We present a comprehensive analysis of the three-dimensional magnetic flux
rope structure generated during the Lynch et al. (2019) magnetohydrodynamic
(MHD) simulation of a global-scale, 360 degree-wide streamer blowout coronal
mass ejection (CME) eruption. We create both fixed and moving synthetic
spacecraft to generate time series of the MHD variables through different
regions of the flux rope CME. Our moving spacecraft trajectories are derived
from the spatial coordinates of Parker Solar Probe's past encounters 7 and 9
and future encounter 23. Each synthetic time series through the simulation flux
rope ejecta is fit with three different in-situ flux rope models commonly used
to characterize the large-scale, coherent magnetic field rotations observed in
a significant fraction of interplanetary CMEs (ICMEs). We present each of the
in-situ flux rope model fits to the simulation data and discuss the
similarities and differences between the model fits and the MHD simulation's
flux rope spatial orientations, field strengths and rotations, expansion
profiles, and magnetic flux content. We compare in-situ model properties to
those calculated with the MHD data for both classic bipolar and unipolar ICME
flux rope configurations as well as more problematic profiles such as those
with a significant radial component to the flux rope axis orientation or
profiles obtained with large impact parameters. We find general agreement among
the in-situ flux rope fitting results for the classic profiles and much more
variation among results for the problematic profiles. We also examine the
force-free assumption for a subset of the flux rope models and quantify
properties of the Lorentz force within MHD ejecta intervals. We conclude that
the in-situ flux rope models are generally a decent approximation to the field
structure, but all the caveats associated with in-situ flux rope models will
still apply...
