Study on the influence of the splitter blade length on radial and axial force of a centrifugal pump

Ma, Qijiang (author), Liu, Zhenbo (author), Jiang, Sen (author)

To enhance the operational stability of centrifugal pumps, this study investigates the influence of splitter blade length on the axial and radial forces of centrifugal pumps. Using the SST k-ω turbulence model and experimental research, the external characteristics, axial force, radial force, and time-frequency characteristics of pressure pulsation were compared among impellers without splitter blades and those with splitter blades of two different lengths. The results show that impellers with a conventional structure achieve higher efficiency near the design operating point. However, under low-flow conditions, the rectifying effect of splitter blades allows impellers with splitter blades to achieve higher efficiency. For impellers with splitter blades, the axial force shows a periodic behavior, presenting two peak values — one large and one small — within each cycle. The addition of splitter blades shifts the radial force acting on the impeller to one side, requiring an increase in the support strength and stiffness of the rotor system. Furthermore, splitter blades influence the pressure pulsation at the impeller's inlet and outlet, the original impeller has an additional pulsation energy at 145 Hz but the splitter blades are different. Thus, an impeller with splitter blades can reduce the frequency pulsation and optimizing flow conditions. This study provides valuable theoretical insights and data support for the hydraulic structural optimization of centrifugal pumps.

• Language: English
• Keywords: centrifugal pump, axial force, radial force, splitter blade length, pressure fluctuation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 12 str.
• Numbering: Vol. 71, no. 5/6
• PID: 20.500.12556/RUL-174436
• UDC: 621
• ISSN on article: 2536-3948
• DOI: 10.5545/sv-jme.2024.1259
• COBISS.SI-ID: 251426307
• Publication date in RUL: 02.10.2025

Record is a part of a journal

• Title: Strojniški vestnik
• Shortened title: Stroj. vestn.
• Publisher: Fakulteta za strojništvo
• ISSN: 2536-3948
• COBISS.SI-ID: 294943232

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian

Abstract

Za izboljšanje obratovalne stabilnosti centrifugalnih črpalk ta študija preučuje vpliv dolžine vmesnih lopatic na aksialne in radialne sile v centrifugalnih črpalkah. S pomočjo SST k-ω turbulenčnega modela in eksperimentalne analize smo primerjali karakteristiko, aksialno silo, radialno silo ter časovno-frekvenčne značilnosti pulziranja tlaka med rotorji brez vmesnih lopatic in rotorji z vmesnimi lopaticami dveh različnih dolžin. Rezultati kažejo, da prvotni rotorji dosegajo višjo učinkovitost v bližini točke največjega izkoristka. Vendar pa pod pogoji nizkega pretoka usmerjanje toka z vmesnimi lopaticami omogoča, da rotorji z vmesnimi lopaticami dosegajo višji izkoristek. Pri rotorjih z vmesnimi lopaticami aksialna sila kaže periodičnost z dvema vrhovoma – enim večjim in enim manjšim – znotraj vsakega cikla. Dodatek vmesnih lopatic povzroči spremembo radialne sile na rotor, kar zahteva povečanje nosilnosti in togosti rotorskega sistema. Poleg tega vmesne lopatice vplivajo na tlačne pulzacije na vstopu in izstopu iz rotorja; prvotni rotor izkazuje tlačne pulzacije pri frekvenci 145 Hz, kar pa je pri rotorjih z vmesnimi lopaticami drugače. Tako lahko rotorji z vmesnimi lopaticami zmanjšajo frekvenčne pulzacije in izboljšajo pretočne pogoje. Študija daje pomemben teoretični vpogled in podatkovno podporo za hidravlično konstrukcijsko optimizacijo centrifugalnih črpalk.

• Keywords: centrifugalna črpalka, aksialna sila, radialna sila, dolžina vmesnih lopatic, tlačne pulzacije