Three-Dimensional Flow Analysis for Estimation of Measuring Error oi Orifice Flowmeter due to Swirling Flow

선회로 인한 오리피스 유량계의 계량오차 예측을 위한 삼차원 유동해석

Three-dimensional pipe flows with elbows and tees for few different pipe fittings are calculated to estimate the effect of swirling flow on measuring accuracy of orifice flow meter. It is evaluated how the pressure difference across the orifice is dependent on the length of upstream straight pipe in a branch and how swirl intensity, swirl angel and axial velocity distribution affect the measuring error of orifice flowmeter. From the results, it is found that, regardless of flow rate specified in this calculation, the effect of the straight pipe length can be neglected for the lengths larger than thirty diameters although there still remain significant swirl at the orifice