The process of cavitation inception and development in turbulent flow of a hydrocarbon fuel in a square channel under the action of a large constant pressure difference has been studied. It is established that the flow in this system is substantially unsteady and, despite the fact that the channel possesses both vertical and horizontal symmetry, the structure of cavitating flow is significantly asymmetric. This circumstance plays an important role in analysis of the fundamental problem of cavitation inception and development in a wide range of practical problems. The mathematical modeling of turbulent cavitating flows was based on the Navier–Stokes equations supplemented by the equation of state of a barotropic medium. Simulations were performed using a modified algorithm of the open-source computational fluid dynamics toolbox OpenFOAM. Comparison of the results of test simulations to available experimental data showed the appropriateness and efficiency of the proposed algorithm.