分子流模块

模拟真空系统中低压气体流动的软件

分子流模块

在离子注入器中,沿离子束的分子平均数密度用作评估设计的品质参数。它必须通过硅片绕轴旋转角度的函数的形式计算。

Understanding and Predicting Free Molecular Flows

Vacuum engineers and scientists use the Molecular Flow Module to design vacuum systems and to understand and predict low-pressure gas flows. The use of simulation tools in the design cycle has become more widespread as these tools improve understanding, reduce prototyping costs, and speed up development. Vacuum systems are usually expensive to prototype. Therefore, an increased use of simulation in the design process can result in substantial cost savings. The gas flows that occur inside vacuum systems are described by different physics than conventional fluid flow problems. At low pressures, the mean free path of the gas molecules becomes comparable to the size of the system and gas rarefaction becomes important. Flow regimes are categorized quantitatively via the Knudsen number (Kn), which represents the ratio of the molecular mean free path to the flow geometry size for gases:

流体类型 Knudsen 数
连续流 Kn < 0.01
滑动流 0.01 < Kn < 0.1
过渡流 0.1 < Kn < 10
自由分子流 Kn > 10

While the Microfluidics Module is used for modeling slip and continuum flows, the Molecular Flow Module is designed for accurately simulating flows in the free molecular flow regime. Historically, flows in this regime have been modeled by the direct simulation Monte Carlo (DSMC) method. This computes the trajectories of large numbers of randomized particles through the system, but introduces statistical noise into the modeling process. For low-velocity flows, such as those encountered in vacuum systems, the noise introduced by DSMC renders the simulations unfeasible.

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  • 该模型使用自由分子流接口中的角系数法和利用数学粒子追踪接口建立的 Monte Carlo 法(需要粒子追踪模块),计算通过 RF 耦合器的传输概率。 该模型使用自由分子流接口中的角系数法和利用数学粒子追踪接口建立的 Monte Carlo 法(需要粒子追踪模块),计算通过 RF 耦合器的传输概率。

Accurate Modeling of Low-Pressure, Low-Velocity Gas Flows

The Molecular Flow Module is designed to offer previously unavailable simulation capabilities for the accurate modeling of low-pressure gas flows in complex geometries. It is ideal for the simulation of vacuum systems, including those used in semiconductor processing, particle accelerators, and mass spectrometers. Small channel applications (e.g., shale gas exploration and flow in nanoporous materials) may also be addressed. The Molecular Flow Module uses the angular coefficient method to simulate steady-state free molecular flows, allowing the molecular flux, pressure, number density, and heat flux to be computed on surfaces. The number density can be reconstructed on domains, surfaces, edges, and points from the molecular flux on the surrounding surfaces. You can model isothermal and nonisothermal molecular flows and calculate the heat flux contribution from the gas molecules.

新型绝热技术为发展中国家运送疫苗

差动泵浦

离子注入器

排气管标准案例

RF 耦合器

旋转板

真空毛细管

负载锁定真空系统中的水吸收和解析

电荷交换单元仿真器