Preprint Article Version 1 This version is not peer-reviewed

Numerical Analysis of Knudsen Number of Helium Flow Through Gas-Focused Liquid Sheet Micro-Nozzle

Version 1 : Received: 29 October 2024 / Approved: 29 October 2024 / Online: 29 October 2024 (13:07:03 CET)

How to cite: Kovačič, K.; Bajt, S.; Šarler, B. Numerical Analysis of Knudsen Number of Helium Flow Through Gas-Focused Liquid Sheet Micro-Nozzle. Preprints 2024, 2024102316. https://doi.org/10.20944/preprints202410.2316.v1 Kovačič, K.; Bajt, S.; Šarler, B. Numerical Analysis of Knudsen Number of Helium Flow Through Gas-Focused Liquid Sheet Micro-Nozzle. Preprints 2024, 2024102316. https://doi.org/10.20944/preprints202410.2316.v1

Abstract

This work aims to verify whether the continuum mechanics assumption holds for the numerical simulation of a typical sample delivery system in Serial Femtosecond Crystallography (SFX). Knudsen numbers were calculated based on the numerical simulation results of helium flow through the gas-focused liquid sheet nozzle into the vacuum chamber, representing the upper limit of Knudsen number for such systems. The analysed flow is considered steady, compressible and laminar. The numerical results are mesh-independent, with a Grid Convergence Index significantly lower than 1 % for global and local analysis. The study is based on an improved definition of the numerical Knudsen number, a combination of cell Knudsen number and physical Knudsen number. In the analysis, no-slip boundary and low-pressure boundary slip conditions are compared. No significant differences are observed. The study justifies using computational fluid dynamics (CFD) analysis for SFX sample delivery systems based on the assumption of continuum mechanics.

Keywords

Knudsen number; compressible hypersonic flow; vacuum; liquid sheet nozzle; sample delivery system; CFD

Subject

Engineering, Mechanical Engineering

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.