Correction to: Rarefied gas flow into vacuum through a channel with sudden contraction or expansion

Investigation of Newtonian Fluid Flow through a Two- dimensional Sudden Expansion and Sudden Contraction Flow Passage

–The importance of flow through sudden change in flow passages lies in the numerous industrial applications such as, polymer processing, injection molding, biomedical instruments, extrusion, thermoforming etc. In this work, fluid flow through an axi-symmetric sudden contraction flow passages has been carried out using commercial CFD tools. Flow in the inverse direction, which represents flow th...

Turbulent flow through a plane sudden expansion

The results are reported of an experimental investigation of turbulent flow through a plane sudden expansion of expansion ratio R=D/d=4 and aspect ratio A= w/h=5.33. It is well known that plane sudden expansions with R greater than 1.5 produce asymmetric flows and this was again seen in this study. The literature for the asymmetric situation (R>1.5) is surprisingly limited and only axial veloci...

Rarefied Background Flow in a Vacuum Chamber

Spacecraft propulsion systems, such as Hall thrusters, are designed and tested in large vacuum chambers. The pumping capacity of modern facilities makes it possible to maintain pressures as low as 3 10 4 10 Pa. In this study, several free molecular models are developed to analyze the background flow inside a vacuum chamber. These models lead to various sets of analytical results including veloc...

Rarefied gas dynamics and its applications to vacuum technology

Basic concepts of rarefied gas dynamics are given in a concise form. Some problems of rarefied gas flows are considered, namely, calculations of velocity slip and temperature jump coefficients, gas flow through a tube due to pressure and temperature gradients, and gas flow through a thin orifice. Results on the two last problems are given over the whole range of gas rarefaction. A methodology f...

Expansion of a Finite Mass of Gas into Vacuum