The superior accuracy of the arc electrode magnetic flowmeter is demonstrated by optimizing its weight function and comparing its performance downstream of a 90 elbow and gate valve (50% open) with that of an optimized multipoint (six-electrode) and single-point electrode flowmeter. Research literature is inconclusive on the necessary angle of arc electrode magnetic flowmeters, as well as the required spacing for multipoint flowmeters to optimize meter accuracy. This article determines the optimum configurations for both arc and multipoint flowmeters using the coefficient of variation of the weight function as the basis for optimization. This study illustrates that the accuracy of multipoint electrode flowmeters exhibits the same oscillatory behavior of single-point flowmeters, but the magnitude of the deviation is greatly reduced. The numerical study also provides supporting evidence that the optimized arc electrode flowmeter is superior to the optimized multipoint and single-point electrode flowmeters.

Energy losses occurring in pipe junctions have been studied for many years. Head loss coefficients ͑K͒ are commonly used to characterize losses across elbows, tees, crosses, valves, and other pipe fittings. When accurate values of K are used, the flow rate and corresponding total head at any location in a pipe network can be calculated. While K is well defined for most pipe junctions and fittings, the literature has limited documentations of K for crosses. This study was commissioned to determine K for a wide range of flow combinations in a pipe cross with equal diameter pipes and varied flow combinations. This study provides and innovatively presents over 1,000 experimental values of K for designing and analyzing equal diameter pipe crosses.

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Pope et al. | http://dx.