Authors: Keyvan Ghanbari (The university of Alabama in Huntsville), Gary P. Zank (The university of Alabama in Huntsville)

Shocks are common astrophysical structures that are frequently detected by human-made spacecraft in the solar wind at radial distances of several tens of solar radii up to the outer boundaries of the heliosphere. Interplanetary shocks originate from abrupt plasma eruptions/interaction events such as coronal mass ejections (CMEs)/stream interaction regions (SIRs). These structures travel away from the sun and eventually penetrate or get reflected by heliospheric termination shock (HTS) and heliopause. Voyagers 1 and 2 have identified multiple shock structures since crossing the heliopause and entering the very local interstellar medium (VLISM). The studies on these shocks have confirmed their distinctive features compared to the shocks investigated within the heliosphere. The VLISM shocks are weak and unusually broad which suggests that collisional processes are more likely to cause the dissipation mechanism. On appropriate scales compared to the collisional scale length, one can assume that the VLISM is weakly collisional. This implies that the VLISM shocks may be collisional rather than collisionless, despite their solar origin. Among many models used for plasma description, Braginskii-type fluid models are gaining much attention due to their higher accuracy in determining higher-order moments of the plasma. In this study, we use the model presented by Hunana et al 2022 who demonstrated a comprehensive evaluation of Brginskii-type fluid models up to 22 moments using Landau collision operators in different regimes. We obtain several derivatives of this model for simplified cases with and without the different components of the stress tensor and heat flux vector and solve them for a shock problem using the relaxation method. This helps us understand the effects of viscosity and heat flux on the collisional shock structures in the VLISM.