scholarly journals Study of interstage channel of hybrid turbomolecular pump

2021 ◽  
Vol 5 (1) ◽  
pp. 9-17
Author(s):  
J. A. Shostak ◽  
◽  
N. K. Nikulin ◽  
P. A. Shostak ◽  
G. T. Tsakadze ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Statistical Modeling ◽  
Test Particle ◽  
Flow Passage ◽  
Turbomolecular Pump ◽  
Gas Molecules ◽  
Pass Through

The calculation is based on the use of Monte Carlo method (method of test particle), which consists in the statistical modeling of processes. The article describes an algorithm to construct a mathematical model step by step. The article defines both a probability for gas molecules to pass through the interstage channel of a hybrid turbomolecular pump in forward and backward direction. The effect of the movable walls limiting the channel is taken into account. Results and, accordingly, recommendations, given in the article, can be used in designing a flow passage of the hybrid turbomolecular pumps. The dependencies of a probability for gas molecules to pass through the interstage canal on the relative parameters determining the geometry and dynamics of the channel walls are given

scholarly journals Simulation of BHA sticking elimination effectiveness using jarring devices

2018 ◽  
pp. 64-71
Author(s):  
V. M. Charkovskyi ◽  
M. М. Slepko
Keyword(s):  
Mathematical Model ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Queuing Theory ◽  
Strength Properties ◽  
Laboratory Research ◽  
Rock Destruction ◽  
The Law ◽  
Device Use ◽  
Restraining Force

A stochastic mathematical model of the jarring device use effectiveness for releasing the stuck BHA was studied based on Monte-Carlo method of probability of the corresponding result. Distribution histograms were designed and the law of sticking force distributionp in various cases was defined. The conditions, when the probability of growth of the restraining force is unacceptably high were defined. The time of jarring and the number of impacts for probable tool release were defined using queuing theory elements. The results of laboratory research of strength properties of some Precarpathian rocks were given and approach for their accounting as criteria of rock destruction during jarring were proposed.

SIMULATION OF GAS RELEASE FLOWS FROM THE FLOW SURFACES OF TURBOMOLECULAR VACUUM PUMPS

2020 ◽  
pp. 45-48
Author(s):  
M. V. Fomin ◽  
I. M. Fomina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Gas Flow ◽  
Three Dimensional ◽  
Low Density ◽  
Gas Release ◽  
The Monte Carlo Method ◽  
Turbomolecular Pump ◽  
Flow Part

An algorithm for modeling and an example of calculating gas release flows from the surfaces of the flow part of a turbomolecular pump by the Monte Carlo method in a three-dimensional setting low-density gas flow is considered.

scholarly journals Analysis of density distribution of gas molecules effused in vacuum vessel by Monte Carlo method.

Shinku ◽  
1986 ◽  
Vol 29 (5) ◽  
pp. 310-314
Author(s):  
Kazuyuki NAKAMURA ◽  
Kenjiro OBARA ◽  
Yoshio MURAKAMI
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Density Distribution ◽  
Vacuum Vessel ◽  
Gas Molecules

Analysis of Precision Reliability for CX Series of Five-Axis Turning-Milling Center

2011 ◽  
Vol 383-390 ◽  
pp. 4775-4782
Author(s):  
Jian She Gao ◽  
Wei Wei Yang ◽  
De Ping Liu ◽  
Yu Ping Wang ◽  
An Qing Zhang
Keyword(s):  
Mathematical Model ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Analytical Method ◽  
Military Industry ◽  
Machining Center ◽  
Nc Machine ◽  
Five Axis ◽  
The Mathematical Model

Five-axis turning-milling center is an important and advanced NC machine in fields of military industry, aerospace, automobile and medical machinery. The kinematics equation is built based on D-H method by the analysis of the structure of five-axis turning-milling center. The precision workspace is presented and its definition is given. The precision workspace of five-axis turning-milling center is analyzed based on Monte Carlo method. The mathematical model of precision reliability for machining center is built. The sensitivity of precision reliability for machining center is analyzed using analytical method. Finally, sensitivity histograms are given.

scholarly journals Direct Statistical Modeling of Spread of Epidemic Based On a Stage-Dependent Stochastic Model

2021 ◽  
Vol 16 (2) ◽  
pp. 169-200
Author(s):  
K. Loginov ◽  
N. Pertsev
Keyword(s):  
Infectious Disease ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Stochastic Model ◽  
Statistical Modeling ◽  
Numerical Study ◽  
The Monte Carlo Method ◽  
Parametric Description ◽  
Dependent Model ◽  
Time Of Admission

A stochastic stage-dependent model of spread of an epidemic in a certain region is presented. The model is written in the form of a continuous-discrete random process that takes into account the passage of individuals through various stages of an infectious disease. Within the framework of the model, the population of the region is represented in the form of cohorts of individuals, structured according to immunological, clinical, epidemiological and demographic criteria. All cohorts make up two blocks. Individuals belonging to the cohorts of the first block are considered indistinguishable within a fixed cohort and have the same type of parametric description. Individuals belonging to the cohorts of the second block differ from each other by the time of admission to a particular cohort and by the time of stay in this cohort. An algorithm for statistical modeling of the dynamics of cohorts of individuals based on the Monte Carlo method is developed. A numerical study of the dynamics of cohorts of individuals was conducted for sets of parameters reflecting different variants of transmission of infection between individuals.

Numerical simulation of gas flow through the flow part of a multi-stage turbomolecular vacuum pump

2020 ◽  
pp. 76-78 ◽  
Author(s):  
M.V. Fomin ◽  
O.R. Chernyishev
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Gas Flow ◽  
Pressure Ratio ◽  
Vacuum Pump ◽  
Maximum Pressure ◽  
Pump Impeller ◽  
Multi Stage ◽  
Turbomolecular Pump ◽  
Flow Through

The modeling of gas flow through a multi-stage flowing part of a turbomolecular vacuum pump to optimize the parameters of rotor and stator impeller wheels is considered. The developed program of statistical modeling by the Monte Carlo method allows us to determine the influence of the geometric parameters of the stages on the pump performance indicators. Keywords turbomolecular pump, impeller wheels, maximum action speed, maximum pressure ratio, Monte Carlo method. [email protected]

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