  The He I 10830 \AA\ triplet is a very informative indicator of chromospheric
activities as the helium is the second most abundant element in the solar
atmosphere. Taking advantage of the high resolution of the 1.6 m Goode Solar
Telescope (GST) at Big Bear Solar Observatory (BBSO), previous observations
have shown clear evidence of the enhanced absorption, instead of
typically-observed emission, for two M-class flares. In this study, we analyze
the evolution of the He I 10830 10830 \AA\ emission in numerical models and
compare it with observations. The models represent the RADYN simulation results
obtained from the F-CHROMA database. We consider the models with the injected
electron spectra parameters close to observational estimates for the
2013-August-17 flare event ($\delta=8$, $E_c = \{15,20\}$ keV, $F=\{1\times
10^{11}, 3\times{}10^{11}\}$ erg cm$^{-2}$) in detail, as well as other
available models. The modeling results agree well with observations, in the
sense of both the maximum intensity decrease (-17.1%, compared to the observed
value of -13.7%) and the trend of temporal variation (initial absorption phase
followed by the emission). All models demonstrate the increased number
densities and decreased ratio of the upper and lower level populations of He I
10830 10830 \AA\ transition in the initial phase, which enhances the opacity
and forms an absorption feature. Models suggest that the temperatures and free
electron densities at heights of 1.3-1.5 Mm should be larger than $\sim 10^4$ K
and $6\times 10^{11}$ cm$^{-3}$ thresholds for the line to start being in
emission.
