of the flow axis such orientation is in contrast to the upward or downward displacement which the nozzle centerline axes make with the flow axis for the vertical columns on either side thereof since the section is taken through the center of each nozzle element at the exhaust plane 14 the section line does not pass through the throat region 24 of any nozzle each nozzle is fed from a common manifold 42 fig1 shows an alternate structure to the essentially conical supersonic nozzle element discussed above the nozzle plate 16 is configured to include rectilinear nozzles 46 which are essentially rectangular in cross section this and other configurations are readily substitutable for the round nozzle elements from a mixing performance consideration fig1 is a conceptual sketch which attempts to visualize the direction of flow of the working fluid from a group of several cooperating nozzle elements and the entwinement of the effluent from each nozzle element as it passes downstream advancing along the flow axis 26 the downstream surface 18 of the nozzle plate 16 is drawn in perspective and a typical pattern of nonaxial components 32 of velocity of the working fluid is indicated each in its own exhaust plane 14 the nozzle array shown is consistent with that described in.