Model calibration and validation techniques

Calibration and validation are two important aspects of any computational work that involves assumptions and numerical solution. Calibration involves the specification of boundary conditions required in the CFD models. Validation is the last step to be performed and is vital to confirming that the results represent a reasonable solution from both conceptual and numerical perspectives. The following section summarises the current experimental techniques for MBR CFD model calibration and validation. 

A more feasible method for velocity measurement involves the use of an electromagnetic current meter. Brannock (2003) measured the three-dimensional liquid velocities at different positions within an anoxic reactor using an electromagnetic current meter, which is not affected by the physical properties of the fluid or the presence of bubbles and solids. 

A rotational rheometer has been commonly used to measure the rheology of activated sludge (Rosenberger et al, 2002 Rios et aL, 2007a Brannock et al, 2010b). Rheograms can then be developed based on the measurement 

NMR imaging allows the monitoring of the composition of a sample by measuring the distribution of mobile protons in any slice of the specimen (Buetehom et al, 2011). The microfiltration process (permeate flow and cake growth) of model solutions (water or silica suspensions) has been visualised using NMR imaging (Buetehom et al, 2011). 

10 Comparison of the logarithmic scale of pressure drop obtained from experimental calibration and empirical correlations for tube banks. 

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