Abstract: We propose a modified upwind finite difference fractional step scheme for the computational fluid mechanics simulations of a three-dimensional photoelectric semiconductor detector. We obtain the optimal l2-norm error estimates by using the techniques including the calculus of variations, the energy methods, the induction hypothesis, and a priori estimates. The proposed scheme is successfully applied to the simulation of the
photoelectric semiconductor detectors.

Key words: photoelectric detector, fluid mechanics model, upwind fractional step, theoretical analysis, actual application