Flow rate measurements in turbulent pipe flows with minimal loss of pressure using a defect-law

In the paper, a simple and very accurate measurement technique is presented to determine the volumetric or mass flow rate. It is based on the fully-de veloped turbulent pipe flow, a new analytical universal velocity-profile ov er the entire pipe section and a single-point measurement. In combination w ith an optimized straightener this technique has to show minimal pressure l oss, very moderate costs and high measuring accuracy compared to LDA-measur ements. It is possible to apply the measuring prinicple to nonisothermal ga s flows, too. (C) 2001 Elsevier Science Ltd. All rights reserved.