2 Kataoka, Ishii and Serizawa (I986 [ 11) analyzed the measurements of the local time-averaged interfacial area concentration in two-phase flow with a two-point conductivity probe. They considered the influence of the bubble velocity fluctuation on the measurement and directly transferred the mathematics concept of the local time-averaged interfacial area concentration into the measurable parameters. In the end of the derivation, however, the expression of the interfacial area concentration was

more »

... inappropriate due to the over-simplitication to the integration limits of the probability distributions. Consequently, the resultant interfacial area concentration may be signifkantly lower than the actual value. Since the formula is very important for the interpretation of experimental data, we feel it is necessary to provide a correction to the original work. According to Ishii concentration is given by where j denotes the j-th (1975 [2]), the definition of the time-averaged interfacial area (1) interface, Vi and n are the velocity and normal vector of the bubble interface as shown in Fig. 1, and At is the time interval for time averaging. If there is no DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best avaiiable original dOCtXmelllt. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, e x p m or implied, or assumes any legal liability or responsibiiity for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufactum, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not nefessarily state or mflect those of the United States Government or any agency tbereof.