Luenberger observer for estimation of flow under disturbed conditions

Flow is one among the different process variables measured in industry. Orifice flowmeter is primary preferred due to its ruggedness and cost effectiveness. Orifice meter makes use of differential pressure transmitter to infer flow, hence change in orifice dimension, bends in pipe, density etc. have significant impact on measured differential pressure. To monitor the parametric effect, orifice meter is simulated using the Computational Fluid Dynamics (CFD) software. Transient characteristics of differential pressure is inferred from CFD for change in input, which can be further used for generation of mathematical model. The developed second order transfer function model is used in designing a Luenberger observer for disturbance rejection encountered due to variation in physical parameters of flow process, like aging of orifice, corrosion in orifice plates, variation in density, etc. The designed observer on implementation is able to track actual output with minimum error in presence of disturbance.