ANFIS-based model for predicting actual shear rate associated with wall slip phenomenon

Wall slip can be defined as a phenomenon in the flow of suspensions due to the movement of particles away from the wall boundary, leaving a thin liquid rich layer adjacent to the wall. It should be taken into consideration in material designing, manufacturing and transportation as it may cause inaccurate rheological measurements such as shear rate and viscosity. The apparent (measured) shear rate is higher than the actual shear rate. The traditional method for actual shear rate determination is not efficient from the perspective of time and cost consumption. Therefore, there is a need to develop a mathematical model that is able to detect the complex pattern of the actual shear rate and accurately predict its value based on the available measured input variables. Volumetric concentration, particle size, temperature and shear stress are selected as the input, while the actual shear rate is kept as output while designing the architecture of ANFIS model. Sixteen ANFIS models with different architecture were designed and evaluated using different statistical indices. Model XVI with number of membership function equal to 3, input product of two sigmoid membership function, output linear membership function type integrated with hybrid optimization method appears to be the most suitable model architecture for predicting the actual shear rate.