Fluid analysis of cylindrical and screw type Roots vacuum pumps

Hsieh, Chíu-Fan; Zhou, Qin-Jie

doi:10.1016/j.vacuum.2015.04.037

Cited by 37 publications

(14 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results of computational fluid dynamics (CFD) modelling of Roots vacuum pumps with cylindrical and screw types rotors are presented in [5]. For mesh creating and working process modelling PumpLinx software was used.…”

Section: Summary 1 Introductionmentioning

confidence: 99%

Working process of Roots vacuum pumps

Raykov¹,

Бурмистров²,

Salikeev³

et al. 2021

Vak Forsch Prax

View full text Add to dashboard Cite

Zusammenfassung Entwicklung und Verifizierung des CFD‐Modells für Wälzkolbenpumpen Wälzkolbenpumpen sind aufgrund der Ölfreiheit des Arbeitsvolumens, der Einfachheit der Konstruktion, des hohen Arbeitsdurchsatzes und der Zuverlässigkeit weit verbreitet. Der Arbeitsprozess in Roots‐Gebläsen wurde mit Hilfe von Methoden der numerischen Strömungsmechanik (CFD) untersucht. Es wurde ein hexaedrisch strukturiertes Netz des Arbeitsvolumens mit konstanter Schrittweite über den Rotordrehwinkel erstellt. Luft wurde als Arbeitsmedium im Modell eines kompressiblen idealen Gases betrachtet. Für die Berechnung wurde das Turbulenzmodell Shear Stress Transport (SST) verwendet. Die Verifizierung des entwickelten mathematischen Modells wurde durch den Vergleich der berechneten und experimentell gewonnenen Beziehung zwischen der Fördermenge und dem Druckverhältnis bei verschiedenen Drehzahlen im Kompressorregime durchgeführt. Der Unterschied zwischen Berechnung und Experiment übersteigt nicht 8 %. Es wurde ein Vergleich zwischen berechneten und experimentellen Indikatordiagrammen in der Arbeitskammer durchgeführt und das Wälzkolben‐Vakuumpumpumpen‐Drehzahlniveau gemessen. Die maximale Differenz zwischen dem Experiment und der Berechnung mit der CFD‐Methode beträgt 9,8 %. In beiden Fällen kann der Unterschied zwischen Berechnung und Experiment vor allem durch Fehler bei der Messung der tatsächlichen Radialabstände erklärt werden. Die Analyse der Geschwindigkeitsfelder im Roots‐Gebläse, das im Vakuum‐ und Kompressorregime arbeitet, wurde mit Hilfe des CFD‐Modells durchgeführt. Die Gasgeschwindigkeit im Spalt ist bei niedrigen Drücken viel höher. Dies lässt sich durch die größere Druckdifferenz zwischen Einlass und Auslass bei Vakuumbedingungen erklären.

show abstract

Section: Summary 1 Introductionmentioning

confidence: 99%

Working process of Roots vacuum pumps

Raykov¹,

Бурмистров²,

Salikeev³

et al. 2021

Vak Forsch Prax

View full text Add to dashboard Cite

show abstract

“…The Taguchi method is implemented for obtaining the flow rate [1]. For improving the pump performance, a new generation method of line locus is proposed and verified its performance, analyzed the performance difference of cylinder blade and screw blade, put forward the design scheme of multistage series parallel and phase change angle to improve the performance of multistage roots vacuum pump [2][3][4]. The design of variable Technical Editor: Jader Barbosa Jr., Ph.D.…”

Section: Introductionmentioning

confidence: 99%

Numerical research on viscous oil flow characteristics inside the rotor cavity of rotary lobe pump

Guo

2019

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

In order to reveal the influence of medium viscosity on flow characteristics in rotary lobe pump, the flow of five media with different viscosities, ranging from 1 (cst) to 110 (cst) has been studied in this paper. Based on the dynamic mesh model and the deformation technology of local grid reconstruction, the effects of viscosity, gap structure and speed on flow rate and pressure were investigated by transient numerical simulation, which were also verified by experiments. The results show that the viscosity has a significant influence on the performance of rotary lobe pump. With the increase in viscosity, the flow of fluid in rotor cavity tends to be steady. And the viscosity force could hinder the leakage flow of the medium in rotor cavity to some extent. The change in viscosity of the fluid medium would affect its outlet flow rate, and the outlet flow rate of 110 (cst) medium is 40% higher than that of the 1 (cst) medium. As the rotational speed is reduced from 400 (r/min) to 100 (r/ min), the outlet flow rate decreases by 95% at 11 (cst) and by 80% at 72 (cst). Additionally, compared with the fixed gap structure, the gradient gap structure can effectively optimize the flow pulsation in the low-viscosity fluid, which reduces the pressure fluctuation by more than 30%.

show abstract

“…The paper concludes that the difference between both models decrease as the compressor operating speed increases. Hsieh [13] compared the 3D numerical results of cylindrical and screw type roots vacuum pumps using the CFD solver PumpLinx™ [14] assuming atmospheric inlet pressure. The results show that the cylindrical type pump has higher efficiency, while the screw type pump has a lower fluctuation in mass flow rate.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Customised Mesh for Twin Screw Vacuum Pumps

Kovačević

Read

et al. 2019

Designs

View full text Add to dashboard Cite

The market for dry vacuum pumps is expected to increase in the coming years. Improving the efficiency of these machines requires comprehensive understanding of the flow dynamics within the working chambers. For this purpose, Computational Fluid Dynamics (CFD) is used as it offers better insight of the working process of a screw machine. In this study, a twin-screw vacuum pump with a large helix angle was analysed. This is a challenging case for CFD due to the limitations of grid generation in the transverse plane on the mesh quality. Two types of transverse meshes were generated using the software SCORGTM: casing to rotor non-conformal mesh and casing to rotor conformal mesh. The quality of the mesh in terms of aspect ratio and orthogonality were compared. The casing to rotor conformal mesh was used with ANSYS Fluent in order to obtain performance characteristics of the vacuum pump with the moderate helix angle of 62° such as the mass flow rate, rotor torque, and indicated power. The performance prediction results were satisfactory but the grid quality was relatively low with orthogonality reaching 40° and aspect ratio over 250 in some cases. As the helix angle increases the quality of mesh decreases. This paper presents the new development of a grid generation algorithm which uses the normal rack to map the fluid domain in the normal plane instead of the transverse plane. This new mesh generation method is expected to better align the computational grid with the main and leakage flows in order to significantly improve grid quality and reduce the numerical diffusion in case of screw machines with large helix angles.

show abstract

Fluid analysis of cylindrical and screw type Roots vacuum pumps

Cited by 37 publications

References 23 publications

Working process of Roots vacuum pumps

Working process of Roots vacuum pumps

Numerical research on viscous oil flow characteristics inside the rotor cavity of rotary lobe pump

Numerical Study of Customised Mesh for Twin Screw Vacuum Pumps

Contact Info

Product

Resources

About