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Full-Text Articles in Mechanical Engineering

Rarefication Effects On Jet Impingement Loads, Shiying Cai, Chunpei Cai, Kai Zhang, Jun Li Sep 2017

Rarefication Effects On Jet Impingement Loads, Shiying Cai, Chunpei Cai, Kai Zhang, Jun Li

Michigan Tech Publications

Rarefication effects on jet impingement loads are studied by comparing recent new formulas at the collisionless flow limit and numerical simulations. The jet exit size is finite, and can be either planar or round. In the simulations, the jets have different degrees of rarefication, with a Knudsen (Kn) number ranging from 0 to infinity; i.e., the jet flows can be continuum, collisional, or collisionless. The comparison results indicate that (1) the new surface load formulas are accurate at the collisionless flow limit; (2) in general, the formulas offer upper limits for the peak loads; (3) however, it is improper ...


A New Gaskinetic Model To Analyze Background Flow Effects On Weak Gaseous Jet Flows From Electric Propulsion Devices, Chunpei Cai Jan 2017

A New Gaskinetic Model To Analyze Background Flow Effects On Weak Gaseous Jet Flows From Electric Propulsion Devices, Chunpei Cai

Michigan Tech Publications

Recent work on studying rarefied background and jet flow interactions is reported. A new gaskinetic method is developed to investigate two closely related problems. The first problem is how a collisionless background flow can affect a highly rarefied jet flow. The rarefied jet and background flow conditions are assumed available and described with seven parameters. Gaskinetic theories are applied and formulas are obtained for the mixture properties. Simulations are performed to validate these expressions, and excellent agreement is obtained. The second problem is to recover the collisionless background and jet flow parameters with limited measurements. A group of linearized equations ...