FLOW DEVELOPMENT DOWNSTREAM OF A STANDARD TUBE BUNDLE AND 3 DIFFERENTPOROUS PLATE FLOW CONDITIONERS

The development of the mean velocity and turbulence intensity downstre am of a standard tube bundle and three different slotted plates has be en measured in a four inch pipe using a 1-D laser Doppler anemometer s ystem. The results show how far the standard tube bundle must be place d upstream of the orifice plate to obtain fully developed mean velocit y and turbulence. Numerical analyses of how shaping the velocity profi le exiting a flow conditioner effects the development of both the turb ulence and mean velocity have been performed. These analyses indicate that a power law profile (1/7th) with a 9% turbulence intensity produc es a fully developed flow in the shortest pipe length, 20 D. A parabol ic profile requires a slightly longer development length. A uniform fl ow required the longest length of pipe. The effect of the turbulence i ntensity produced by the flow conditioner was also investigated. Three different slotted plates were manufactured to produce a 1/7th power l aw, parabolic, and uniform velocity profile downstream of the plate. T he development of the mean velocity and turbulence have been measured. These data were compared to the predictions with very favorable resul ts. The simulations accurately represented the flow field and turbulen ce intensity distributions. (C) 1998 Elsevier Science Ltd.