Engineering Method for Calculating the Parameters of an Annular Jet with a Vacuum Air Cavity Beneath It

In designing mine spillways without a profiled water drain surface that operates in the absence of contact of the water jet with the concrete within a funnel and transitional section, the problem arises of calculating the trajectory of an annular jet, taking into account the vacuum in the space under the jet. A hydraulic method for such calculation using a virtual jet is described. Calculated dependences are given. The results of calculations are compared to test results, confirming the operability of the proposed method.