| For t he d if f user cent rif ugal pump,t he clocking ef f ect of t he guid e vane relat ive t o t he volut e t ongue has great inf luence on hyd raulic perf orman c e,pressure pulsat ion and f low-ind uced noise of t he pump.I n t his paper,t he d if f user cent rif ugal pump wit h a specif ic speed of 112 was select ed as t he research object.Based on t he SST k-?t urbulence mod el and t he acoust i c bound ary element met hod,t he f low f ield and sound f ield of t he pump were numerically calculat ed.The d if f user cent rif ugal pump und er d if f erent f low cond it ions of clocking ef f ect was d iscussed,and t he result s provid e a ref eren c e basis f or d et ermining t he relat ive posit ion of t he rad ial guid e vanes in a cent rif ugal pump.The main research cont ent s of t his paper are as f ollows:(1)The d if f erent clocking posit ions of t he guid e vanes relat ive t o t he t ongue were charact erized by d ef ining t he clocking posit ion d imension l e s s coef f icient(C_L),and t he accuracy of f low f ield simulat ion was verif ied by experiment s.(2)By analyzing t he hyd raulic charact erist ics of t he pum p,it was f ound t hat wit h t he increase of C_L,t he head t ime-average coef f icient and t he ef f icien c y t ime-average coef f icient of t he pump bot h showed t he Gaussian d ist ribut ion law of increasing f irst and t hen d ecreasing.And t he pump's head and ef f iciency were t he largest and t he hyd raulic perf ormance was relat ively o pt imal at C_L=0.267.However,t he clocking ef f ect ha d less inf luence on t he overall d ist ribut ion of st reamline,st at ic pressure and t urbulent kinet ic energy in t he pump,and onl y changes near t he d iaphragm.These changes would cause changes in t he ext ern a l charact erist ic s of t he pump.The clocking ef f ect had a signif icant ef f ect on t he rad ial f orce and t he peak t ime of t he impeller blad es.(3)By analyzing t he charact erist i cs of pressure pulsat ion in t he f low passage of each component,it was f ound t hat t he clocking ef f ect had a great e r impact on t he clocking charact erist ic s and amplit ud e of pressure pulsat ion,and had a smaller impact on it s f requency d ist ribu t ion.And wit h t he increase of C_L,t he appearance t ime and amplit ud e change of t he"peak-valley"st ruct ure f ormed a cycle period.The clocking ef f ect has a cert ain inf luence on t he circumf eren t i a l size and d ist ribut ion of pressure in t he f low passage of e ach component.(4)By analyzing t he acoust ic charact erist ic s of t he pump,it was f ound t hat wit h t he increase of C_L,t he t ot al sound pressure level coef f icient of t he pum p also present ed t he Gaussian d ist ribut ion law of f irst increasing and t hen d ecreasing,reaching t he relat ively maximum at C_L=0.533.And t he d if f erenc e bet ween t he maximum and minimum va lue was about 3d B.Based on t he above,it was f ound t hat t he pump head and ef f iciency were relat ively highest at C_L=0.267,t he f low-ind uced noise of t he pump was at a relat ively low level.Theref ore,at C_L=0.267 can be consid ered as t he relat iv e l y opt imal clocking posit ion in t he d if f user cent rif ugal pump. |
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