The aim of the present study was to investigate the sensitivity of a multiphase Eulerian CFD model with respect to relations defining drag forces between phases. The mean relative error as well as standard deviation of experimental and computed values of pressure gradient and average liquid holdup were used as validation criteria of the model. Comparative basis for simulations was our own data-base obtained in experiments carried out in a TBR operating at a co-current downward gas and liquid flow. Estimated errors showed that the classical equations of Attou et al. (1999) defining the friction factors Fjk approximate experimental values of hydrodynamic parameters with the best agreement. Taking this into account one can recommend to apply chosen equations in the momentum balances of TBR.

The mathematical approach to SOFC modelling helps to reduce dependence on the experimental approach. In the current study, six different diffusion mass transfer models were compared to more accurately predict the process behavior of fuel and product diffusion for SOFC anode. The prediction accuracy of the models was extensively studied over a range of parameters. New models were included as compared to previous studies. The Knudsen diffusion phenomenon was considered in all the models. The stoichiometric flux ratio approach was used. All the models were validated against experimental data for a binary (CO-CO2) and a ternary fuel system (H2-15 H2O-Ar). For ternary system, the pressure gradient is important for pore radius below 0.6 μm and current density above 0.5 A/cm2. For binary system, the pressure gradient may be ignored. The analysis indicates that the MBFM is identified to be the best performing and versatile model under critical SOFC operating conditions such as fuel composition and cell temperature. The diffusive slip phenomenon included in MBFM is useful in SOFC operating conditions when fuel contains heavy molecules. The DGMFM is a good approximation of DGM for the binary system.