One-dimensional model and numerical solution to the viscous and heat-conducting micropolar real gas flow with homogeneous boundary conditions

Abstract The aim of this paper is to investigate the feasibility of well-posed lateral boundary conditions in a Fourier spectral semi-implicit semi-Lagrangian one-dimensional model. Two aspects are analyzed: (i) the complication of designing well-posed boundary conditions for a spectral semi-implicit scheme and (ii) the implications of such a lateral boundary treatment for the semi-Lagrangian trajectory computations at the lateral boundaries. Straightforwardly imposing boundary conditions in the gridpoint-explicit part of the semi-implicit time-marching scheme leads to numerical instabilities for time steps that are relevant in today’s numerical weather prediction applications. It is shown that an iterative scheme is capable of curing these instabilities. This new iterative boundary treatment has been tested in the framework of the one-dimensional shallow-water equations leading to a significant improvement in terms of stability. As far as the semi-Lagrangian part of the time scheme is concerned, the use of a trajectory truncation scheme has been found to be stable in experimental tests, even for large values of the advective Courant number. It is also demonstrated that a well-posed buffer zone can be successfully applied in this spectral context. A promising (but not easily implemented) alternative to these three above-referenced schemes has been tested and is also presented here.

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One-dimensional model on fuel penetration in diesel sprays with gas flow

International Journal of Automotive Technology ◽

10.1007/s12239-016-0010-4 ◽

2016 ◽

Vol 17 (1) ◽

pp. 109-118 ◽

Cited By ~ 2

Author(s):

M. Xu ◽

Y. C. Sun ◽

Y. Cui ◽

K. Y. Deng ◽

L. Shi

Keyword(s):

Gas Flow ◽

Dimensional Model ◽

Diesel Sprays ◽

One Dimensional

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Integrated modelling of internal combustion engine intake and exhaust systems

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/0957650011538622 ◽

2001 ◽

Vol 215 (4) ◽

pp. 495-506 ◽

Cited By ~ 6

Author(s):

O Chiavola

Keyword(s):

Internal Combustion Engines ◽

Gas Flow ◽

Complex Geometry ◽

Combustion Engine ◽

Internal Combustion ◽

Integrated Modelling ◽

Dimensional Model ◽

Three Dimensional Model ◽

One Dimensional ◽

Exhaust Systems

This paper presents a new method to analyse the unsteady gas flow in both intake and exhaust systems of internal combustion engines. Such a method is based on the simultaneous use of a one-dimensional model applied to describe the phenomena in ducts, together with a lumped parameter scheme to investigate the cylinder or other volume behaviour, coupled with a three-dimensional model, able to guarantee detailed information on flow behaviour in complex geometry, retaining the advantages of all methods, accuracy as well as fast processing and high flow pattern resolution. The description of the one-dimensional model developed with an example of its application is presented. The integrated approach with the coupling procedure is then described. Finally the results of a multicylinder exhaust system simulation are illustrated.

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