Permeability Modeling of the Mars 2020 Parachute Broadcloth Materials

The broadcloth material used in parachute manufacturing is generally a thin, woven,permeable textile. The small length scales of fibers, pores, and gaps in fabric are challenging to spatially resolve in a full-scale parachute simulation. In this work, simulations are performed using a 3D reconstruction of the broadcloth material used in the Mars 2020 mission, and simulation results using the detailed reconstructed geometry are compared to the simplified model proposed in previous work. Furthermore, results from simulations under Earth ambient lab conditions are compared to experimental permeability test data to validate the choice of parameters for this reduced-order model. Simulations under ASPIRE SR03 flight-relevant conditions are also performed to study permeability in a rarefied flow regime. It is observed that flow through the material is similar to a developing pipe flow, and under low-density conditions, significant slip velocity is present inside pores. For all conditions investigated, the pressure drag is the primary contributor to the total drag force. Drag and mass flow rate discrepancies are observed between models, motivating future work to investigate the sensitivity of system-level parachute FSI simulations to the assumed permeability model and associated parameters.