22.10.2014 Views

THESE de DOCTORAT - cerfacs

THESE de DOCTORAT - cerfacs

THESE de DOCTORAT - cerfacs

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

CONTENTS 5<br />

6.4 Transmitted and reflected acoustic waves in isentropic nozzles . . . . . . . . . . 103<br />

6.4.1 Acoustic Response of Chocked and Unchocked Nozzles . . . . . . . . . . 104<br />

6.4.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106<br />

6.5 When entropy does not remain constant through a duct . . . . . . . . . . . . . . 106<br />

6.5.1 Analytic Solution : Building the linear system of equations . . . . . . . . 108<br />

6.5.2 The mean flow in SNozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . 109<br />

6.5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111<br />

6.6 Transmitted and Reflected Waves through an i<strong>de</strong>al Compressor: the enthalpy<br />

jump case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112<br />

6.6.1 Building the linear system of equations for the analytical solution . . . . 112<br />

6.6.2 The mean flow in SNozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . 114<br />

6.6.3 Introducing π c in the momentum equation . . . . . . . . . . . . . . . . . 114<br />

6.6.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117<br />

7 Computation of the Reflection Coefficient on the Inlet air circuit of an Helicopter<br />

combustor chamber 120<br />

7.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120<br />

7.2 Mean parameters of the Intake Duct . . . . . . . . . . . . . . . . . . . . . . . . . 121<br />

7.3 Acoustic Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123<br />

7.4 Helmholtz Solver Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124<br />

7.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127<br />

A About the π ′ c = 0 assumption 135<br />

A.1 When is π<br />

T ′ equal to zero? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135<br />

B Publications 139

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!