[FLASH-USERS] Debugging differences between 1D and 2D laser deposition

[Graeme D Sutcliffe]

Hi FLASH users,

I have been unable to tease out an explanation for discrepancy between
simulations, so I turn to you for any tips on how to further debug why I am
seeing differences between 1D and 2D simulations of ostensibly identical
systems.

I ran a series of 1D cartesian and 2D cylindrical simulations of
laser-driven foils (starting from the laserslab template). The foils were
aligned with target normals along a common axis and driven on the
outward-facing surfaces.

My conundrum is this: the arrival time of the shocks at the center of the
domain in 2D is *faster *than in 1D by about a factor of 2.5 (for example,
in a 12 um thick CH foil case, the 1D shock converges at ~7.7 ns while
the 2D shock converges is at ~3.1 ns). This is counterintuitive for me: I
would expect the 1D simulations to be faster because of better laser
coupling (because of the nonzero beam incidence angle in the 2D sim) and
the lack of expansion into the second spatial dimension. I think I must be
making a mistake in configuring my laser drive in one of the two
configurations.

Here is some basic information:
Beam incidence angle (relative to target normals):
1D: 0 degrees
2D: 33 degrees

Key runtime parameters (common for both cases):
ed_laser3Din2D = .false.
ed_adjustBeamsTargetIntensity = .true.
ed_gridType_1 = "statistical1D"
Beam power profile: the same (4.5e12 W peak)
Beam spatial profile: gaussian with radius 224e-4 cm

Any tips on where to look next or suggested tests that I can run?

Thanks,
Graeme Sutcliffe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20231208/4743284d/attachment.htm>