Search found 8 matches

by pjuelsgaard
Mon May 30, 2022 8:06 am
Forum: General Discussion
Topic: Sign relation between damping rate and Imaginary frequency
Replies: 12
Views: 4268

Re: Sign relation between damping rate and Imaginary frequency

Going through the final touches, I notice that part of this analysis doesn't quite add up for me. If the mode angular frequency agrees with the dimensionless frequency, as in sign(sigma)=sign(omega), and the time dependence is amplitude ~ exp(-i sigma t) Then this would lead to amplitude ~ exp(-i si...
by pjuelsgaard
Sat May 28, 2022 2:18 pm
Forum: General Discussion
Topic: Understanding the displacement vector
Replies: 1
Views: 1290

Understanding the displacement vector

The physics behind the displacement vector, specifically the radial part (\xi_r), confuse me a bit, Using the relation between lagrangian and eulerian perturbations for scalar quantities, it quickly becomes apparent that \delta r = r' + \xi_r However, I have some nagging feeling in the back of my mi...
by pjuelsgaard
Fri May 13, 2022 1:29 pm
Forum: General Discussion
Topic: Clarification on oscillation eqations : omega_c
Replies: 1
Views: 1240

Clarification on oscillation eqations : omega_c

I am somewhat confused, trying to understand the oscillation equations completely. Many of them contain the term \omega_c. Is this the acoustical cutoff frequency for the model, or, as I think it might be in $GYRE_DIR/src/context/gyre_context.fpp, is it just the corotating frequency (which would the...
by pjuelsgaard
Tue Apr 26, 2022 2:16 am
Forum: General Discussion
Topic: Sign relation between damping rate and Imaginary frequency
Replies: 12
Views: 4268

Re: Sign relation between damping rate and Imaginary frequency

Thanks for the detailed explanation. I was having a hard time wrapping my head around it.

Also, Günter Houdek sends his regards (he's my thesis advisor)
by pjuelsgaard
Mon Apr 25, 2022 7:15 am
Forum: General Discussion
Topic: Sign relation between damping rate and Imaginary frequency
Replies: 12
Views: 4268

Sign relation between damping rate and Imaginary frequency

When doing non-adiabatic frequencies, I am having a hard time figuring out the significance of the relation between the sign of the imaginary part of the eigenfrequency and the damping rate. Does anyone know the relation,or how to figure it out from the GYRE odcumentation? Kind regards - Peter Juels...
by pjuelsgaard
Thu Apr 21, 2022 4:33 am
Forum: General Discussion
Topic: Opacity partial deriv. definition
Replies: 2
Views: 1368

Re: Opacity partial deriv. definition

Thanks a lot.
Now my models make a lot more sense
by pjuelsgaard
Wed Mar 30, 2022 4:53 am
Forum: General Discussion
Topic: Opacity partial deriv. definition
Replies: 2
Views: 1368

Opacity partial deriv. definition

Hi. tl;dr: How are the opacity derivatives kap_T and kap_rho defined? I have issues with a model and the amplitude of the opacity derivatives, with the shape of the slope being more or less correct, when compared to a similar model computed with MESA, but the amplitudes are vastly different (For kap...
by pjuelsgaard
Mon Jan 10, 2022 8:20 am
Forum: General Discussion
Topic: AMDL-format lacking structure coefficients c_thn
Replies: 2
Views: 1524

AMDL-format lacking structure coefficients c_thn

Hi all. I'm trying to run NAd calculations with an AMDL file. As such, I am missing some structure coefficients, namely the nabla_ad and c_thn. nabla_ad = adiabatic temperature gradient, if I am not mistaken, but what is c_thn? I am thinking of modifying the amdl-reading routine on my local installa...