Research On Characteristics And Numerical Simulation Of Flow Field Of The Anomalous Orifice Spool Valve

Hydraulic spool valve is one of the most widely used infrastructure control component in the hydraulic transmission and control technology. As hydraulic tech is widely used in many fields, it is difficult for traditional single form spool valve to show a satisfactory control performance in many kinds of hydraulic system. In recent years, many anomalous orifices are used as spool valve orifice because of some of its characteristics, such as bigger hydraulic radius, good antiblocking performance, easily controllable area grads and excellent flow trimmability. However, compared with traditional cylindrical spool valve, most anomalous orifices still face some problems, for instance, existing research data or achievements are less, study on characteristics lack depth or are incomplete. That brings some difficulties to the design and the improvement of performance of anomalous orifice spool valve.In this paper, a kind of slope type circular opening and non-circular opening anomalous orifice spool valve which is widely used in engineering machinery is took as the research object, systematically study and analyze on characteristics such as flow field, steady flow force and flow coefficient of anomalous orifice spool valve are conducted by combining theoretical analysis, flow field simulation and partly experimental verification. Firstly, MATLAB software is used to do a function resolution on flow area of the anomalous orifice spool valve, and numerical simulation on velocity and pressure distribution in the valve cartridge under different inlet flows and opening are done and the results are analyzed. Secondly, Steady flow force under different inlet flows and opening conditions are calculated and analyzed, which is based on momentum theory and CFD numerical integration methods. At last, flow coefficients of anomalous orifice spool valve are calculated by CFD technology and relations between flow coefficients and flow or opening are discussed, then, flow coefficients which are calculated under some differential pressure are verified by experiment.By doing the work in above aspects, the influence of flow and opening on characteristics such as flow field, steady flow force and flow coefficient of anomalous orifice spool valve are generalized, and that will provide some theoretical guidance for optimizing the valve cartridge structure, exact matching design of spool drive system, flow accurately control and the research on energy-saving and noise-reducing of hydraulic valve. Moreover, it also provides new ideas for accurate calculation of the steady flow force, flow coefficient and performance prediction of hydraulic valves in a low-cost and short cycle condition.