AMESim(CFD一维气体动力学库)

LMS http://b AMESim

CFD 1D Library Rev 12User’s guide

How to contact LMS http://bWeb site

Technical support

See here for e-mail addresses for your local office:

+33 4 77 23 60 30

Sales, pricing and general information

Phone

+33 4 77 23 60 31LMS Imagine S.A.7 place des Minimes42300 Roanne - France

Fax

Postal address

AMESim® User’s Guides

© Copyright LMS Imagine S.A. 1995-2013

The software described in this documentation is furnished under a license agreement. The software may be used or copied only under the terms of the license agreement. No part of this manual may be photo-copied or reproduced in any form without prior written consent from LMS Imagine S.A.Trademarks

AMESim® is a registered trademark of LMS Imagine S.A.AMESet® is a registered trademark of LMS Imagine S.A.AMERun® is a registered trademark of LMS Imagine S.A.AMECustom® is a registered trademark of LMS Imagine S.A.

LMS http://b® is a registered trademark of LMS International N.V.

LMS http://b Motion® is a registered trademark of LMS International N.V.SysDM® is a registered trademark of LMS International N.V.

System Synthesis® is a registered trademark of LMS International N.V.

Other product or brand names are trademarks or registered trademarks of their respective holders.

TABLE OF CONTENTS

1. Introduction ...................................................................................................................... 1 2. Getting started with the CFD 1D Gas Dynamics library ................................................ 1 3. Modeling the gas flow ...................................................................................................... 9 3.1. Flow variables ............................................................................................................ 9 3.2. Governing equations ................................................................................................ 10 3.3. Computation of friction term and Nusselt’s number ................................................. 11 3.4. Numerical scheme ................................................................................................... 12 4. CFD 1D Gas Dynamics library components ................................................................. 15 4.1. Pipes ........................................................................................................................ 15 4.2. 0D-1D Connections ................................................................................................. 17 4.3. 1D-1D Connections ................................................................................................. 28 5. Sensor devices ............................................................................................................... 40 5.1. CFD observer device ............................................................................................... 41 5.2. CFD signal plug ....................................................................................................... 42 6. Conclusion ...................................................................................................................... 43 REFERENCES ..................................................................................................................... 44

1. Introduction

The CFD 1D Gas Dynamics library is a special library that allows a significant improvement in simulation accuracy of gas flows in pipes and networks. It can be associated to the IFP-Engine, IFP-Exhaust or Pneumatic.

The CFD 1D Gas Dynamics library is not stand-alone and cannot be used without one of these 3 libraries.

The main feature of the CFD 1D Gas Dynamics library is the implementation of a 1D solver in the LMS http://b environment. The management of the 1D solver and the interfacing functions with the standard DOE solver is completely transparent to the user, leading to a fully integrated solution.

The 1D approach makes it possible to move forward in the physical description of gas dynamics in systems. Whereas the standard lumped approaches allows users to treat low velocity flows (Mach<0.3), the new tool breaks these limitations with the possibility to simulate the details of pressure waves and shocks with a high level of accuracy.

To visualize the 1D results, a new plot feature has been developed to follow the evolution of flow variables in space and time: the 1D plot. Using this 1D plot, the propagation of acoustic waves, shock, or the transport of species in the pipe can be analyzed.

Finally, it is assumed that the reader is familiar with the AMESim environment. If this is not the case, we suggest that you do some tutorial exercises provided in the AMESim manual before attempting the examples presented in this manual.

2. Getting started with the CFD 1D Gas Dynamics library

In order to get started using the components in the CFD 1D Gas Dynamics library, a simple model is considered, see Figure 1. It can be used to simulate the flow in a pipe between two infinite volumes with two different states. It can be seen in the figure that the Pneumatic library is used to model both the volume and the fluid properties. That library has been chosen as an example but the two others (IFP-Engine and IFP-Exhaust) could be used since they integrate the same kind of components for the gas properties definition and sources. We propose to build this system with AMESim, step by step.

Figure 1: getting started model, CFD 1D Gas Dynamics submodels in green and

pneumatic submodels in purple.

To model a network, select the CFD 1D Gas Dynamics category icon shown in Figure 2.

Figure 2: CFD 1D Gas Dynamics library category icon

The following subfolders appear: