Analysis Of Flow Field Characteristic Of Orifice And Study On Damping Grooves In Hydraulic Pump Valve Plate

Orifices are used widely in hydraulic technology.Characteristics of orifices flow field have great influence on performance of hydraulic components and systems.So it is important to study it.But why the flow rate easy to pulsate at small opening of orifice,and how about the damping groove angle influent the hydraulic pump performance,the study is rare.The paper used Pro/E to eastablishes the different angle and opening of the triangle-notch orifice three-dimensional models,used Gambit to mesh grids,boundary conditions is pressure-inlet and pressure-outlet,viscous model choosed laminar or SST k-omega(2 eqn) according to different△p,and uses FLUENT software to simulate the flow field of the models at different pressure drop△p.We got the data of flow rate and the lowest pressure in flow field at different pressure drop.Used Matlab to draw the flow rate-△p curves,and analysing the data of the lowest pressure from the simulation results,we get the relations among the flow rate change, angle,opening and△p,and the lowest pressure in flow field:when reducing opening and angle,the flow rate reduce greatly;when reducing opening and angle,the lowest pressure will increase,it is difficult to cavitate.So compared with wide-angle orifice,small-angle orifice have nature of small flow rate changes and difficult to cavitate.The drawing flow rate-△p curves accord with theory flow rate-△p curves,pressure distribution in gap and IPH internal gear pump using small angle damping groove verify the correctness of results.In the final using the results to guide the design of damping grooves of hydraulic pump valve plate.The main innovation of the paper is the past we believed when pressure ratio before and after orifice＞3.5,Cavitation will occur.From the results we know it is subject to a certain orifice structure(angle and height).In small-angle or small height orifices,cavitation cannot occur even at very high pressure ratio of 300 or high△p of 30MPa.The results let us have a deeply understanding flow field characteristics of orifice and rigidity of orifice,deeply understand the relations among△p,angle,opening,and flow rate changes,and the lowest pressure in flow field,so it has great values to design anti-cavitation orifice structure and hydraulic components orifices or damping grooves.