- Abstract. Analitycal model for predicting the size of the Mach reflection wave configuration in steady flows has been improved (Azevedo 1989; Azevedo and Liu (1993)). Predictions based on the modified analytical model were compared to available experimental results. The agreement was found to be better than that obtained by Azevedo (1989) and Azevedo and Liu (1993). The reason for the better agreement is due to the fact that, unlike Azevedo's original model, downstream effects were not neglected in the modified model which was developed in the course of this study.