We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure coreplatform@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This paper considers the relationship between nonlinearly interacting helical flow disturbances and flame area response in a swirling premixed flame. The present study was performed to determine whether there are nonlinear mechanisms through which helical modes ($m_{u}\neq 0$) can lead to non-zero unsteady heat release rate oscillations. The results show that for single frequency content (at $\unicode[STIX]{x1D714}_{0}$), helical modes excite unsteady heat release rate response of $O(\unicode[STIX]{x1D716}^{3})$ and that two-frequency excitation (e.g. at $\unicode[STIX]{x1D714}_{0}$ and $2\unicode[STIX]{x1D714}_{0}$), leads to a response of $O(\unicode[STIX]{x1D716}^{2})$ at $\unicode[STIX]{x1D714}_{0}$. There are two mechanisms through which this can occur: First, helical flow disturbances can distort the time-averaged flame shape to have an azimuthal component that matches that of the incident disturbance, $\exp (im_{u}\unicode[STIX]{x1D703})$. Second, multiple helical modes can nonlinearly interact to cause axisymmetric unsteady flame wrinkling. The paper derives the various modal contributions in the incident velocity disturbance that satisfy these criteria. These results suggest that it is only the $m_{u}=0$ mode which controls the linear dynamics (e.g. instability inception conditions) of these flames (where $\unicode[STIX]{x1D716}\ll 1$), but that their nonlinear dynamics is also controlled by the $m_{u}\neq 0$ helical modes.
Recommend this
Email your librarian or administrator to recommend adding this to your organisation's collection.