of oxygen to propane in propane-oxygen flame for the greatest flame intensity to melt steel plate, and to find out another way to increase the intensity of the propane-oxygen flame. The intensity of flame was experimentally evaluated with the time to start meltintg in the same way described in the previous report.Three kinds of improved flames were examined as below.i) Thermal cracked propane-oxygen flame : propane begins to convert into hydrogen, methane, ethylene and propylen by thermal cracking at 600°C and is cracked completely at 900°C, ii) preheated propane-oxygen flame: the burning velocity of propan oxygen gas mixture becomes high by preheating under 550°C, and iii) propane-acetylene-oxygen flame: in place of a part of propane is added acetylen having higher burning velocity than propane.The results were shown as follows;1) The effect of preheating on an increment of intensity of flame is the greatest of those of any other flames. The effect is obtained at lower preheating temperature than thermal cracking temperature.2) Each minimum time to start melting of the propane-oxygen flame and three improved flames with various flow rate of oxygen is obtained at the location inside the inner cone with a stoichiometrical oxygen mixture for complete combustion.