INFLUENCE OF PIPE ROUGHNESS ON THE PERFORMANCE OF ULTRASONIC METERS FOR FLOW RATE MEASUREMENT

Ultrasonic flow meters have been recently used for flow rate measurement because they are a non-intrusive device and have the capability of making diagnostics of their performance and flow field distortion between two consecutive calibrations. The available completely developed flow velocity profiles in the literature is discussed in this paper and integrated along the meter ultrasonic path to simulate its performance. It was shown that for Reynolds number up to 1,000,000 and relatively roughness values smaller than epsilon = 0.00012 the flow is in the hydraulically smooth regime. Also, it was shown that the ratio between the area velocity and the average path velocity (k(h)) decreases close to centerline and increases close to the wall, when roughness increases.