Convective Overshoot Daniel Lecoanet Josiah Schwab, Eliot Quataert - - PowerPoint PPT Presentation

▶
convective overshoot
SMART_READER_LITE
LIVE PREVIEW

Convective Overshoot Daniel Lecoanet Josiah Schwab, Eliot Quataert - - PowerPoint PPT Presentation

Jan 25, 2024 221 likes •746 views

The Turbulent Diffusivity of Convective Overshoot Daniel Lecoanet Josiah Schwab, Eliot Quataert Lars Bildsten, Frank Timmes Geoff Vasil, Keaton Burns Jeff Oishi, Ben Brown Supported by: NSF, Hertz Foundation, NASA, ARC The problem Stably

slide-1
SLIDE 1

The Turbulent Diffusivity of Convective Overshoot

Daniel Lecoanet Josiah Schwab, Eliot Quataert

Lars Bildsten, Frank Timmes

Geoff Vasil, Keaton Burns Jeff Oishi, Ben Brown

Supported by: NSF, Hertz Foundation, NASA, ARC

slide-2
SLIDE 2

The problem

Convection Stably stratified

slide-3
SLIDE 3

The problem

Convection Stably stratified

slide-4
SLIDE 4

The problem

Convection Stably stratified

how much mix ixing? what kin ind?

slide-5
SLIDE 5

Super Asymptotic Giant Branch stars

MS

H

slide-6
SLIDE 6

MS

H He

RGB

Super Asymptotic Giant Branch stars

slide-7
SLIDE 7

MS

H He CO

RGB AGB

Super Asymptotic Giant Branch stars

slide-8
SLIDE 8

MS

H He CO

RGB AGB

Super Asymptotic Giant Branch stars

slide-9
SLIDE 9

MS

H He CO

RGB AGB

Super Asymptotic Giant Branch stars

SAGB

slide-10
SLIDE 10

Frank Timmes Temperature Carbon Density

Energy Generation

Flame Inner star Outer star

slide-11
SLIDE 11

Farmer+ 2015

slide-12
SLIDE 12

Does flame reach center???

Farmer+ 2015

slide-13
SLIDE 13

Does flame reach center???

Yes: ONe core e- capture SNe SNe II-P Farmer+ 2015

slide-14
SLIDE 14

Does flame reach center???

Yes: ONe core e- capture SNe SNe II-P No: ``Hybrid’’ WD SNe Ia? ??? Farmer+ 2015

slide-15
SLIDE 15

Carbon Flames

slide-16
SLIDE 16

Carbon Flames

slide-17
SLIDE 17

Carbon Flames

flame dies

slide-18
SLIDE 18

Carbon Flames

flame dies flame is fine

slide-19
SLIDE 19

Carbon Flames

flame dies flame is fine

slide-20
SLIDE 20

Carbon Flames Properties

slide-21
SLIDE 21

Carbon Flames Properties

slide-22
SLIDE 22

Carbon Flames Properties

slide-23
SLIDE 23

Carbon Flames Model

slide-24
SLIDE 24

Carbon Flames Model

negative in conv VERY positive in flame

slide-25
SLIDE 25

Carbon Flames Model

slide-26
SLIDE 26

Carbon Flames Model

BC’s: no slip, no temperature perturbation 3D domain, 4H x 4H x 2H

slide-27
SLIDE 27

Carbon Flames Model

BC’s: no slip, no temperature perturbation 3D domain, 4H x 4H x 2H

slide-28
SLIDE 28

Carbon Flames Properties

slide-29
SLIDE 29

Carbon Flames Properties

slide-30
SLIDE 30

Dedalus

Pseudo-spectral Open-source Pyth ython ** **Very

ry fl flexible equations

slide-31
SLIDE 31

The team so far

Daniel Lecoanet (Berkeley) Keaton Burns (MIT) Jeff Oishi (Bates College) Ben Brown (Colorado) Geoff Vasil (Sydney)

slide-32
SLIDE 32

flame

slide-33
SLIDE 33
slide-34
SLIDE 34
slide-35
SLIDE 35
slide-36
SLIDE 36
slide-37
SLIDE 37

Passive Scalar Field

slide-38
SLIDE 38

Passive Scalar Field

slide-39
SLIDE 39

Passive Scalar Field

slide-40
SLIDE 40

Passive Scalar Field

slide-41
SLIDE 41

Passive Scalar Field

Ansatz:

slide-42
SLIDE 42

Passive Scalar Field

slide-43
SLIDE 43

Turbulent Diffusivity

slide-44
SLIDE 44

Turbulent Diffusivity

Solve: Does it work?

slide-45
SLIDE 45

Turbulent Diffusivity

Solve: Does it work? fit

slide-46
SLIDE 46
slide-47
SLIDE 47

Turbulent Diffusivity

Solve: Turbulent diffusivity is a good approximation!

slide-48
SLIDE 48

Do Carbon Flames Mix?

Need deep within the flame

slide-49
SLIDE 49
slide-50
SLIDE 50

Conclusion

  • 1. Penetrative convection mixes fluid like a turbulent

diffusivity

  • 2. Very little mixing in regions which are very stable
  • 3. Convective overshoot probably can’t stall flames
slide-51
SLIDE 51