In non-ideal flow field measurement conditions

electromagnetic flow sensor with locally shrunk measurement pipe will have a big measurement error. Increasing the uniformity of weight function distribution of sensor helps to improve its non-ideal flow field measurement performance. Therefore

it is necessary to carry out research on the distribution law of weight function of sensor. Based on the finite element software COMSOL

firstly

analyze the uniformity of weight function of electromagnetic flow sensors with four different locally shrunk measurement pipe. Results show that weight function of sensor with rectangular section is the most uniform. Then

a three-dimension model for electromagnetic flow sensor with rectangular shrunk measurement pipe is established.And the distribution law of weight function with length

width

and height of the rectangular segment is studied.Results show that

the height of rectangular segment has the greatest effect on the uniformity of the weight function

the width has a slightly smaller effect

and the length has the smallest effect. The smaller the height and width of the rectangular segment are

the more uniform the weight function distribution is

and the smaller the influence of the non-ideal flow field on the measurement result is.