Abstract
This paper deals with a numerical simulation of the flow with some narrow passages in the rectangular pipe. Namely, a numerical analysis and the flow visualization for the narrow passage flow which is formed by setting up some protruding parts in pipe were studied for ten numbers of models. And a study on the various effects of the height, distance, and width of a protruding part and a location of outlet was done in detail. In this investigation, a numerical calculation and the flow visualization were carried out for Reynolds numbers ranging from 1 to 700. As a result, a numerical calculation obtained was in close agreement with the flow visualization, thus the narrow passage flow with some protruding parts in rectangular pipe were clarified.