Accurate simulation of turbomolecular pumps with modified algorithm by 3D direct simulation Monte Carlo method

Li, Yanwu; Chen, Xuekang; Guo, Wenjin; Li, Danming; Wang, Qiangfeng; Feng, Kai

doi:10.1016/j.vacuum.2014.03.023

Cited by 10 publications

(8 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The upstream (or downstream) area and the blade area are divided into 50×10×20 and 28×10×9 cells along coordinates r, θ, and z, respectively; and the time step dt is 2.439×10 -6 s. If the pressure in a cell is less than 0.5 Pa, then the cell sizes are smaller than one-third of the mean free path, and the time step is less than 10% of the mean collision time. Repeated collisions between the same two particles in a cell are not allowed at each time step, then even if there is only 2-3 particles in a cell, the calculated results are still quite accurate [28,34]. In this work proper amount of incident simulated particles per time step will ensure that, when δ ≥ 0.1 the average particle number in a cell will be larger than 3.5 in the blade area, and be less than 2.0 only in the cells (with r ≤ 10 mm) near the axis in the downstream area.…”

Section: Dsmc Methods and Calculation Areamentioning

confidence: 95%

“…[28][29][30][31][32]. The variable hard sphere (VHS) model, the no time counter (NTC) method, and the 3D DSMC method will be used in the present simulations of turbos.…”

Section: Dsmc Methods and Calculation Areamentioning

confidence: 99%

“…The detailed content is indicated in Ref. [28]. When implementing the calculation process of collisions between particles, the gas is assumed as N 2 .…”

Section: Dsmc Methods and Calculation Areamentioning

confidence: 99%

See 2 more Smart Citations

Design and analysis of vacuum air-intake device used in air-breathing electric propulsion

Li¹,

Chen²,

Li³

et al. 2015

Vacuum

Self Cite

View full text Add to dashboard Cite

Section: Dsmc Methods and Calculation Areamentioning

confidence: 95%

“…[28][29][30][31][32]. The variable hard sphere (VHS) model, the no time counter (NTC) method, and the 3D DSMC method will be used in the present simulations of turbos.…”

Section: Dsmc Methods and Calculation Areamentioning

confidence: 99%

See 1 more Smart Citation

Design and analysis of vacuum air-intake device used in air-breathing electric propulsion

Li¹,

Chen²,

Li³

et al. 2015

Vacuum

Self Cite

View full text Add to dashboard Cite

“…Previously, others have used DSMC to simulate a TMP in 2D [2][3][4][5] and in 3D [6][7][8][9]. While a 2D approach has the advantage of short computing times, the simplified geometry drastically reduces the sensitivity of the simulation to changes in the real geometry and the boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

Simulation of a complete triple turbo molecular pumping stage using direct simulation Monte Carlo in 3D

Rose¹

2014

AIP Conference Proceedings

View full text Add to dashboard Cite

A triple stage turbo molecular pump is simulated using the DSMC method in 3D. A 90° sector of the complete pump is simulated taking the symmetry of the pump into account. Simulations were performed for various fore line pressures in order to determine the compression ratio and the maximum pumping speed. Various features of the three dimensional flow field are discussed. Also the CPU time required to obtain the flow field is discussed. The simulations presented here are a powerful tool for the design and improvement of turbo molecular pumps.

show abstract

“…They predicted the compression ratio and speed factor of a single-stage TMP according to two dimensional (2D) models. With the widespread application of Monte Carlo methods, Chang and Jou (2001), Wang et al (2009) and Li et al (2014) used the three dimensional (3D) models to analysis the pumping performance of TMP by direct simulation Monte Carlo method. However, these traditional researches only calculated the performance parameters of a single-stage TMP by building a simple blade row model.…”

mentioning

confidence: 99%

A New Modeling Method to Reveal Pumping Mechanism of Turbomolecular Pump

2021

JAFM

View full text Add to dashboard Cite

In order to meet the calculating requirements of high speed and miniaturized turbomolecular pump (TMP), a new modeling method is proposed for a rotor-stator row. In the same Cartesian coordinate system, the analytical equations of blade row are derived according to the real three-dimensional geometric model. A self-defining procedure is written to simulate the flow of gas molecules in TMP based on test particle Monte Carlo method. The procedure not only can calculate transmission probability of rotor row, stator row and a rotor-stator row but also evaluate the pumping performance of different blade parameters. The simulation results and known experimental data have a good agreement to confirm the feasibility of presented modeling method. The flow analysis shows that molecules at outlet of rotor row tend to accumulate in large radius and this phenomenon is obvious for high rotational speed. The differences were found between a single-stage row and a rotor-stator row. In rotor row, the molecular density at the rear blades is the highest. This is beneficial for pumping speed of TMP because 57% of molecules at the rear blades are likely to reach outlet. This will provide a direction for the structural optimization design of the blades in the future. In stator row, the molecular density reaching outlet does not significantly increase with the increase of blade velocity ratio, which indicates that the stator row is mainly used to increase the pressure ratio of TMP. The analysis of molecular density in each region reveals the pumping mechanism of TMP.

show abstract

Accurate simulation of turbomolecular pumps with modified algorithm by 3D direct simulation Monte Carlo method

Cited by 10 publications

References 27 publications

Design and analysis of vacuum air-intake device used in air-breathing electric propulsion

Design and analysis of vacuum air-intake device used in air-breathing electric propulsion

Simulation of a complete triple turbo molecular pumping stage using direct simulation Monte Carlo in 3D

A New Modeling Method to Reveal Pumping Mechanism of Turbomolecular Pump

Contact Info

Product

Resources

About