A METHOD OF AND DEVICE FOR PROVIDING A CONTROL OF THE VELOCITY PROFILE OF THE WORKING MEDIUM IN THE INLET OF FLOW MACHINES

摘要

1283561 Axial and radial flow turbomachines; fluid logic switching circuits SVENSKA FLYGMOTOR A B 11 Dec 1969 60433/69 Headings F1C F1P and F1T To eliminate guide vanes at the inlet of a turbomachine the swirl in the working flow is controlled by tangential jets of fluid, in the same state as the working fluid, introduced near the rotor inlet. The machine may be a steam, gas or hydraulic turbine, a compressor or fan, or a pump and may be of axial or radial flow type. In the arrangement shown in Figs.1, 2 a supercharging compressor 1 of a diesel engine is mounted in a casing 2 having an inlet 3 with means 6 for introducing control air. The latter consists of orifices in radial tubular struts 7 which support a hollow hub 4. Some of the struts 7 communicate with the interior of hub 4 and have orifices directed in the direction of rotation of the rotor 1 so that when control air is supplied through pipe 8 a swirl in that direction is set up in the working air. The remaining struts 7 communicate with an annular manifold in the casing 2 and have orifices directed in the opposite direction so that an opposite swirl is set up when control air is supplied through pipe 9. The swirl is increased by the convergence of the casing 2. The distribution of the orifices may vary along each strut 7. The control air is tapped from the outlet of compressor 1 via a control unit 10 which may include mechanical or electrical valves or fluidic switches. Alternatively the control air may be supplied by a separate source. The control unit 10 may include a fluidic switching system, Fig. 3, comprising monostable and bi-stable devices 30, 33 respectively, a vortex device 35 to restrict flow and proportional devices 37 to 40. Control may be in response to compressor inlet or outlet pressure or rotational speed. In modifications the fluidic system includes two non-symmetric bi-stable devices, Fig. 5 (not shown) or the combination of the fluidic switch with a mechanical valve, Fig.7 (not shown). (For Figures see next page)