SYSTEMATIC INVESTIGATION OF PIPE FLOWS AND INSTALLATION EFFECTS USINGLASER-DOPPLER ANEMOMETRY .1. PROFILE MEASUREMENTS DOWNSTREAM OF SEVERAL PIPE CONFIGURATIONS AND FLOW CONDITIONERS

The first part of this paper reports on an automated facility designed to investigate the influence of disturbed flows in pipes on the shift of the error curves of gas flowmeters in situ. This facility can be e quipped with several pipe configurations (single and double bends, con vergent and divergent sections, straight pipes up to 40 diameters in l ength etc.) as well as with various types of flow conditioners. It wor ks with atmospheric air at flowrates of up to 5500 m(3)/h. A two-compo nent semiconductor Laser Doppler Anemometer (LDA) is used to measure t he spatial velocity and turbulence fields of the flow along the entire cross section in front of the flowmeter to be investigated. More than 150 velocity distributions have been determined for different pipe co nfigurations at several flowrates and data have been collected to desc ribe the corresponding flowmeter's behaviour. Some typical velocity pr ofiles for the most usual pipe elements and flow conditioners are show n. The second part of the publication, which will be presented in the following, compares the changes in the meter behaviour with the specif ic development of the flow characteristics downstream of the pipe conf igurations investigated. The model found to explain these metering eff ects will be described, evaluated and verified. (C) 1997 Elsevier Scie nce Ltd. All rights reserved.