Numerical simulation of interaction between internal solitary waves and submerged ridges

•Detailed interaction types (weak, moderate and strong) are observed and analysed.•A modified degree of blocking Bm including nonlinear effect is proposed.•Maximum energy loss for ISW–ridge interaction can be as high as 35%.•Important parameters have self-similar characteristics when described by Bm.•Empirical equations are proposed to predict key hydrodynamic variations.