Flow patterns around the flat plates in a turbulence promoter. 3rd Report, Coefficient of loss in the case of multiple flat plates set on the lower wall of the flow passage.

Abstract

In the 1st report, a theoretical and experimental analysis of flow patterns occurring around a single flat plate set on the lower wall of the flow passage, as the simplest type of turbulence promoter, was described. In the 2nd report, an experimental analysis of the case of a single flat plate set on the upper wall of the flow passage was described. This 3rd report describes an experimental analysis of the case of many flat plates set on the lower wall of the flow passage. The relationships between the coefficient of loss ζ and the Reynolds number Re, the number of plates N, the pitch of plates P are examined. A new nondimensional number S is proposed as a measure of the effect of the duct wall and the arrangement of many flat plates, and how the coefficient of loss ζ, can be expressed as a function of the number S is explained. These experimental results are very useful not only for the design of turbulence promoters but also for the design of heat exchangers.