An Experimental and Numerical Analysis of the Influence of Surface Roughness on Supersonic Flow in a Nozzle Under Atmospheric and Low-Pressure Conditions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26220%2F25%3APU156240" target="_blank" >RIV/00216305:26220/25:PU156240 - isvavai.cz</a>

Result on the web

<a href="https://www.mdpi.com/2227-7080/13/4/160" target="_blank" >https://www.mdpi.com/2227-7080/13/4/160</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/technologies13040160" target="_blank" >10.3390/technologies13040160</a>

Result language

angličtina

Original language name

An Experimental and Numerical Analysis of the Influence of Surface Roughness on Supersonic Flow in a Nozzle Under Atmospheric and Low-Pressure Conditions

Original language description

The ongoing research in Environmental Scanning Electron Microscopy (ESEM) is contrib-uted to in this paper. Specifically, this study investigates supersonic flow in a nozzle ap-erture under low-pressure conditions at the continuum mechanics boundary. This phe-nomenon is prevalent in the differentially pumped chamber of an ESEM, which separates two regions with a significant pressure gradient using an aperture with a pressure ratio of approximately 10:1 in the range of 10,000 to 100 Pa. The influence of nozzle wall rough-ness on the boundary layer characteristics and its subsequent impact on the oblique shock wave behavior, and consequently, on the static pressure distribution along the flow axis, is solved in this paper. It demonstrates the significant effect of varying inertial-to-viscous force ratios at low pressures on the resulting impact of roughness on the oblique shock wave characteristics. The resulting oblique shock wave distribution significantly affects the static pressure profile along the axis, which can substantially influence the scattering and loss of the primary electron beam traversing the differential pumping stage. This, in turn, affects the sharpness of the resulting image. The boundary layer within the nozzle plays a crucial role in determining the overall flow characteristics and indirectly affects beam scattering. This study examines the influence of surface roughness and quality of the manufactured nozzle on the resulting flow behavior. The initial results obtained from ex-perimental measurements using pressure sensors, when compared to CFD simulation re-sults, demonstrate the necessity of accurately setting roughness values in CFD calcula-tions to ensure accurate results. The CFD simulation has been validated against experi-mental data, enabling further simulations. The research combines physical theory, CFD simulations, advanced experimental sensing techniques, and precision manufacturing technologies for the critical components of the exp

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20201 - Electrical and electronic engineering

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Technologies - MDPI

ISSN

2227-7080

e-ISSN

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Volume of the periodical

13

Issue of the periodical within the volume

4

Country of publishing house

CH - SWITZERLAND

Number of pages

33

Pages from-to

1-33

UT code for WoS article

001474315200001

EID of the result in the Scopus database

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