Passage of a Turbulent Stream Through Honeycomb of Large Length-to-Diameter Ratio

Abstract

An analysis is performed, similar to the classical one for screens, of the effect of a honeycomb on a turbulent stream, when the cell length is large enough to permit the flow to become fully developed. The results indicate that a honeycomb should reduce the turbulence level of a stream passing through it more effectively than a screen, due to two effects: (a) The annihilation of the transverse fluctuation, dependent on the assumption of fully developed flow; (b) the effect of the mass of fluid in each cell, which must be accelerated to permit the passage of a fluctuation. The latter suggests that the honeycomb may be viewed as an inductive filter, if the screen is regarded as the fluid mechanical analogy of a resistive one. A small number of measurements in water are presented which lend quantitative support to the argument. Finally, design charts are presented, which permit calculation of the reduction to be expected from the placing of a given honeycomb in a given flow.