1994 Volume 34 Issue 6 Pages 461-467
The objective of this study is to develop a new velocimeter utilizing the hydrodynamic drag of a sphere which is applicable to velocity measurement of high temperature molten flow. Although the drag coefficient CD is required for the evaluation of drag, has not been studied for a fluid flow with high turbulence intensity and turbulence scale typical of ironkaming and steelmaking processes. Therefore CD was measured using a sphere placed in a wind tunnel equipped with a turbulence generator and correlated as a function of Reynolds number Re and turbulence intensity Tu. The effect of turbulence scale was found to be negligible.
A new velocimeter using a sphere was developed and its applicability was examined in cold models such as an air jet of Tu≅2%, a water jet of Tu=30-40%, and a water-air bubbling jet of Tu=40-50%. Agreement between the results obtained by the present velocimeter and those obtained by existing velocimeters, for example, laser Doppler velocimeter, hot wire anemometer and pitot tube was quite reasonable. Velocity measurement in a mercury-air bubbling jet also revealed the possibility of the usage of the present velocimeter for high temperature and high turbulence molten metal flow in metallurgical reactors.
